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actpd (On the action of nitric) on the esters of methyl-phenylaminoformic acid. 451. — (On the nitration of orthochloro- and orthobromobenzoic). 462. ADRIANI (J. H.). /Eutectie curves in systems of three substances of which two are optical antipodes”. 463. AGE of the Earth (The amount of the circulation of the carbonate of lime and the), (1). 48. (IL). 116. AGGLUTINATIVE substances. See SuBSTANCES. AGONIADINE (Plumieride and its identity with). 35. ALBERDA VAN EKENSTEIN (w.). See Lopry pz Bruyn (C. A). ALPINIA malaccensis Rose. (On the essential oil from the leaves of). 451. ANHARMONIC ratio. See Rario. ANTIPODES (Hutectic curves in systems of three substances of which two are optical). 463. Astronomy. E. I’. van pe Sanpe Bakauyzen: The motion of the Pole of the Earth according to the observations of the last years”. 157. — H. G. van pe Sanpe Bakuuyzen: /Report of the Committee for the organi- zation of the observations of the solar eclipse on May 18th 1901”. 529. — J. C, Kapreyn: On the luminosity of the fixed stars”. 658. ATMOSPHERIC PRESSURE (Measurements on the magnetic rotation of the plane of pola risation in liquefied gases under). (I). 70. ATTRACTION (On the relation between radiation and molecular). 27. Bacteriology. M. W. Berertnck: vOn different forms of hereditary variation of microbes”. 352. — M. W. Berertnex: On oligonitrophilous Bacteria”. 586. BAKHUIS ROOZEBOOM (H. W.) presents a paper of Dr. Ernst Conen and H. Rakxen: /The solubility of calciumearbonate in sea-water”. 63. — The behaviour of mixtures of mercuric-iodide and silver-iodide, 84. — presents a paper of Dr. A. Smits: 7A new method for the exact determination of the boiling-point”. 86, — presents a paper of Dr, Ernst Conen : Thermodynamics of standard-cells”. (Ll). 91. (IID). 208. — presents a paper of Dr, Ernst Conen : ”The Enantiotropy of ‘lin’. (V). 93. (VD. 469. — presents a paper of Dr. C. van Eyx: /The formation of mixed crystals of Thalliumnitrate and Thalliumiodide”. 98. — presents a paper of Dr. A. Smits: On soap-solutions”. 138. 48 Proceedings Royal Acad. Amsterdam. Vol. III.

II CLOGNy DIEGN TE:

BAKHUIS ROOZEBOOM (H. W.) presents a paper of Dr. Erxst Conen: The metastability of the Weston-Cadmiumeell and its insuitability as standard of electromotive force”. 217.

— presents a paper of Dr. Ernsr Conen: /Experimental determination of the limiting heat of solution”. 327. — presents a paper of Dr. Ernst Conen: The Weston-Cadmiumeell”. 380.

— presents a paper of Dr. J. H. Aprranr: Eutectic curves in systems of three substances of which two are optical antipodes”. 463.

— presents a paper of Dr. H. B. Hotssorr: On heats of solution in general, that of Cd SO,, 8/; H,O in particular”. 467.

— presents a paper of Dr. A. Smits: /Determination of the decrease of vapour- tension of a solution of NaCl at higher temperature”. 503. — presents a paper of Dr. A. Smits: /Some observations on the results obtained in the determination of the decrease in vapour-tension and of the lowering of the freezing-point of solutions, which are not very dilute”. 507. — presents a paper of Dr. Ernst Conen and E. H. Bucnner: /Etarp’s Law of solubility”. 561. —- presents a paper of Dr. C. H. Wryp: On the irregularities of the cadmium standard cell”. 595. — presents a paper of Dr. A. Smits: ”On the progressive change of the factor 7 as function of the concentration”. 717. BAKHUYZEN (E. F. VAN DE SANDE). See SANDE Baknuyzen (I. F. van DE). BAKHUYZEN (H. G. VAN DE SAND#). See SANDE Baknuyzen (H. G. van De). BAKKER (G.). Contribution to the theory of elastic substances. 473. BEMMELEN (J. F. VAN). Further results of an investigation of the Monotreme- skull. 130. — 3r4 Note. 405. BEMMELEN (J. M. VAN) presents a paper of Dr. F. A, H. ScurermeMaAKErs: vOn the composition of the vapourphase in the system: Water-Phenol, with one and with two liquid-phases”’. 1. — presents a paper of Prof. Eve. Dunots: The amount of the circulation of the Carbonate of Lime and the age of the earth’. (Q. 43. (IL). 116. — On the system: Bi,O,—N,O,—H,0. 196. — presents a paper of Dr. F. A. H. Scurernemakers: “Notes on Equilibria in ternary systems”. 701. BEIERINCK (mM. w.). Further researches on the formation of Indigo from the Wond (Isatis tinctoria). LOI. — On different forms of hereditary variation of microbes. 352. — On the development of Buds and Bud-variations in Cytisus Adami. 365. — On oligonitrophilous Bacteria. 586. HEWERMAN (H. d,), Curious disturbances of the sensation of pain ina case of tabes dorsalis. 253, — On the influence upon respiration of the faradie stimulation of nerve tracts passing through the internal eapsula, 689,

BILE (Researches on the secretion and e »mposition of) in living men, 584,

CONTENTS. Ii

BisMuTH (The Haut-effect and the increase of resistance of) in the magnetic-field at very low temperatures. (IL). 177.

— (Crystals of). See Crystats. BISMUTHNITRATE and Water (Qn the system). 196. BLANKSMA (J. J.). Organic polysulfides and the polysulfides of sodium, 457. BLooDcoRPUsCLES (On the resisting power of the red). 76.

— (On the permeability of the red) for NO,- and SO,-ions. 371. BLOODsERUM (On the durability of the agglutinative substances of the). 41. BOILING-PoINT (A new method for the exact determination of the). 86. BOLTZMANN’s and Wren’s Laws of radiation. 607.

BONNEMA (J. H.). Leperditia baltica His. sp. their identity with Leperditia Eich- waldi Fr. v. Schm. and their being found in Groningen diluvial erraties. 137.

— On the occurrence of remains of Leperditia grandis Schrenck sp. in the erratic blocks of the Groningen diluvium. 545.

Botanics. M. W. Beterrscx: Further researches on the formation of Indigo from the Woad (Isatis tinctoria)’’. 101.

—C. A. J. A. Ouprmans: Contributions to the knowledge of some undescribed or imperfectly known fungi”. (L). 140. (IL). 230. (III). 332. (IV). 386. — Hueco ve Vries: 7On the origin of new species of plants”. 245. — W. Borck: Preservatives on the stigma against the germination of foreign Pollen’. (Communicated by Prof. Hugo pE Vries). 264. — M. W. Bewerrmck: On the development of Buds- and Bud-variations on Cytisus Adami”. 365. — F. A. F. C. Went: /On the influence of nutrition on the secretion of Enzymes by Monilia sitophila (Mont.) Sace.” 489. — S. L. Scnouren: A pure culture of Saprolegniaceae”. (Communicated by Prof. F. A. F. C. Went). 60). BOUDIN (m.). See KamprtincH Onnes (H.). BRAND (J.). Researches on the secretion and composition of bile in living men. 584, BRUYN (c. A. LOBRY D&#). See Lory DE Bruyn (C. A.). BUCHNER (&, H.). See Conen (Ernst). BuDs and Bud-variations (On the development of) in Cytisus Adami. 365. BURCK (w.), Preservatives on the stigma against the germination of foreign Pollen. 264, CADMIUMCELL (The metastability of the) and its insuitability as standard of electro- motive force. 217. — (The Weston). 380. CADMIUM standard cell (On the irregularities of the). 595. CALCIUMCARBONATE (The solubility of) in sea-water. 63. — See also Carponate of Lime. CARBONATE of lime (The amount of the circulation of the) and the age of the Earth. (1). 48. (IT). 116. — See also CALCIUMCARBONATE. CHANGE (On the progressive) of the factor ¢ as function of the concentration. 717.

48*

re a ee Se

Iv COON YT EN Rs.

Chemistry. F. A. H. Scurervemakers: ,On the composition of the vapour-phase in the system: Water-Phenol, with one and with two liquid-phases. (Communicated by Prof. J. M. vAN BEMMELEN). 1. — M. Gresnorr: ”Echinopsine, a new crystalline vegetable base”. (Communicated by Prof. A. P. N. Francuront). 11. — A. P. N. FrancurMont: /Plumieride and its identity with Agoniadine.” 35.

— P. van Rompurcu: On the crystallised constituent of the essential oil of Kaempferia Galanga L.” 38.

— Ernst Cowen and H. Raken: The solubility of calcium carbonate in sea-water.” (Communicated by Prof. H. W. Baxuurs Roozrgoom). 63.

— H. W. Baxkavis Roozesoom: The behaviour of mixtures of mercuric-iodide and silver-iodide.” 84.

— A. Smits: vA new method for the exact determination of the Boiling-point”. (Communicated by Prof. H. W. Baxuurs RoozEBoom), 36.

— Ernst ConEen: /Thermodynamics of standard cells”. (Communicated by Prof. H. W. Baxuurs RoozEsoom). (If). 91. (I11). 208.

— Ernst Conen: The Enantiotropy of Tin”. (Communicated by Prof. H. W. Baxauts Roozesoom). (V). 93 (VI). 469.

—- C. van Eyx: /The formation of mixed crystals of Thallium nitrate and Thallium * iodide”. (Communicated by Prof. H. W. Baknurts RoozEsoom). 98.

— A. Smits: ”On soap-solutions”. (Communicated by Prof. H. W. Bakauts Rooze- BOOM). 133.

— J. M. van Bemmeten: On the system: Bi,0,—N,0,—H,0”. 196.

— A. P. N. Francurmont presents the dissertation of Dr. L. van SCHERPENZEEL: vYhe action of hydrogen nitrate (real nitric acid) and the three toluic acids and some of their derivatives”. 203.

— Erysr Conen: The metastability of the Weston-cadmiumcell and its insuitability as standard of electromotive force”. (Communicated by Prof. H. W. Bakuurs Roozesoom). 217.

— fevst Conen: ”Experimental determination of the limiting heat of solution”. (Communicated by Prof. H. W. Baknurs Roozesoom). 327.

— U. A, Losey br Bruyn: /Review of the results of a comparative study of the three dinitrobenzenes”. 375.

— Enysr Courn: The Weston-cadmiumcell”, (Communicated by Prof. H. W. Baknurs Roozenoom). 380,

— ©. A, Losey pe Bruyn and W. Atperpa van Mikenstein: 7A new kind of formal- (methylene-) compounds of some oxy-acids”, 400.

— P. van Rompuron: /On the essential oil from the leaves of Alpinia malaccensis Rose”. 451,

— P. van Rompuron: ,On the action of nitric acid on the esters of methyl- phenylaminoformic acid’. 451,

— P. van Romiunai: »On the essential oil from Ocimum Basilicum L”. 454.

— J.J. Bianksma: Organic polysulfides and the polysulfides of sodium”, (Com- munieated by Prof, ©, A. Loony pe Bruyn). 457,

CONTENTS. Vv

Chemistry. N. ScHoort: ,On urea derivatives of sugars”. (Communicated by Prof. C. A. Lopry DE Bruyn). 459. — A. F. Hotreman: On the nitration of orthochloro- and orthobromobenzoie acid”. (Communicated by Prof. C. A. Lopry DE Bruyn). 462. — J. H. Avrianr: Eutectic curves in systems of three substances of which two are optical antipodes”. (Communicated by Prof. H. W. Bakuuis Roozezoom). 463. — H. B. Hotsporr: On heats of solution in general, that of Cd SO,,°/, H,O in particular”, (Communicated by Prof. H. W. Bakuurs RoozeBoom). 467. — A. Smits: /Determination of the decrease of vapour-tension of a solution of NaCl at higher temperature”. (Communicated by Prof. H. W. Baknuis RoozeBoom). 503, — A. Smits: /Some observations on the results obtained in the determination of the decrease in vapour-tension and of the lowering of the freezing-point of solutions, which are not very dilute”. (Communicated by Prof. H. W. Bakuurs Roozesoom). 507. — Ernst Conen and E. H. Bucuner: /Etarp’s law of solubility”. (Communicated by Prof. H. W. Bakutis Roozesoom). 561. — ©. H. Winn: /On the irregularities of the cadmium standard cell”. (Communi- eated by Prof. H. W. Baxaurs RoozEpoom). 595. — Ff. A. H. Scureinemakers: /Notes on Equilibria in ternary systems’’, (Commu- nicated by Prof. J. M. van BemMMELEN). 701. — P. K, Lvnors: /Substitution velocity in the case of aromatic halogen-nitro- derivatives’. (Communicated by Prof. C. A. Lopry DE Bruyn). 715. — A. Smits: vOn the progressive change of the factor 7 as function of the con- centration”. (Communicated by Prof. H. W. Baknurs RoozEBoom). 717. crecLes (On the pedal) of the point-field in reference to a given triangle. 323. COEFFICIENT of pressure variation of pure hydrogen between 0° and 1009. 299. COHEN (£RNS1). Thermodynamics of standard cells, (IL). 91. (III). 208. — The Enantiotropy of Tin. (V). 93. (VI). 469. — The metastability of the Weston-cadmiumcell and its insuitability as standard of electromotive force. 217.

— Experimental determination of the limiting heat of solution. 327.

— The Weston-cadmiumeell. 380.

— and E. H. Bocuner: Erarp’s Law of solubility. 561.

— and H. Raxen. The solubility of caleiumearbonate in sea-water. 63. CONCENTRATION (On the progressive change of the factor 7 as function of the). 717. CONDENSATION (On the phenomena of) in mixtures in the neighbourhood of the

critical state. 66. CRITICAL STATE (On the phenomena of condensation in mixtures in the neighbourhood of the). 66. — (On pe Huen’s experiments about the). 628.

— (On differences of density in the neighbourhood of the) arising from differences of temperature. 691.

crysTaLs (The formation of mixed) of Thalliumnitrate and Thalliumiodide. 98.

— of bismuth (On the Hall-effect and the resistance of) within and without the magnetic field. 316. 407.

vi CONTENTS,

curvE (Involutions on a) of order four with triple point. 696. curves 4" (On the spacial anharmonic ratio of) of order x in the system Sz with n-dimensions. 235.

— (Eutectic) in systems of three substances of which two are optical antipodes. 463, cyclic MotTIoN (The equation of state and the theory of). (I). 515. (II). 571. (II). 643. cytTisus abAMI (On the development of Buds and Bud-variations in). 365, pensity (On differences of) in the neighbourhood of the critical state arising from

differences of temperature. 691. DILUVIAL erratics. See Errarics. DINITROBENZENES (Review of the results of a comparative study of the three). 375. DuUBOIs (EUG). The amount of the circulation of the Carbonate of Lime and the age of the Earth. (I). 43. (ID. 116. EARTH (The amount of the circulation of the Carbonate of Lime and the age of the).

(1). 48. (IL. 116.

— (The motion of the Pole of the) according to the observations of the last years. 157. ECHINOPSINE, « new crystalline vegetable base. 11.

— (On the physiological action of). 23.

— (On the localisation of). 24.

ELASTIC substances. See SUBSTANCES.

ELECTROMOTIVE FORCE (The metastability of the Weston-cadmiumceell and its insuita- bility as standard of). 217.

EMDEN (J. E. G. VAN). On the durability of the agglutinative substances of the bloodserum, 41.

ENANTIOTROPY (The) of Tin. (V). 93. (VI). 469.

enzYMES (On the influence of nutrition on the secretion of) by Monilia sitophila (Mont.) Sace. 489,

EQUATION of state (The) and the theory of eyclic motion, (D. 515. (IL). 571. (LID). 643.

EQUILIBRIA (Notes on) in ternary systems. 701.

eRkatics (Leperditia baltica His, sp. their identity with Leperditia Kichwaldi Fr. v. Sechm. and their being found in Groningen diluvial). 137.

ERRATIC BLOCKS (On the occurrence of remains of Leperditia grandis Schrenck sp. in the) of the Groningen diluvium. 545.

ERRATUM, 374,

ETARD’'s Law of solubility, 661.

EUTEOCTIC curves, See Curves.

EVERDINGEN JR. (E, VAN). The Hall-eflect and the increase of resistance of bismuth in the magnetic field at very low temperatures. (IL). 177.

— On the Hall-effect and the resistance of erystals of bismuth within and without

the magnetic field. 316. 407,

ExPANsION of a function (On the) in a series of polynomials, 565.

ByYK (6, VAN), The formation of mixed erystals of Thalliumnitrate and Thallium- iodide, 98,

vacton ¢ (On the progressive change of the) as function of the concentration, 717,

PAMADIO stimulation (On the influence upon respiration of the) of nerve tracts passing

through the internal capsula, 68%,

CONTENTS. vit

FoRMAL- (methylene-) compounds (A new kind of) of some oxy-acids. 400.

FRANCHIMONT (a. P. N.) presents a paper ‘of Dr. M. Gresuorr : /Echinopsine, a new crystalline vegetable base”. 11.

— Plumieride and its identity with Agoniadine. 35.

— presents the dissertation of Dr. L. van ScuerPENzeeL: /The action of hydrogen nitrate (real nitric acid) on the three toluic acids and some of their derivatives”. 203.

FREEZING-POINT of solutions (Some observations on the results obtained in the deter- mination of the decrease in vapour-tension and of the lowering of the) which are not very dilute. 507.

FouNcTION (On the expansion of a) in a series of polynomials. 565.

FuNGI (Contributions to the knowledge of some undescribed or imperfectly known). (D. 140. (ID). 230. (ILD. 232. (IV). 386.

Gases (Isothermals of diatomic) and their binary mixtures. 621.

— (Measurements on the magnetic rotation of the plane of polarisation in liquefied) under atmospheric pressure. (1). 70.

GEGENBAUER (t.). On the Mac Manon generalization of the Newron-GiraRD formulae. 347.

Geodesy. J. A. C. OupEMans: ,On the contents of the 6 and last part of the Report Die Triangulation yon Java’. 549.

Geology. Eva. Dusors: /The amount of the circulation of the Carbonate of Lime and the age of the earth’. (Communicated by Prof. J. M. van BEMMELEN). (I). 43. (IL). 116.

-— J. H. Bonnema: vLeperditia baltica His. sp. their identity with Leperditia Eichwaldi Fr. y. Schm. and their being found in Groningen diluvial erratics”. (Communicated by Prof. J. W. Mott). 137.

— J. L. C. ScuRoEDER VAN DER KoLk: The so-called opake minerals in trans mitted light”. 254.

— J. H. Boynema: 7On the occurrence of remains of Leperditia grandis Schrenck sp. in the erratic blocks of the Groningen diluvium”. (Communicated by Prof, J. W. Motu). 545.

GERMINATION of foreign Pollen (Preservatives on the stigma against the). 264.

GLANDULA THYMUS (On the proteids of the). 383.

GRAPHICAL treatment of the transverse plait. 275.

GREsSuOFF (M.), Echinopsine, a new crystalline vegetable base. 11.

HALL-EFFECT (The) and the increase of resistance of bismuth in the magnetic field at very low temperatures. (IL), 177.

— (On the) and the resistance of crystals of bismuth within and without the magnetic field. 316. 407.

HAMBURGER (u. J.), On the resisting power of the red bloodcorpuseles. 76.

— On the permeability of the red bloodeorpuscles for NO,- and SO,-ions. 371.

HARTMAN (CH. M. A.), On the phenomena of condensation in mixtures in the neighbourhood of the critical state. 66.

HEaT of solution (Experimental determination of the limiting). 327.

nEATs of solution (On) in general, that of Cd SO,, °/, H,O in particular, 467.

HEEN’s (DE) (On) experiments about the critical state. 628.

) ; q i]

VIIt GOR PEN TS:

HOFFMANN (c. K.) presents a paper of Dr. J. F. van BemMeven: /Further results of an investigation of the Monotreme-skull”. 130.

HOLLEMAN (a. F.). On the nitration of orthoehloro- and orthobromobenzoic acid. 462.

HOLSBOER (H. B.). On heats of solution in general, that of Cd SQ,, */,; H,O in particular. 467. i

HUBRECHT (A. A. W.) presents a paper of Dr. J. F. van BemMMeELeNn: Third note concerning certain details of the Monotreme-skull”. 495.

HYDROGEN (Coefficient of pressure-variation of pure) between 0° and 100°. 299.

HYDROGEN NITRATE (real nitric acid) (The action of) on the three toluic acids and some of their derivatives. 203.

HYNDMAN (H. H. FRANCIS). See KAMERLINGH OnnzEs (H. H.).

tnDIGO (Further researches on the formation of) from the Woad (Isatis tinctoria). 101.

INTERNAL CAPSULA (On the influence upon respiration of the faradic stimulation of nerye tracts passing through the). 689.

TopivE (Lhe behaviour of mixtures of mercuric-iodide and silver-iodide). 84.

1oxs (On the permeability of the red bloodcorpuscles for NO,- and SO,-). 371.

ISATIS TINCTORIA. See Woap.

ISOTHERMALS of diatomic gases and their binary mixtures. 621.

— (Precise), 421. 481.

KAEMPFERIA Galanga L. (On the crystallised constituent of the essential oil of). 38.

KAMERLINGH ONNES (H.) presents a paper of Dr. Ca. M. A. Hartman: /On the phenomena of condensation in mixtures in the neighbourhood of the critical state”. 66.

— presents a paper of Dr. L, H. Stertsema : Measurements on the magnetic rotation of the plane of polarisation in liquefied gases under atmospheric pressure”. (I). 70.

— presents a paper of Dr. E. van Everpincen Jr: /The Haxt-eftect and the increase of resistance of bismuth in the magnetic field at very low temperatures”. (Il), 177.

— Contributions to the knowledge of vaN per Waats’ p-surface. (I). Graphical treatment of the transverse plait”, 275. (UL). The part of the transverse plait in the neighbourhood of the plaitpoint in KUENEN’s experiments on retrograde con- densation. 289.

— presents a paper of Dr. BE. van Everpincen Jr: »On the Haxt-eflect and the resistance of crystals of bismuth within and without the magnetic field”. 316. 407.

— presents a paper of J, OC. ScuankwuK: /Precise isothermals. I. Measurements and calculations on the corrections of the mercury meniscus with standard mano- meters”, 421, 481.

— On ve Ileey’s experiments about the critical state. 628.

— On differences of density in the neighbourhood of the critical state arising from differences of temperature. 61.

— and M, Bouprtx. On the measurement of very low temperatures. ILI. Coefficient of pressure variation of pure hydrogen between 0° and 100°, 299.

—and H, HH, Paancis ttynpman, Isothermals of diatomic gases and their binary mixtures, 1, Piezometers of variable volume for low temperatures. 621,

KAPTEYN (J, ©). On the luminosity of the fixed stars. 658.

CONTENTS. 1x

KLUYVER (J. c.). On the expansion of a function in a series of polynomials. 565. KOBERT (k.). On the physiological action of Echinopsine. 23. KOLK (J, L. C. SCHROEDER VAN DER). See SCHROEDER VAN DER KOLK (J. L.C.). KUENEN’s experiments (The part of the transverse-plait in the neighbourhood of the plaitpoint in) on retrograde condensation. 289. LANGELAAN (js, w.). On muscle-tone. 248. — On the determination of sensory spinal skinfields in healthy individuals. 251. LEPERDITIA baltica His. sp. their identity with Leperditia Eichwaldi Fr. vy. Schm. and their being found in Groningen diluvial erraties. 137. — grandis Schrenek sp. (On the occurrence of remains of) in the erratic blocks of the Groningen diluvinm. 545. . LIQUID-PHAsEs (On the composition of the vapour-phase in the system : Water-Phenol, with one and with two). 1. LOBRY DE BRUYN (ce. A.). Review of the results of a comparative study of the three dinitrobenzenes. 375. — presents a paper of Dr. J J. Branxsma: vOrganic polysulfides and the poly- sulfides of sodium”. 457. — presents a paper of N. Scuoori: On urea derivatives of sugars”. 459. — presents a paper of Prof. A, F. Hotneman: On the nitration of orthochloro- and orthobromobenzoic acid”. 462. — presents a paper of Dr. P. Kk. Lunors: Substitution velocity in the case of aromatic halogen-nitroderivatives”. 715. — and W. Auserpa vaN Exenstets: ”A new kind of formal- (methylene-) com- pounds of some oxy-acids”. 400. LORENTZ (H. A.). The theory of radiation and the second taw of Thermodynamics. 436. — Bourzmann’s and Wren’s Laws of radiation. 607. LULOFs (P. K.). Substitution velocity in the case of aromatic halogen-nitroderi- vatives. 715. MAC GILLAVRY (TH. H.) presents a paper of Dr. J. E. G. van Empen: »On the durability of the agglutinative substances of the bloodserum”’. 41. MAC MAHON generalization (On the) of the Newron-Grrarp formulae. 347. MAGNETIC FIELD (The Hatt-effect and the increase of resistance of bismuth in the) at very low temperatures, ([L). 177. — (On the Hatt-effect and the resistance of erystals of bismuth within and without the). 316. 407. MAGNETIC ROTATION (Measurements on the) of the plane of polarisation in liquefied gases under atmospheric pressure. (I). 70. MANOMETERS (Measurements and calculations on the corrections of the mercury meniscus with standard). 421. 481. Mathematics. P. H. Scuourr: On the spacial anharmonic ratio of curves 6" of order n in the space Sx with n-dimensions”. 255.

— Jan ve Vrigs: vOn the pedal-circles of the point-field in reference to a given triangle”. 323.

— L. Grcensaver: On the Mac Manon generalization of the Newron-Grrarp formulae”. (Communicated by Prof. JAN pe Vriks). 347.

x €ONTENTS.

Mathematics. J. C. Kuvyver: /On the expansion of a function in a series of polynomials”. 565. — Jan ve Vates: /Involutions on a curve of order four with triple point”. 696. MEASUREMENT (On the) of very low temperatures. 299. MEASUREMENTS and calculations on the corrections of the mercury meniscus with standard manometers. 42]. 481. — on the magnetic rotation of the plane of polarisation in liquefied gases under atmospheric pressure. (I). 70. MENIScUs (Measurements and calculations on the corrections of the mercury) with standard manometers. 421. 481. MERCURIC-iodide. See [ODIDE. METASTABILITY § (The) of the Weston-cadmiumcell and its insuitability as standard of electromotive force. 217. METHOD (A new) for the exact determination of the boiling-point. 86. METHYL-PHENYLAMINOFORMiC ACID, See ACID. METHYLENE-compounds, See Formau- (methylene-) compounds, MICROBES (On different forms of hereditary variation of). 352. MINERALS (The so-called opake) in transmitted light. 254. — (On hardness in) in connection with cleavage. 645. Mineralogy. J. LL. C. ScHrorDER VAN DER KoLk: On hardness in minerals in connection with cleavage”. 655. MIXTURES (lsothermals of diatomic gases and their binary). 621.

— (On the phenomena of condensation in) in the neighbourhood of the critical state. 66,

— (The properties of the pressure-curves for co-existing phases of). 163. — of mercuric-iodide and silver-iodide (The behaviour of). 84.

MOLECULAR attraction. See ATTRACTION.

MOLL (J. w.) presents a paper of J. H. Bonnema: /Leperditia baltica His. sp. their identity with Leperditia Kichwaldi Fr. vy. Schm. and their being found in Groningen diluvial erraties”. 137.

— presents a paper of J. H. Bonnema: /On the occurrence of remains of Leperditia grandis Schrenck sp. in the erratic blocks of the Groningen diluvium”. 545. MONILIA siTOPHILA (Mont.) Sacc. (On the influence of nutrition on the secretion of

enzymes by). 489.

MONOTREME-SKULL (Hurther results of an investigation of the). 180. 3™4 Note, 405.

MUSCLE-TONE (On). 248.

NeRVE tracts (On the influence upon respiration of the faradic stimulation of) passing through the internal capsula. 689.

NEWTON-GIRARD formulae (On the Mac Manon genelarization of the). 347.

NITRIC ACID. See ACID. — See HybDkOGEN NITRATE.

NITRATION (On the) of orthochloro- and orthobromobenzoic acid. 462.

NITRODERIVATIVES (Substitution velocity in the case of aromatic halogen-). 716.

NUTRITION (On the influence of) on the secretion of enzymes by Monilia sitophila (Mont.) Sace. 489.

CONTENTS. XT

OcimMUM BastLicum L. (On the essential oil from), 454. ort (On the essential) from the leaves of Alpinia Malaccensis Rose. 451. — (On the essential) from Ocimum Basilicum L. 454. — of Kaempferia Galanga L, (On the crystallised constituent of the essential). 38. OLIGONITROPHILOUS Bacteria (On). 586. ONNES (A. KAMERLINGH). See Kamersinen Onnes (H.). ORTHOCHLORO- and orthobromobenzoic acid. See Acrp. OUDEMANS (C. A. J. A.). Contributions to the knowledge of some undescribed or imperfectly known fungi. (1). 140. (II). 230. (ILL). 332. (LV). 386. OUDEMANS (J. A. c.). On the contents of the 6th and last part of the Report: w\ie Triangulation von Java’. 549. oxy-acips (A new kind of formal- (methylene-) compounds of some). 400.

PAIN (Curious disturbances of the sensation of) in a case of tabes dorsalis. 253. Pathology. J. E. G. van Emprn: 7On the durability of the agglutinative substances of the bloodserum’’. (Communicated by Prof. Tu. H. Mac Ginpavry). 41.

— H. D. Bererman: /Curious disturbances of the sensation of pain in a case of tabes dorsalis”, (Communicated by Prof. C. WINKLER). 253.

PEKELHAR1NG (Ee. a.). On the proteids of the glandula thymus. 383.

PERMEABILITY (On the) of the red bloodcorpuscles for NO,- and SO,-ions. 371.

PHASES of mixtures (The properties of the pressure-curves for co-existing). 163.

PHENOL (On the composition of the vapour-phase in the system Water-), with one and with two liquid-phases. 1.

Physics. J. D. van per Waaus Jr: /On the relation between radiation and molecular attraction”. 27.

— Ch. M. A. Hartman: On the phenomena of condensation in mixtures in the neighbourhood of the critical state”. (Communicated by Prof. H. Kamertineu Onnzs). 66.

— L. H. Stertsrma: Measurements on the magnetic rotation of the plane of polarisation in liquefied gases under atmospheric pressure”. (I). (Communicated by Prof. H. Kamertineu Onnzs). 70.

— J. D. van per Waats: The properties of the pressure-curves for co-existing phases of mixtures”. 163.

— E. van Everpincen Jr: The Haut-effect and the increase of resistance of bismuth in the magnetic-field at very low temperatures’. (II). (Communicated by Prof. H. KamertineH Onnes). 177.

— H. Kameriinen Onnes: /Contributions to the knowledge of van DER WAALS’ J-surface. I. Graphical treatment of the transverse plait”. 275. I. The part of the transverse-plait in the neighbourhood of the plaitpoint in KUENEN’s experi- ments on retrograde condensation”, 289.

— H. Kameriincao Onnes and M. Boupiy: On the measurement of very low temperatures. ILI. Coefficient of pressure variation of pure hydrogen between 0° and 100°”. 299.

— E. van Everprncen Jr: 7On the Hall-effect and the resistance of crystals of bismuth within and without the magnetic field”. (Communicated by Prof. H.

KamerbineH Onnzs). 316. 407.

XII CONTENTS,

Physics. J. C. Scuatkwwuk: Precise Isothermals. I. Measurements and calculations on the corrections of the mercury meniscus with standard manometers’’. (Communi- cated by Prof. H. Kameriincn Onnes). 421. 481.

—H. A. Lorenz: The theory of radiation and the second law of Thermody- namics”. 436,

— G. Bakker: /Contributions to the theory of elastic substances”. 473.

— J. D. van perk Waais: ,Lhe equation of state and the theory of cyclic motion”. (1). 515. (fH). 571. (III). 643.

— H, A. Lorentz: /BoLtzMann’s and Wren’s Laws of radiation”. 607.

— H. Kamertinen Onnes and H. H. Francis Hynpman: Isothermals of diatomic gases and their binary mixtures, I. Piezometers of variable volume for low tem- peratures”. 621.

— H, Kameruincn Onnus: On pr Heen’s experiments about the critical state”. 628.

— H. KamertincH Onnes: 7On differences of density in the neighbourhood of the critical state arising from differences of temperature”. 691.

Physiology. H. J. Hampurcer: /On the resisting power of the red bloodcorpuscles”. 76. — J. W. Lanceraan: On muscle-tone”. (Communicated by Prof. T. Pace). 248. — J. W. Lancrtaan: vOn the determination of sensory spinal skinfields in healthy

individuals”. (Communicated by Prof. C. Wixxkurr). 251.

— H. J. Hampurcer: On the permeability of the red bloodcorpuscles for NO,- and SO,-ions”. 371.

— C. A. Prexennarine: vOn the proteids of the glandula thymus”. 383.

— J. Branp: /Researches on the secretion and composition of bile in living men’’. (Communicated by Prof. B. J. Srokvis). 584.

— H. D. Beterman: On the influence upon respiration of the faradic stimula- tion of nerve tracts passing through the internal capsula”. (Communicated by Prof. C. WiNKLER). 689.

PIEZOMETERS of variable volume for low temperatures. 621.

PLACE (t.) presents a paper of Dr. J. W. Lancetaan: /On muscle-tone”. 248.

pLaiTpoint (The part of the transverse-plait in the neighbourhood of the) in KUENEN’s

experiments on retrograde condensation. 289.

PLANTS (On the origin of new species of). 245.

PLUMIERIDE and its identity with Agoniadine. 35.

POINT-FIELD (On the pedal circles of the) in reference to a given triangle. 323.

POLARISATION (Measurements on the magnetic rotation of the plane of) in liquefied gases under atmospheric pressure. (I). 70.

pote of the Earth (The motion of the) according to the observations of the last years, 157.

POLLEN (Preservatives on the stigma against the germination of foreign). 264.

POLYNOMIALS (On the expansion of a function in a series of), 565.

POLYSULFIDES (Organic) and the polysulfides of sodium. 457.

POWER (On the resisting) of the red bloodcorpuscles. 76.

PRESSURE-CURVES (Ihe properties of the) for co-existing phases of mixtures. 163.

PRESSURE-VARIATION (Coefficient of) of pure hydrogen between 0° and 100° 299.

proterps (On the) of the glandula thymus. 383.

CONTENTS. XIII

RADIATION (On the relation between) and molecular attraction. 27. — (The theory of) and the second law of Thermodynamics. 436, — (Boirzmann’s and WIeEN’s Laws of). 607. RAKEN (H.). See ConENn (Ernst). RATIo (On the spacial anharmonic) of curves £" of order x in the space Sx with n—dimensions. 255. REINGANUM (m.) and H. Kamerttnen Onnes. The part of the transverse-plait in the neighbourhood of the plaitpoint in KUENEN’s experiments on retrograde condensation. 289.

RESEARCHES on the secretion and composition of bile in living men. 584, RESISTANCE (The Hatt-effect and the increase of) of bismuth in the magnetic field at very low temperatures. (II). 177. — of crystals of bismuth (On the Hatt-effect and the) within and without the magnetic field. 316. 407.

RESISTING Power. See POWER.

RESPIRATION (On the influence upon) of the faradic stimulation of nerve tracts passing through the internal capsula. 689. RETROGRADE condensation (The part of the transverse-plait in the neighbourhood of the plaitpoint in KUENEN’s experiments on). 259. ROMBURGH (P. VAN). On the crystallised constituent of the essential oil of Kaempferia Galanga L. 38. — On the essential oil from the leaves of Alpinia malaccensis Rose. 451, — On the action of nitric acid on the esters of methyl-phenylaminoformic acid. 451. — On the essential oil from Ocimum Basilicum L. 454. ROOZEBOOM (H. W. BAKUUTIS). See Baxuurs Roozesoom (H. W.). SANDE BAKHUYZEN (E. F. VAN DE). The motion of the Pole of the Earth according to the observations of the last years. 157. SANDE BAKHUYZEN (H. G. VAN DE). Report of the committee for the organization of the observations of the solar eclipse on May 18th 1901. 529. SAPROLEGNIACEAE (A pure culture of). 601. SCHALKWIJK (J. c.). Precise isothermals. I. Measurements and calculations on the corrections of the mercury meniscus with standard manometers. 421. 481. SCHERPENZEEL (ut. VAN). The action of hydrogen nitrate (real nitric acid) on the three toluic acids and some of their derivatives. 203. SCHOORL (N.). On urea derivatives of sugars. 459. SCHOUTEN (s. L.). A pure culture of Saprolegniaceae. 601. SCHREINEMAKERS (fF, a. H.). On the composition of the vapour-phase in the system: Water-Phenol, with one and with two liquid-phases. 1. — Notes on Equilibria in ternary systems. 701, SCHROEDER VAN DER KOLK (J. L. c.). The so-called opake minerals in transmitted light. 254. — On hardness in minerals in connection with cleavage. 655. SCHOUTE (P. H.). On the spacial anharmonic ratio of curves 6" of order x in the space Sv with v-dimensions. 255.

XIV CONTENTS,

SEA-waTer (The solubility of calciumearbonate in). 63. SIERTSEMA (L. H.). Measurements on the magnetic rotation of the plane of pola- risation in liquefied gases under atmospheric pressure. (I). 70. SILVER-iodide. See [op1pE. SKINFIELDS (On the determination of sensory spinal) in healthy individuals. 251. smits (a.). A new method for the exact determination of the boiling-point. 86. — On soap-solutions. 133, — Determination of the decrease of vapour-tension of a solution of Na Cl.at higher temperature. 503. — Some observations on the results obtained in the determination of the decrease in vapour-tension and of the lowering of the freezing-point of solutions, which are not very dilute. 507. — On the progressive change of the factor 7 as function of the concentration, 717. soaP-solutions (On). 123. sopium (Organic polysulfides and the polysulfides of). 457. SOLAR ECLIPSE (Report of the committee for the organization of the observations of the) on May 18th 1901. 529. SOLUBILITY (Erarb’s Law of). 561. soLuTION (Experimental determination of the limiting heat of). 327. — of NaCl (Determination of the decrease of vapour-tension of a) at higher tem- perature. 503. — (Heats of). See Heats. soLuTIONs (Some observations on the results obtained in the determination of the decrease in vapour-tension and of the lowering of the freezing-pomt of) which are not very dilute. 507. spacE Sn with n-dimensions (On the spacial anharmonic ratio of curves 6" of order x in the), 255. STANDARD-CELLS (Thermodynamics of). (IL). 91. (III), 208. stars (On the luminosity of the fixed). 658. sTIGMA (Preservatives on the) against the germination of foreign Pollen. 264. sTOKVIS (8. J.) presents a paper of Dr. J. Branp: /Researches on the secretion and composition of bile in living men”. 584. suBSTANCES (On the durability of the agglutinative) of the bloodserum. 41. — (Contribution to the theory of elastic). 473. suGARS (On urea derivatives of). 459. y-surFacE (Contributions to the knowledge of vAN per Waals’). 275. sysTEM (Bi,O,—N.,O;—H;0) (On the). 196. systeMs (Notes on equilibria in ternary). 701. papus dorsalis (Curious disturbances of the sensation of pain in a case of). 253. TEMPERATURE (Determination of the decrease of vapour-tension of a solution of Nal at higher). 503. — (On differences of density in the neighbourhood of the critical state arising from differences of). 691. Temperatures (‘The Hatt-effect and the increase of resistance of bismuth in the magnetic field at very low). (IL), 177.

OVOoN= TB oN DS. XIV

TEMPERATURES (On the measurement of very low). 299.

— (Piezometers of variable volume for low). 621. TERNARY systems. See SysTEMs. THALLIUMNITRATE and Thalliumiodide (The formation of mixed crystals of). 98. THEORY of radiation (The) and the second law of Thermodynamics. 436.

— of elastic substances (Contribution to the). 473.

— of cyclic motion (The equation of state and the). (D. 515. ({1). 571. (ID). 643, THERMODYNAMICS of standard-cells. (II). 91. (IIT). 208.

— (The theory of radiation and the second law of). 436. TIN (The Enantiotropy of). (V). 93. (VI). 469.

ToLuic acrps (The action of hydrogen nitrate (real nitric acid) on the three) and some of their derivatives. 203.

TRANSVERSE-PLAIT (Graphical treatment of the). 275.

— (The part of the) in the neighbourhood of the plaitpoint in KUENEN’s experiments on retrograde condensation. 289.

TRIANGLE (On the pedal circles of the point-field in reference to a given). 523.

TRIANGULATION (Die) von Java (On the contents of the 6th and last part of the Report). 549.

TRIPLE POINT (Involutions on a curve of order four with). 696.°

UREA derivatives (On) of sugars. 459.

VAPOUR-PHASE (On the composition of the) in the system: Water-Phenol, with one and with two liquid-phases. 1.

VAPOUR-TENSION (Determination of the decrease of) of a solution of NaCl at higher temperature. 503.

— (Some observations on the results obtained in the determination of the decrease in) and of the lowering of the freezing-point of solutions, which are not very dilute. 507.

VARIATION (On different forms of hereditary) of microbes. 352.

veELocitTy (Substitution) in the case of aromatic halogen-nitroderivatives. 715. VERSCHAFFELT (E.). On the localisation of Echinopsine. 24.

VRIES (HUGO DB). On the origin of new species of plants. 245.

— presents a paper of Dr. W. Burck: /Preservatives on the stigma against the germination of foreign Pollen”. 264.

VRIES (JAN DE). On the pedal circles of the point-field in reference to a given triangle. 323.

— presents a paper of Prof. L. GrcenBaurr: ”On the Mac Manon generalization of the Newron-Grirarp formulae”. 347.

— Involutions on a curve of order four with triple point. 696.

WAALS (VAN DER) w surface (Contributions to the knowledge of). 275. WAALS (J. D. VAN DER). The properties of the pressure-curves for co-existing phases of mixtures. 163, — The equation of state and the theory of cyclic motion. (1). 515. (IT). 571. ({1]). 643, WAALS JR (J. D. VAN DER). On the relation between radiation and molecular attraction. 27.

XVI CONTENT &

WATER (On the system: bismuthnitrate and). 196, WATER-PHENOL (On the composition of the vapour-phase in the system), with one and with two liquid-phases. 1. WENT (fF. A. F. C.). On the influence of nutrition on the secretion of Enzymes by Monilia sitophila (Mont.) Sacc. 489. — presents a paper of S. L. Scnouren: 7A pure culture of Saprolegniaceae”. 601. weEsTon-Cadmiumeell. See CaDMIUMCELL. — (The). 380. WIEN’s Laws of Radiation (BoutTzMaNnn’s and). 607. WIND (c. u.). On the irregularities of the cadmium standard cell. 595. WINKLER (c.) presents a paper of Dr. J. W. Lanceraan: On the determination of sensory spinal skinfields in healthy individuals”. 251. — presents a paper of H. D. Brryerman: Curious disturbances of the sensation of pain in a case of tabes dorsalis”. 253. — presents a paper of H. D. BeryermaN: On the influence upon respiration ot the faradic stimulation of nerve tracts passing through the internal capsula’’. 689. woab (Isatis tinctoria) (Further researches on the formation of Indigo from the). 161. Zoology. J. F. van BemMe en: /Further results of an investigation of the Monotreme- skull”. (Communicated by Prof. C. K. Horratany). 139. — J. F. van BemMe en: Third note concerning certain details of the Monotreme- skull”. (Communicated by Prof. A. A. W. Husrecut). 405.

KONINKLIJKE AKADEMIE VAN WETENSCHAPPEN TE AMSTERDAM.

PROCEEDINGS OF THE MEETING

of Saturday May 26, 1900.

DOG

(Translated from: Verslag van de gewone vergadering der Wis- en Natuurkundige Afdeeling van Zaterdag 26 Mei 1900 Dl. IX).

Contents: “On the composition of the vapour-phase in the system: Water-Phenol, with one or with two liquidphases.” By Dr. F. A. H. Scurrinemakers (Communicated by Prof. J. M. van BemMeven), p. 2. —“Echinopsine, a new crystalline vegetable base.” By Dr. M. Gresnorr (Communicated by Prof. A. P. N. Francuimonr), p. 11. — “On the relation between radiation and molecular attraction”. By J. D. van DER Waats Jr. (Communicated by Prof. J. D. vax per WaAAts), p. 27. — “Plumieride and its identity with Agoniadine”. By Prof. A. P. N.@rancurmonr, p.35. — “On the crystallised constituent of the essential oil of Kaempferia Galanga L.”. By Dr. P. van Romeureu, p. 38.—“On the durability of the agglutinative substances of the bloodserum”. By Dr. J. E. G.van EmpEn (Communicated by Prof. Tu. H. Mac Giiiavry), p. 41. —“The amount of the circulation of the carbonate of lime and the age of the Earth”. I. By Prof. Eve. Dusois (Communicated by Prof. J. M. vAN BemMELEN), p. 43. —‘“The solu- bility of Caleium Carbonate in Sea-water”. By Dr. Ernst Comen and H. RakEN (Communicated by Prof. H. W. Bakauis Roozesoom), p. 63. — “On the pheno- mena of condensation in mixtures in the neighbourhood of the critical state”. By Dr. Cu. M. A. Harrman (Communicated by Prof. H. KameRLInGH Onnes), p. 66.— “Measurements on the magnetic rotation of the plane of polarisation in liquefied gases under atmospheric pressure’. By Dr. L. H. Srertsema (Communicated by

Prof. H. Kameriinca Onnes), p. 70. (With one plate). — “A new method for the exact determination of the elevation of the Boiling-point”. By Dr. A. Smirs (Com- municated by Prof. H. W. Bakuurs Roozesoom), p. 74. — “Thermodynamics of

Standard Cells” (2nd part). By Dr. Ernst Consen (Communicated by Prof. H. W. Bakuuis RoozEsoom), p. 74. — “On the Enantiotropy of Tin”. V. By Dr. Ernst Conen (Communicated by Prof. H. W. Bakuuris Roozesoom), p. 74. — “The formation of mixture-crystals of Thalliumnitrate and Thalliumiodide”. By Dr. C. vax Eyk (Coin- municated by Prof. H. W. Bakuurs RoozEBoom), p. 74.

The following papers were read:

Chemistry. — ‘On the composition of the vapour-phase in the system Water-Phenol, with one and with two liquid-phases”. By Dr. F. A. H. Scuremnemakers (Communicated by Prof. J. M. vAN BEMMELEN).

(Read April 21, 1900.)

1. The apparatus.

To determine the composition of the vapour phases the apparatus

shown in fig. 1 was used. The flash A into which the mixture to 1 Proceedings Royal Acad. Amsterdam. Vol. III.

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be investigated was introduced is closed by means of a ground in tube B containing a little mercury in which the thermometer was placed.

Sig I.

The tube C is connected by means of a ground joint with the condenser and through this with a space of about 18 litres capac- ity, in which the pressure can be altered as desired by means of a pump; the pressure in this space was determined by means of an open mercury-manometer.

The flash A is further connected by means of the tube D with the little flask # which is connected by a ground joint with D. This flask may further be connected by means of / with the outer air, or with the space with which A is always connected or with another space in which the pressure may be regulated at will. In order to determine the vapour tension at a certain temperature, the bath was raised a few degrees above the desired temperature and the pressure in the space which is connected with A, afterwards altered, until the liquid contained in A began to boil. By a further slow change of the pressure, the boiling point of the liquid was brought to the desired temperature and read off on the thermometer placed in B.

The vapour evolved in 4A ascends through C into the condenser,

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where it is condensed and returned to A; it cannot pass into the space , because the tube P contains a little mercury between the two small bulbs, and the space Z is connected with the same space as 4.

To determine the composition of the vapour phase, some vapour from A was transferred to the flask 2, which was placed in a freezing mixture in order to completely condense the vapour. In order to transfer the vapour from A to £ the latter was connected, by means of the tube F, with a space in which the pressure was a little less than that in the space connected with A. The vapour evolved in A now bubbles through the mercury in the tube D; the rapidity with which this takes place may be regulated at will by making the difference in pressure between A and /’ greater or smal- ler. By means of this arrangement, it is not only possible to regu- late the rate at which the vapour is conveyed from A to £, but also to stop or to restart the transference at will, the temperature and pressure in A remaining unchanged. Because the bath has alwaysa higher temperature than the liquid and vapour in 4, no condensation can take place in that part of the tube Y which is immersed in the bath, but condensation may occur in the part of the tube which is outside the bath. To prevent condensation at @ this part of the tube was maintained at a higher temperature by means of a small flame; the vapour which condensed in the further end of D, was transferred to £ by heating after the distillation was ended.

The composition of the liquid remaining in 4A was, of course, altered by the removal of vapour; as, however a quantity of 100— 200 grams was introduced into A and only 5—10 grams of liquid condensed in £, the change in A was as arule comparatively smal), unless the vapour- and liquid-phases differed very much in compo- sition. In such cases I give the composition of the liquid-phase both at the beginning and the end.

During the transfer of vapour from 4 to Z, vapour was continually rising into the condenser where it was condensed. ‘This condensed liquid, the composition of which was, of course, in general different from that of the liquid in A, gave off a different vapour when flowing down the sides and so caused an error. As a rule, however, this error will doubtless be small. Some determinations have been repeated without admitting any vapour into the condenser during the transfer from 4 to £. For this purpose a little apparatus was used by means of which the tube C could be closed and reopened below the level of the bath. The use of this apparatus, however, gave rise to many difficulties and it was therefore only used a few times.

As experience showed, the determinations of the vapour tension 1*

Cs)

are not quite correct but may be wrong to the extent of a few m.m.; this was found by repeating several times the determination of the vapour-tension of pure water or of a three-phase system in the same apparatus at the same temperature and with the same thermometer, when the determinations sometimes differed among themselves to the extent of 2 or 3 m.m. The liquid collected in the flask EH was at the end of the operation weighed and analysed. In the system Water- Phenol, the phenol was estimated by the method of KoppEscHAaR, i. e. by titration with a solution of K Br and K Br Og.

Il. The three-phase system.

In the system: Water-Phenol, three phases can be in equilibrium with each other between the transition-temperature (about 1°5) and the critical temperature (about 68°), namely two liquid-phases and the vapour. The composition of the two liquid-phases, which may be in equilibrium with each other at the different temperatures, has already been investigated several times, among others, by ALEXEJEFF ') and V. Rotnumunp’); I have now determined the composition of the vapour-phase in the way described.

In table I 7 stands for temperature; P for the pressure of the three-phase system in m.m.; Z, Ly and Z, for the composition of the three phases, L,; and Ly for those of the two liquids and L, for that of the vapour. The composition is expressed in percentage by weight of phenol in the mixture of phenol and water.

TABLE I.

iE P Di Ts io. 29.°8 29 8 70 5.96 38.°2 48 9.5 67 6.98 42.°4 62 10 66 6.91 50.°3 94 12 63 7.28 56.°5 126 14.5 60 7.83 60.°1 150 17 57 8.06 64.°4 182 22.5 48 8.66

The composition of the three phases is shown graphically in figure 2; the temperature is measured along the horizontal axis, the pressure along the vertical axis. The lines Z, and ZL, represent

1) Wied. Ann. 28. 305. *) Zeitschr. f. Ph. Ch. 26. 488,

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the two liquid-phases, the line Z, the vapour-phase. It will be seen from the figure, that the two liquid-phases 2, and ZL, gradually approach the same composition as the temperature rises, and that at 68° they become identical at a point & which indicates about 34 pCt. of phenol. The line Z,, which shows the vapour phases, which may be in equilibrium with both the liquid-phases, lies entirely below the line Z,. The vapour-phase, therefore contains less phenol than occurs in either of the other liquid-phases.

If we call Z,, which contains the most water, the aqueous, and ZI, which contains the most phenol, the phenol-layer, then the vapour contains still less phenol than the aqueous layer.

If a mixture of two liquid-phases of water and phenol is distilled at a constant temperature, say 56°.5, then according to the preceding table the vapour pressure is 126 m.m.; the aqueous layer then contains 14,5 pCt. of phenol, the phenol-layer on the other hand 60 pCt., whilst the vapour only contains 7,83 pCt. of phenol. The aqueous layer has, therefore, a composition between that of the vapour and the phenol-layer; on distillation the aqueous layer will be resolved into the phenol-layer and the vapour, its volume decreas- ing continually until finally only the phenol-layer remains in the retort. If now the distillation is pushed further at constant 7, the pressure cannot longer remain constant, but it must fall as there are now only two phases remaining instead of three. I will revert to this matter presently.

The vapour-curve J, has in this system, a position owtside the two liquid-curves L, and L,. In other systems it may, however, be situated between them; this is for instance the case with the system Water-Aniline which I will mention later on.

It is plain that the different position of branch L, may give rise to other phenomena during the distillation of two liquid phases. This will be discussed subsequently.

In Figure 2, the pressure has not been included ; this might be done by introducing

1004

a third axis perpendicular on é the plane of the drawing and % marking on this the pressure.

The lines LZ, Lg and L, then no longer lies in the plane of the drawing, but in space, in such a way that their three projections on the plane P—'l’ form a curved line,

(Te Sig. IL.

(6)

This line on the plane P—T shows the relation between the temperature and the pressure of the threesphase system. It is, according to table 1, a line which rises with the temperature.

Ill. The two-phase system.

The different two-phase systems which may appear in a binary system, leaving solid phases out of account, are:

1st The system of two liquid-phases.

2nd The system of a liquid with vapour.

The first system has been investigated by VAN DER LEE!); he determined the influence of the increase in pressure on the lines I, and Lz, and found it to be very small.

I have now examined the second systein, mainly in order to discover the connection between the composition of the liquid and the vapour. This may be done in two widely different ways; first the boiling-points and the compositions of the vapours of liquids of different composition may be determined at a constant pressure ; secondly the vapour-pressure and composition may be determined at a constant temperature. I have chosen the last method at the temperatures 56°3, 75° and 90°. The first temperature is situated below the critical point; two liquid phases therefore make their appearance; at the two other temperatures this is not the case.

The following table contains the determinations at 56°.3.

TABLE 2.

No, L D P

1 0 pCt. 0 p(t. 125 mm. 2 2.0 2.55 125 i) 5.58 5.49 127 4 7.42 6.57 126.5 5 10.88 7.42 127 6 14.5—60 7.83 126 7 69.2 { 9.98 124 7e 76.7 yes 122 Bb 80 34 { 11.98 118 8e 88.06 le sem 102

hh . . . . .

The percentage of phenol in the liquid is given under L; the composition of the vapour under D, and the vapour pressure under P.

Determination N°. 6 relates to the ¢wo liquid-phases which may

') Dissertation. Amsterdam.

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be in equilibrium with each other at 56°.3, one of which contains 14.5 pCt., the other 60 pCt. of phenol.

Determination N°. 7 is entered under 7> and 7° ; 7> gives the initial, 7° the final concentration of the liquid. As will be seen, these differ by 7.5 pCt., whilst the vapour differs immensely in composition from the liquid.

The same applies to determination 8.

As will be seen from the table, a liquid containing about 5.5 pCt. op phenol yields a same composition. Liquids containing less than

5 pCt. of phenol yield a vapour containing more phenol than the ae liquids containing more phenol, BOwercr) yield a vapour con- taining less phenol.

Table 3 gives the determination at 75°.

TABLE 3. No. ih D P 1 0 0 299 2 2.43 3.44 293 3 4.15 5.21 293 4 7.51 7.41 294 5 16.82 9.11 294 6b 22.53 294 Ge 24,18 asl 294 7b 44.44 eo 294 7° 49.2 jee 294

gb 60.47 | 292-293

ge baer os? e289 gb 76.7 280

i

ge 82.4 yteeRo 259 10> 88.06 | 218 10° Gi, =p ane 177

In determination N° 4, the vapour and liquid have again about the same composition; with a percentage of 7.2 of phenol they are identical.

If therefore a liquid containing less than 7.2 pCt. of phenol is distilled at 75°, the vapour contains more phenol than the liquid; the reverse is the case if the liquid contains more than 7.2 pCt. of phenol.

The determinations at 90° are given in table 4.

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TABLE 4. N°, L D P 1 0 0 525 mM. 2 2.36 3.64 528 5 7.00 7.69 531 4 8.29 8.30 531 5 9.74 8.96 530 6b 172. { 530 6: Tipe wei ee 530 7 ube woe 530 Ze Alipay ate 530 gb 42.2 | 530 se figy pba 530 b KES ns 9 pad \ 11.24 530 ge 58.0 | 530

As shown in this table, the liquid which at this temperature is in equilibrium with a vapour of the same composition contains about 8.29 pCt. of phenol.

The results shown in the first three tables may be represented graphically in different ways.

I will here, however, make use of only one of these, namely that showing the composition of the vapour-phase as a function of the liquid. The vapour-pressure is thus not considered.

Figure 3 is a graphical repre- — 100722. 8 sentation of this kind; the concentration of the liquid is measured along the horizontal axis, that of the vapour (in percentage of phenol) along the vertical axis.

If we draw the line AB through the square, the points

or on it represent liquids whose A 0% aE Zoxe,. Vapour has the same composi- Sig ADS tion. If a point is situated to

the left of 4B, the vapour con-

tains more phenol than the liquid; if to the right it contains less phenol.

From the drawing it is seen that at each of the three temperatures,

a liquid containing a small quantity of phenol yields a vapour con-

taining more, and one containing much phenol yields a vapour con- taining less phenol than itself.

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The point of intersection of a curve with AB represents a liquid which is in equilibrium with a vapour of its own composition. The proportion of phenol in this liquid increases with the temperature. This liquid must have a maximum or a minimum vapour pressure ; in our case a maximum one.

In our ease, according to table 2, the maximum must be at N°. 3 namely 127 m.m.; in No. 4 the vapour-pressure is certainly not quite accurate, as N°. 5 again indicates 127 m.m. The deviation is, however, far within the experimental error which may amount to several mm. That, in figure 3, the line of 56.3° ends, at least experimentally, in the points Z, and Z, is clear, because L; and Lg indicate the composition of the two liquid-phases which are in equilibrium with the vapour. If, therefore, water and phenol are brought together in such a proportion, that the mixture is represented by a point situated between 2, and Ly, this will break up at 56°3 into the two liquid-phases £, and Zy and vapour, the concentration of which is indicated by the ordinate of one of these points.

In the two other curves the straight line Ly 2, does not occur; they belong to temperatures above the critical point. They, however, present the peculiarity, that they are almost horizontal for a con- siderable distance; or in other words —as may also be seen from the tables 3 and 4—-when the liquid has reached a certain percentage of phenol the composition of the vapour is but little affected even by considerable variations in the amount of phenol in the liquid. According to table 3, the vapour at 75°0 only changes from 9.11 to 10.43 pCt. of phenol, when the liquid changes from 16.82 to 65.75 pCt. With a still larger percentage of phenol in the liquid the amount of phenol in the vapour increases more rapidly, finally increasing very fast indeed, since all the lines in figure 3 must terminate at B.

Not only the amount of phenol contained in the vapour, but also the vapour-pressure alters but little, when the composition of the liquid varies between very wide limits.

In table 3 the maximum of vapour-pressure must lie between the two determinations 3 and 4 and very close to N°. 4. In determi- nations 4, 5, 6 and 7, the vapour pressure is constant at 294 m.m. ; theoretically this is, of course, impossible, but experimentally the differences may fall quite within the limits of experimental errors.

Van DER Lee has also measured the vapour pressure at 75°; he also finds a vapour-pressure of 294 mm. when working with a liquid of widely varying concentration. His other determinations agree fairly well with my own; only liquids containing a very large amount

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of phenol show differences. As I have now determined the compo- sition of liquid and vapour, it is possible to test the observations by means of the approximately accurate formula of VAN DER WAALS:

dP _ P («a— 2) dq ta(l — aa) ~

The best way would be to take the values of zg and P from the dP ‘ determinations as also the values of rae and then to caiculate a rd by means of the formula and compare this value with the experi-

cannot accurately be de-

d mental result. In our case, however, a axd

duced from the experiments, as / does not change or very little between very wide limits.

dP I have therefore, followed a different plan and calculated as

by means of the experimental values of P, xq and «a, from the formula. For this purpose let us take the determinations at 75° (table 3) and recalculate everything in molecules; let us then take the mean of the initial and final compositions and pressures in exper- iments 7, 8, 9 and 10. We then obtain :

TABLE 5. dP

No x1 Ld xg—al

dad 1 0 0 0 289 2 0.0047 0.0067 +0.0020 293 + 88 3 0.0082 0.0104 +0.0022 293 + 62 4 OL015 3 mem OLOilte —0.0002 294 — 3 5 0.0372 0.0188 —0.0184 294 — 294 6 0.0551 0.0193 —0.0358 294 — 556 7 0.1446 0.0204 —0.1242 294 —1825 8 0.2477 0.0218 —0.2259 291 —3083 9 0.4296 0.0269 —0.4027 270 —4154 10 0.6322 0.0493 —0.5829 197 —2449

From the values of in the preceding table I have calculated

akd the values of A P for each pair of successive observations. iad pa ; dP Considering for example observations 2 and 3, the value of aes wd

may be regarded as the mean of the values found in the two exper-

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“

iments, 1. €. =75; the value of A P between observations

2 and 3 is therefore,

AP=A 2a = = (0.0104—0.0067) X 75 = 0.35. Ld

dP : The values of a and A P thus obtained are given in table 6; avd

also, for comparison, the values of A P obtained by direct experiment.

TABLE 6. , dP Between observations aes A P ealeulated A FP found No. 2 and No. 3 75 0.3 m.M. 0 m.M. 3 > 4 30 0.1 1 ARE SUD — 149 — 0.5 0 be6 — 425 — 0.2 0 6.2% 1190 — 1:3 : 0 fis — 2454 — 3.4 — 3 Ses 9 — 3618 — 18.5 — 21 9 »10 — 3302 — 73.9 — 73

As may be seen from the table, AP calculated and A P found agree satisfactorily; the difference are smaller than the experimental errors which may amount to several m.ms.

Chemistry. — ‘“Kchinopsine, a new crystalline vegetable base’’. By Dr. M. GresHorr (Communicated by Prof. A. P. N.

FRANCHIMONT). (Read April 21, 1900).

Of late years alkaloids have been discovered in plantfamilies which, previously, had been made but little the subject of phyto-chemical studies, and in which, at any rate, no vegetable bases had been found or even suspected. So, for instance, in the large family of the Compositae, which comprises about one-tenth part of all the phanerogamia, with more than 800 genera.

The writer has been engaged for many years in the systematic study of alkaloidal distribution in plants, also in this family,!) and

1) Compare: On the distribution of alkaloids in the family of the Compositae. Ned. Tijdschr. vy. Pharm., Mei 1990, blz. 137. In this article 50 alkaloid-containing genera are summarised, mostly the result of my own investigations.

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has now the opportunity to present the meeting with at least one of his new compositae-alkaloids in a pure condition, and to give a

description of the same. First of all, some particulars about the botanical origin.

The genus Echinops L. (= Echinanthus Nucx., Echinopus Tourn., Sphaero cephalus 1.) belongs to the division Twbuliflorae-Cynareae of the Compositae. These Cynareae are divided into four groups: Echinops, Carlina, Carduus and Centaurea, all plants popularly known as thistles; some are characterised, from a chemical standpoint, by containing alkaloids, glucosides, bitter principles and pigments; a few yield hydrocyanic acid.

The group Echinops only contains this genus itself, and Acantholepis orien- talis Luss., a plant from the steppes of Central-Asia. Echinops numbers about 60 species, also mostly Central-Asiatic herbs with alternate, frequently thorned leaves, and all species characterised by having capitula. To the West, the Echinops territory extents over the whole of the South of Europe and the coasts of the Mediterranean, to the East as far as Japan; some species are also natives of tropical Africa. In Germany, &. sphaerocephalus L. grows wild; no species is found wild in Holland. In that country various kinds are, however, cultivated as ornamental plants, on account of the robust stature and the beautiful large flower heads from which the genus derives its name of “ballthistle’” (the latin name is composed of echinus, hedgehog and ops, eye or appearance). The flowers are sometimes light blue #. Ritro L., or dark blue £. bannaticus Rocu. The genus is divided by botanists into 7 sections; compare ENGLER u. PrantL, Natiirliche Pflanzenfamilien IV, 5, p. 313. The species are mostly described in Borsster’s Flora orientalis and also by Bunes, Bull. de l' Académie de St. Pétersbourg VI, 390. My investigation extents over 15 species from different sections 1) which all were found to contain echinopsine, so that there is reason to believe that the presence of this alkaloid is a general characteristic of the Echinops-species.

On the use of Echinops in popular medicine and in toxicology, a question revived by the discovery of the powerful Echinopsine, not much information is at my disposal. Different species, such as #. Ritro L., dahuricus Fiscu.,

1) This is perhaps the proper place to state the source of the important material of my investigation and to thank those who provided me with the same. From the botan- ical garden at Leiden, I received through the care of Mr. E. Tu. Wirre, hortulanus, EL. Ritro L. and #. niveus Wau. Of the first plant, the firm Haace u. Scumopr at Erfurt provided me with the 10 kilograms fruits, which have served for the preparation of a larger quantity of echinopsine, than the supply from the botanical garden allowed. I also got from the sume source JZ. sphaerocephalus L., E. ewaltatus Scuran., EB. paniculatus Jacg. and £. syriacus Borss. On a holiday tour in Sweden in Aug. 1899 I noticed in the excellently kept botanical garden of Lund and Upsala some other varieties cultivated there. In Lund, I collected leaves of EH. dahuricus Fiscu., EB. bannaticus Rocu., L. platylepis Travrv. and EL. microcephalus Supru.; afterwards I received from there seed of #. globifer Janka and of another species which accor- ding to Dr. Sv. Murpeck was, probably, ¥. commutatus Jur. From Lund, the hortulanus Mr. Fr. Perrerson forwarded me beautiful material from 2. viscosus DC., FE. humilis Bres. and L, elatus Bune.

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sphaerocephalus L., are used in East-Russia and Siberia as diaphoretica and diuretica, are also applied in skin diseases. In olden times, the “Herba echinopsidis’ was also used in Europe for treating gravel and stone. To Dr. G. van Vuoren of Leiden I am indebted for a note on the use of this genus by the Arabs. Ipny Wauscuia states in his treatise: De Venenis (cod. Leiden) the following particulars about a plant which he calls “Djirdama’’:

“Djirdama grows at Djukha and at Schafiatha (in Babylonia), and is a powerful poison which kills quickly. It is a tall plant with small leaves, its stem attains the height of a meter. It has a white roselike flower and its taste is even more pungent than that of mustard. A person who has had 2—2,5 drachms of the pulverized plant administred in his food feels a violent itching on the surface of his body and a twisting and pains in the throat and the stomach and a violent burning, so that he often undresses and sits down naked. A weight of two “daniq’s” administred in a beverage to pregnant women causes abortion, and a little of the powder rubbed on the skin causes burning and inflammation.”

It is questionable whether this plant is really meant for an Echinops, as the description corresponds more with that of a pungent crucifer. The name, however, agrees with that of Forskani, Flora aegyptiaco-arabica; but it must not be forgotten that ForSKAHL’s names are of modern times, whilst those of Ipy WauscuyA date from about 800—900. It is, however, true that Echinops has indeed been proved to contain a rapidly killing poison, while if the last line of Isy Wauscuia is intended for the pappus, this is also in complete accordance with the facts that it burns on the skin exactly like itchpowder. (Mucuna.)

A notice in the Pharmacographia Indica seems important, that Echi- nops echinatus DC. is an Indian medicinal plant, called in sanskrit “Utati” and sold in the bazaars as “Utkatara”. The root is bitter and serves as a tonic and diuretic. I may not, however, omit to state that Prof. Dr. H. Kern of Leiden does not believe Utati to be a sanskrit word and said that Echinops is not to be found in literature on ancient Indian medicine. Messrs. D. Hooper and G. Warr of Calcutta, coeditors of the said Pharmacographia, could not as yet give me further particulars on the subject of Utati, but they have promised to order material of this drug for me from Mysore, to ascertain whether the action is due to echinopsine.

For the preparation of Kchinopsine chiefly use has been made of the above mentioned fruits of Hchinops Ritro L., collected for this purpose by Mess's. HaaGe and Scumipt of Erfurt. The first difficulty experienced with this material was its unusual bulk, which excluded the use of extraction-apparatus of ordinary size. Fully two-thirds of it was a straw-like chaff, a stiff tile-like involuerum, which could only be separated with very great difficulty from the fruit proper. A great deal of trouble was caused by the sharp hairs on the fruit, acting on the skin like itchpowder; by rubbing the fingers with oil this could be somewhat guarded against. The fruits yield */3 of seed and '/; of chaff, but the commercial article consists to the extent

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of one-half of empty fruits. The hard exterior (yielding 5,4 pCt. of ash) does not contain alkaloid, but yields a dark colored extract which impedes the purification of the alkaloid contained in the fruits. An aqueous decoction of the fruits tastes bitter yet at 1 : 3000—4000, but that of the involucrum is tasteless. It is, therefore, advisable to remove the involucra in order to obtain a cleaner and less bulky material, but this end cannot be attained either by crushing and grind- ing, or by sifting; the only way is by peeling the fruits by hand, but this is very tedious work. Under those circumstances, I have called in the aid of the governor of the penitentiary at Haarlem where this labour of separating the chaff has been performed by convicts. One kilogram crude material contains 36000 fruits and measures 10 dM°.

The /pvrified material (32 pCt. by weight of the original) was passed through a sieve, to remove the hairs, ground next and again sifted to retain pieces of the fruit-shell. The powdered seed boiled with 10 times its weight of alcohol of 95 pCt. yielded at the first extraction 19,2 and at the second 4 pCt. of extract, total 23,2 pCt. which high percentage is caused by the fatty oil from the seeds ‘which has dissolved in the aleohol. The material was, therefore, first deprived of its oil by extraction with below 50° rectified petroleum ether, which does not dissolve any alkaloid. The powder may also be moistened with an equal weight of ether and then strongly pressed; nearly all the oil is thus removed with the ether. This seedeake was then dried, again pulverized and now percolated to exhaustion with alcohol of 95 pCt. mixed with 3 pCt. of acetic acid. A good yield is also obtained by boiling a few times with alcohol containing acetic acid and pressing warm each time. Of the straw-yellow tincture the alcohol was distilled off. The remnants of this extraction were only bitter at 1 : 150, being "a9 to Moy of the original bitterness. The alcoholic extract had a peculiar ozonelike odour; it was taken up with water and filtered; remained on the filter a little of a not-bitter resin, but the filtrate was inten- sely bitter. This was once more shaken out with petroleum ether, a large quantity of chloroform added, the acid nearly neutralized with sodium carbonate and the whole thoroughly shaken, after the addition of an aqueous solution of caustic potash, slightly in excess. The extraction with chloroform was repeated three times; all the alkaloid goes into the solvents; after distilling off the chloroform, it remains as a light-yellow crystalline mass which dissolves readily in alcohol; the solution is strongly green fluorescent. This solution is decolorized by animal charcoal, but it retains its fluorescence, which

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property is shared by the crystals. There is, however, a liquid extremely well adapted to complete the purification of the crystalline vegetable base present in this complex; it is pure benzene. This readily dissolves the alkaloid by warming, but on cooling off separates practically all out, leaving the fluorescent admixture in solution.

In this manner, by repeated crystallisation until a substance of constant melting point is obtained and also by the judicious use of animal charcoal, a pure and unmixed chemical body is obtained, Echinopsine. This substance may also be obtained in an equally pure state by a repeated crystallisation from boiling water.

In this way 0,5 pCt. of Echinopsine was obtained from the chaff-deprived fruits of E. Ritro; about equally large is the yield of KEchinopsine, from the fruits of other species, analysed by me, such as FH. bannaticus, exaltatus, globifer, niveus, paniculatus , sphaerocephalus, syriacus, viscosus; the yield of Echinopsine from select material of EH. humilis and elongatus was considerably higher; from the first named species it amounted to 1,20 pCt. (!), the other yielded 0,84 pCt. Material received from Erfurt in February 1900 also yielded quite 0,8 pCt. of Echinopsine and in addition 0,1 pCt. of Echinops-fluorescine and 0,15 pCt. of Echinopseine. The amount of alkaloid in the leaves of E. ban- naticus, dahuricus, nivalis, platylepis, which like those of EF. Ritro hardly taste bitter, does not exceed 0,01 pCt. in the fresh or 0,04 pCt. in the dry material. It is considerably higher in the leaves of E. microcephalus, viscosus and globifer, which are all per- ceptibly bitter. From the fresh roots of EZ. Ritro about 0,1 pCt. of Echinopsine may be prepared.

Echinopsine obtained by this process erystallises in thin colourless needles of several cM. in length, forming feathery groups. As has already been shown, it possesses the general properties of an alkaloid ; it contains nitrogen, and leaves no ash. It isa weak base; the crystals when pressed between moist red litmus paper do not colour this blue. The melting point is exactly 152° C. When heated higher Echinopsine remains unaltered for a long time, then decomposes and burns with a sooty flame.

Kchinopsine dissolves 1:60 in water at 15°; in boiling water it dissolves very readily 1 : 6. The alkaloid practically all separates from the saturated solution on cooling, first anhydrous; the fluid then solidifies to a snow-white mass liquifying again upon the addition of hydrochloric acid. Kehinopsine dissolved in water shows very beautifully the phenomenon of supersaturation; the introduction of a minute crystal into the solution soon causes an abundant

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separation of the alkaloid. On slow evaporation, Echinopsine may be obtained in large transparent hydrated crystals; these become opaque when heated with water, tefore dissolving, owing to loss of water of crystallisation.

Echinopsine is easily soluble in methyl-, ethyl- and amyl-alcohol, not so easily in carbon disulphide, insoluble in petroleum ether. The base is soluble in ethyl ether when freshly precipitated, but when crystallised it requires about 600 parts of that solvent at 15°; this is the reason why ethyl ether is not suitable as an extraction liquid for Echinopsine. Chloroform is a very suitable fluid, which dissolves the alkaloid at the ordinary temperature in all proportions and leaves it in a unaltered state on evaporation. Benzene dissolves it but sparingly in the cold (15°), but easily at 80°, about 1 in 10; this fluid is, therefore, well adapted for the purification of Echinopsine. The hydrated base is soluble in benzene with much more difficulty than the anhydrous compound; addition of water to the cold solution of the latter therefore causes a further separation of alkaloid.

The solutions of Echinopsine are all colourless and do not show fluorescence, neither when acidified with sulphuric acid.

Echinopsine is optically inactive (a 2,5 pCt. alcoholic solution examined in a 10 eM. tube showed no polarisation at 15°.)

An aqueous solution of echinopsine faintly acidified with hydro- chlorie acid is a bitter-tasting liquid; a hypodermatical injection of 10 milligrams in a mouse proved fatal. Prof. Dr. R. Kopert of Rostock has, at my request, closely studied the poisonous action (see Addendum I).

Echinopsine gives precipitates with phospho-molybdie acid, solution of iodine, Mayer’s reagent, picric acid, tannin, mercuric chloride, gold- and platinic chloride, potassium thiocyanate, potassium ferro- cyanide and potassium chromate. The delicacy of these general alkaloid-reagents is but moderately great; one drop of a solution of echinopsine 1/15), gives precipitates with a drop of all the said ‘reagents; solutions of '/j999) only with the first five, of '/joo009 only with the first two. Solutions of 1/95990—"/so000 are to me hardly bitter; this is also the limit of the picrie acid and mercuric- potassium iodide test. (Mayer’s reagent).

The latter reagents are well adapted for micro-chemical reactions but an aqueous or alcoholic solution of iodine is so in a still higher degree (limit 1: 100000); the crystalline precipitates obtained with mercuric chloride, potassium thiocyanate, potassium ferrocyanide and potassium chromate are also very useful.

The localisation of Echinopsine in the tissues may be very plainly

ely

traced by the aid of iodine solution which yields a beautiful crystalline precipitate in the cell. This study has been undertaken by Prof. Dr. Ep. VERSCHAFFELT at Amsterdam, who will communicate his preliminary results in Addendum IT.

Both the anhydrous and hydrated Echinopsine excel by erystall- ising unusually easily; from every solvent even traces of alkaloid leave a beautiful crystalline spot. The hydrated crystals belong to the rhombic system.

Echinopsine, although a weak base, is very stable.

Echinopsine does not decompose, when melted, until 350°, when it gradually chars, but even after having been heated for an hour at 450°, the liquified mass yield yet about one-third of unaltered alkaloid. Melted with potassium hydroxide it gradually forms a redlead-coloured resin, whilst ammonia is being evolved and an odour of pyridine is perceptable. Kchinopsine dissolves almost colourless in mineral acids, also in sulphuric acid on adding weak or strong oxidising agents. It also yields, under circumstances to be investigated later on, particularly by the action of acids by a high temperature, a decomposition product, which may be recrystallised from water and then appears as brown hard nitrogenous crystals which still give alkaloidal reactions, may be extracted from an acid fluid, by means of chloroform, and melt at 198°.

Echinopsine has a special reaction which should not be overlooked. Moistened with a dilute solution of ferric chloride it gives a fine blood-red colour; other colour reactions have not yet been observed.

This base forms a number of salts eminently crystalline but of a loose combination; the amount of water of crystallisation is not constant.

The first combustions of the Echinops-alkaloid did not give con- curring figures for carbon. The melting point was not only raised, (at first it was 140°), when the total alkaloid, however colourless, was still further purified, but the percentage of carbon (at first 73 pCt.) 1) increased owing to the previous admixture of accom- panying alkaloid closely related to Echinopsine. But even the analysis of chemically pure Echinopsine presents difficulties; this substance is extraordinarily troublesome to ignite and gives easily a too low carbon figure unless it is ignited in a current of oxygen. I will

) Analyses of the total alkaloid : 0,1760 gr. gave 0,4734 gr. of CO, and 0,0950 gr. of H,O, therefore C. 75,4 pCt. and H 6,0 pt. 0,1366 a , 0,3650 v ” 4 0,0818 ” a wv r 72,9 a ” ” 6,6 a

0,1522 #« y» 12,3 c.c. of N. at 18° and 765 mm. therefore N. 9,5 pCt. 9 Proceedings Royal Acad. Amsterdam, Vol, III.

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only mention here those elementary analyses, which have been used as the base of the formula. A part of the analyses was done by Mr. J. Sack, assistant in this laboratory.

Estimation of carbon and hydrogen.

J. 0,1758 gr. of Echinopsine gave 0,0950 gr. of HO and... .. gr. CO,. Il. 0,1522 w« , uv 0,0844 woe vw 0,4290 4 w TI. 0,2208 , ” v 0,1194 u ” ” 0,6186 ” yw IV. 0,1196 ~» w v 0,0606 e » « 0,3868 7 ~% therefore : I. ke IIL. Ie H. 6,0 pCt. 6,2 pCt. 6,0 pCt. 5,6 pCt. C. 76,9 » 76,4 76,8 ou

Estimation of nitrogen.

0,2100 gr. of echinopsine analysed by the Kjeldahl-method con- sumed 11,6 cc. of N./;, sulphuric acid, corresponding with 7,7 pCt.

of nitrogen. 0,2410 gr. consumed 12,8 ce. N./;, acid, corresponding with 7,4 pCt. of nitrogen.

Determination of the molecular weight.

Mol. Weight. 0,0820 gr. of echinopsine in 17,5 gr. of benzene gives an increase of 0,07° 157 0.5063 4 » ” » 11,9 » » alcohol 7 ¢ ” v 0,28° 175 0.5740 » » Y » 17,5 « , benzene » wW y n 0,46° 185 0,8310 » » u v 17,5 4 « » you ” w 0,70° 177 0,9890 »# » a » 17,5 0 « ’ sou u y 0,79° 186 0,1990 “ou 7 ” 17,5 you 7 ” 7] 7 “ 0,16° 185 0.5020 wv wu y u Vio oy 2 5 uw ” wv 0,43° 174

The elementary composition may be expressed by the formula C,, Hy NO. The analytical figures also agree well with (Cj; Hi9 NO), but this formula must be rejected on account of the results of the determination of the molecular weight.

Found. Calculated for C,, H, NO. iT: I. nS elves Vie Vile He 60; 69/060" 95.6 5,3 Cc — 769 764 768 —- — 77,2

N. (40 ET 8,2 Op = _ SS

The calculated molecular weight of this formula is 171; the average of the found molecular weight is 177.

Estimation of water in hydrated echinopsine.

Found. Calculated for C,, H, NO, aq. 10,3 pCt. 10,0 pCt. 10,0 pOt. 9,8 pCt. 9,5 pCt.

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Analysis of some salts of echinopsine.

Echinopsine hydrochloride. Is a gritty crystalline powder, easily soluble in warm water, and even in the cold more freely soluble than the free base. If a crystal of hydrated Echinopsine is added to a drop of dilute hydrochloric acid, it changes into a white crystalline powder, which disappears on warming. On slow evaporation the salt is deposited in fine, large rhombohedra, on rapid evaporation in microscopic six-sided plates. The hydrochloride is well adapted for physiological experiments; at first it tastes acid, afterwards per- sistently bitter. It loses hydrochloric acid already at 105°. The air-dried salt, pressed between blotting-paper, retains from 6,9—14,4 pCt. of water (2 mols. of water = 14,8 pCt.), which it soon loses when placed in a dessiccator over sulphuric acid.

Amount of hydrochloric acid (of the anhydrous salt). 1) 0,2080 gr. takes 0,972 cc. N./potash or 0,0352 gr. or 16.9 pet. of H Cl.

)) CRISKYA G5) aye = DMR ADE, 35 LORS aes sh O;Onest a te tgs 3) 0,2147 ” oy 1,025 2 »”» ” 0,0374 » ”» 17.4 ” 3 ” Found. q Calculated for C,, H, NO, HCl 16,9 pet. 16,9 pct. 17,4 pet. 17,7 pet.

Echinopsine sulphate. Crystallises very beautifully in elongated colour- less needles, which dissolve slowly in cold but easily in warm water.

The sulphates prepared by me contained respectively 26,0 pet. (8 mols. = 24,6 pet) and 8,2 pet. (2 mols. = 7,6 pet.) of water. Amount of sulphuric acid (calculated on the anhydrous sulphate). 1) 0,1777 gr. of anhydr. sulph. takes 0,840 cc. of N. potash or 0,0412 gr. or 23,2 pet. of H, SO, B30 2, culph Sng. ., 0,490, , » > 0,090,999. 5

Found Caleulated for (C,, H, NO),, H, SO, 23,2 pet. 22,9 pet. 22,3 pet.

Echinopsine nitrate. Is also crystalline and not easily soluble in

cold, easily soluble in warm water.

Amount of nitric acid (of the anhydrous salt). 1) 0,1462 gr. takes 0,640 cc. N.potash or 0,0403 gr. or 27,5 pCt. of HNO, 2) 0,0521 » » 0,230 » z S OLOTSa a pe e78i zs, > Found Calculated for C,, H, NO, HNO, 27,5 pCt. 27,8 pCt. 26,9 pCt. Echinopsine oxalate. A beautifully crystallised salt which, when air-dried, contained 18,1 pCt. of water (4 mols. = 14,3 pCt.).

Amount of oxalic acid (in the anhydrous salt). 0,1777 gr. takes 0,830 ce. N.potash or 0,0373 gr. or 20,9 pCt. of C,; O,H, Found Calculated for (C,, H, NO),, C, O, H, 20,9 pCt. 20,8 pCt. Kchinopsine picrate. A yellow crystalline salt very slightly solu- ble in water, of varying composition and melting at about 215°, decom- posing hereby. The picric acid, present in the alkaloidal salt and O*

=

( 20 )

obtained by shaking with petroleumether after decomposition with sulphuric acid, amounted to 81,1 pCt.

On combustion 0,1040 gr. of the same picrate gave 0,0380 gr. of H,O and 0,1598 gr. of COs.

Found Calculated C. 41,9 pCt. 40,0 pCt. Her A0r 3,6 »

Echinopsine mercuric chloride. Is beautifuily crystalline and melts exactly at 204°. It dissolves easily in boiling water, but requires 120 parts of water at 15°.

Kchinopsine mercuric iodide. The precipitate caused in a solution of echinopsine containing a slight excess of hydrochloric acid by Mayer’s reagent is a yellowish-white, sticky, substance, which becomes coarsely crystalline when recrystallised from alcohol of 50 pCt. and melts at 178°. 0,150 gram of echinopsine yielded 0,455 gram of this bi-iodide, dried at 100°.

Found Calculated for (C,, H, NO, HJ), + Hg Jy.

33,0 pCt. of alkaloid. 32,6 pCt.

Echinopsine acetate. Is also crystalline and readily soluble, even in cold water, to a bitter fluid; the salt is very unstable and loses its acetic acid completely at 100°.

Todo-echinopsine. The crystalline precipitate produced by a solution of iodine in a liquid containing echinopsine differs in colour and composition according to the concentration and excess of the iodine employed; it also readily loses some of the iodine. It is somewhat soluble in boiling water and separates on cooling with a light-choco- late colour. When carefully dried, washed with carbon disulphide and recrystallised from alcohol, it forms a coffee-coloured crystalline powder, which melts at about 135°, but gets already sticky before that temperature is reached.

As regards the nature of Echinopsine, the following should be observed. It cannot escape notice that this substance behaves chemic- ally more like an amide than an amine, namely like a cyclical amide, while the physiological action is strychnine-like similar to piperidone, pyrrolidone ete. To this may be added that the colour- ation with ferric chloride and the empirical composition also seem to point to a substance as phenylpyridone. I made some reduction and oxidation experiments‘) to learn the structure of Echinopsine,

) Reduction of echinopsine. Ueated in a combustion tube with zine dust in a slow current of hydrogen, echinopsine yields a distillate consisting of a yellowish- brown oily liquid having the odour of pyridine; it is heavier than water and insoluble therein but is readily dissolved on adding hydrochloric acid. This solution was

( 21 )

but the greater portion of my material had already been exhausted by the general study of this new substance. I can only say, that Echinopsine, although not identical with the phenylpyridone described in the Berl. Ber. XXIX, 1697 is probably related to the same.

The analysis of Hcehinops is not completed with the investigation of crystalline Echinopsine.

There are, namely, indications that other special substances occur in this material. In the first place it must be observed that the erystalline Echinopsine possesses only a part of the bitterness of the raw material; a decoction of the fruits is still bitter in the pro- portion of 1: 3000—4000, Echinopsine hardly any more at 1 : 30.000 ; there must, therefore, exist some other active components which cause or increase this bitterness.

The precipitate from Mayer’s reagent in the acidulated aqueous solution of alcoholic extract of echinops is much more considerable than can be accounted for by the quantity of echinopsine which might be prepared from it, and it even amounts to 0,2 gram for 1 gram of seed, being of a different nature than the precipitate obtained by Mayers reagent in an acidulated watery solution of pure Echinopsine; it has for instance a much higher melting-point.

I have devoted no small amount of labour to the study of these -other constituents, but for the present I can only offer the Echin- opsine in a pure condition and venture some information about the accompanying alkaloids, without wishing to pretend that the following alone account for the missing echinops-alkaloid-complex.

It has already been mentioned that the purified total-alkaloid, when repeatedly recrystallised from benzene, gradually acquires a higher melting-point. There is present a crystalline accompanying alkaloid

repeatedly washed with ether, the base was liberated with aqueous caustic potash, distilled in a current of steam and removed from the milky distillate by means of ether. It was thus obtained as a colourless liquid of the same main properties as the crude distillate, namely heavier than water and insoluble in the same. With hydrochloric acid it forms a compound soluble in water of a burning taste giving crystalline precip- itates with picric acid (yellowish-white), platinum and gold chlorides (first yellow, afterwards pale-red) which all melt and decompose at 200°; also a compound with mercuric chloride consisting of velvet-like white needles melting at 159°. These data do not admit of any identification with one of the known phenylpyridines,

Oxidation of echinopsine. Echinopsine was oxidised in the cold with 6 times its weight of a neutral 4 pCt. solution of potassium permanganate, the filtrate was treated with carbon dioxide, evaporated to dryness and the residue extracted with alcohol containing hydrochloric acid; this left undissolved a nitrogenous, hygroscopic substance soluble in water but insoluble'in ether. It begins to melt at about 120° and yields on stronger heating an oily distillate having the odour of pyridine and diphenylamine,

(3-Echinopsine), which behaves in most respects like Echinopsine, but passes readily from the acid solution into chloroform, gives no colour reaction with ferrie chloride, contains less carbon than Echinopsine, is a still more weak base and melts at 135°.

Mention has also already been made of the substance soluble in water, alcohol, amyl alcohol and benzene, which causes the green fluorescence of the solutions of the crude alkaloid, Eehinops-fluores- cine. The benzene motherliquor obtained in the preparation of Echinopsine, leaves on evaporation a dark brown mass; this was dissolved in dilute acetic acid, washed with petroleumether and ethylether and then again shaken out with chloroform ; the fluorescine passes from the acid, but more readily from the alkaline solution, | into that solvent. It was dissolved in acidulated water and precipi- tated with picric acid. The picrate, after being washed with water and dried between blotting paper, formed a sulphur-yellow crystalline cake melting at 210°. This picrate was decomposed with an aque- ous caustie potash of 10 pCt. and the base thus liberated was taken up with chloroform ; it seemed to be admixed with much Echinopsine. After this had crystallised out, the fluorescine remained as a brown resinous substance of alkaloidal nature, melting at 105°, not bitter, and with an extraordinarily large fluorescing power. The green fluorescence of the light brown solution is not changed by alka- hes; addition of acids renders it colourless but on exposure to the air it soon regains its colour and fluorescence. The yield of fluorescine is small, the fruits of E. exaltatus containing a larger quantity of it than any other species, examined yet. To judge from the picrate precipitate, the purified material of H. Ritro contains about 0,10 pCt.

There is also in the motherliquor a non-fluorescent amorphous alka- loidal constituent, Hehinopseine, present. It is a brown mass decom- posing on the waterbath and turning cherry-red thereby ; this change of colour is also caused by alkalis. From an acid, but more readily from an alkaline solution, it passes into chloroform. The solution in very dilute sulphuric acid is bitter-adstringent, has a flavour of benzylaldehyde and gives with picric acid an abundant yellowish- green precipitate, also melting above 200°, decomposing thereby. This picrate was also decomposed’ by aqueous caustic potash and the base dissolved in chloroform; the chloroform residu, which was cherry-red, still contained much Echinopsine; the Echinopseine being obtainable only as a resinous mass, melting at 125°; I therefore, had to give up further research in this direction.

Both Echinopseine and Echinops-fluorescine obstinately adhere to

( 23 )

Echinopsine, causing this to exhibit for a long time a green fluores- cence and to turn occasionally pink, when moistened with distilled water. This colourreaction is caused by a trace of alkali, presents in the distilled water, from the glass vessel.

Finally a few words on Echinops oil, which is met with when extracting the alkaloid. When quantitatively estimating the oil by extraction with ether, 27,5 pCt. was found in the seed of HL. Ritro, It is a pale yellow sweet thick oil, of 0,930 sp. gr. at 15°, slowly drying. It has the striking property to dissolve on warming in an equal volume of absolute alcohol; on cooling an emulsion is formed and then the oil separates almost completely; at 15° the oil requires about 25 parts of alcohol for solution. Methylalcohol does not possess this remarkable property '). The oil is soluble in all proportions in kerosene, ether, carbon disulphide and benzene, also in an equal volume of warm glacial acetic acid. The saponification number of the oil is 194°, the melting point of the solid fatty acids 41° and the solidifying point 39°.

M. GRESHOFF Laboratory, Colonial Museum, Haarlem.

eho DU Nee On the physiological action of echinopsine. By Professor Dr. R. Kopert.

In October 1899, I received from Dr. M. Gresnorr of Haarlem half a gram of crystallised Echinopsine hydrochloride.

With this small quantity only 3 experiments could be made with frogs and 2 with guinea-pigs.

These, however, sufficed to establish the following facts:

1. Echinopsine hydrochloride is a poison for cold-blooded and warm-blooded animals (frogs and guinea-pigs).

2. With both classes of animals the actions are similar and consist of an irritation of the motor-centres of the nervous system.

3. Both brain and spinal chord are taking part in this irrita- tion. The irritation of the brain is only noticed in the case of warm-blooded animals and then shows itself as trismus and most violent spasmodic contraction of the masseteres. The irritation of

‘) Other fatty oils from the seeds of the Compositae are also more soluble in boiling alcohol than is usually the case, but not to such an extent as Echinops oil. -Madia oil for instance, requires 6 parts of boiling and 30 parts of cold alcohol.

( 24 )

the spinal chord which, in the case of the frog, is not stopped by severing the brain, is apparent from the convulsion of all the four extremities. In the case of warm-blooded animals these may appear as klonus and tonus occasionally even as opisthotonus.

4. When a very large dose is administred to a frog, the irrita- tion instantly passes into paralysis, whilst with a smaller dose the irritation symptoms may continue for 4—5 hours.

5. When a dose is administred to cold-blooded animals in suffi- cient quantity to cause irritation, it will be noticed that before the first convulsions set in and during the intervals, there exists a state of torpor, dotage and reflex-debility.

6. In the experiments on frogs the heart is decidedly weakened

and such by doses which do not yet paralyse the spinal chord. 7. The complete action of echinopsine reminds of that of a mix- ture of strychnine and brucine but is not identical with the same, as the ophisthotonus and the reflex-irritation are not so marked as with minimal doses of strychnine and also because the heart is more affected than is the case with strychnine.

8. Doses: A subcutane dose of 0,02 gr. does not affect esculentae of ordinary size (winter frogs); 0,05 gr. causes an irrition lasting, with intervals, for several hours; 0,08 gr. paralyses the nervous system without previous irritation and also paralyses the heart at the same time.

A dose of 0,10 gr. has no visible effect on a guinea-pig weighing 325 gr., but 0,25 gr. kills the animal after suffering violent spasms for several hours.

9. Antidotes for echinopsine are to be looked for among those narcotics which do not weaken the heart.

10. It is not probable that anatomical changes oceur in echinop- sine poisoning cases, but I will pay attention to this matter when making experiments with the fresh material recently received from Haarlem.

Institute for pharmacology and physiological chemistry, University, Rostock.

AD DE N Dsus ie On the localisation of echinopsine. By Professor Dr. E. VERSCIAFFELT.

The research on the microchemical localisation of echinopsine in the tissues will form the subject of an elaborate paper in which

( 25 )

it will also be attempted to trace the relation between this localisation and the physiological signification of the alkaloid. Provisionally, attention will only be called to a few particulars respecting the distribution of echinopsine in the fruit of Echinops Ritro. For this purpose the method originally proposed by ERRERA was employed }), which is based on the precipitation of the alkaloid in the cells by means of iodine dissolved in potassium iodide or alcohol. With some plants mistakes may be made when using this method on account of the presence of other substances which also give preci- pitates with iodine such as amines, glucosides, albuminoids ; but when dealing with Hchinops no fear need be entertained as the iodo-echi- nopsine precipitate is not like the others *) in the form of a minute granular brownish-red precipitate but in large exceedingly character- istie crystals. The crystals formed in the tissues will be found under the microscope to be similar in appearance to the iodo-com- pound of pure echinopsine. As solutions of iodine were so eminently satisfactory it was not thought necessary to use other reagents on an extensive scale. The manner these behave towards the alkaloid in the tissues will be mentioned later on.

The scales of the involucrum which surround the ripe fruit in a dry condition, are free from alkaloid just like the dry fruit walls and their toothed hairs. The cells of the embryo, on the contrary, are mostly rich in alkaloid. This fleshy straight embryo practically occupies the space of the coalesced fruit-wall and seed- coat as far as the latter is developed. The embryo is surrounded with a double layer of thick-walled cells which like the cells of the embryo itself are filled with reserve material.

The morphological nature of this membrane which easily detaches either way from the embryo, as well as from the fruit-wall, cannot be explained witb certainty without watching the course of development. It may be a rudimentary endosperm, also a seed integument. The cells. of the embryo contain fatty oil and albuminoids as reserve materials. The fatty oil may be rendered visible in the ordinary way by killing the cells, for instance, by heating or by means of an acid which causes the oil to be liberated and collect in large drops. The cells are closely filled with aleuron-granules, which are present in such large numbers that they are only separated from each other by a network

1) Errera, MaisTr1au et Craustriau. Ann. Soc. Belge de Microsc. 12, 1889, ERRERA thid. 13, Mémoires.

2) Compare the researches of pE Whyre, DE WitpEMaN, Anema, Motte, Lorsy, Bart and others.

( 26°)

of thin plates consisting of amorphous oil-containing protoplasm and often flatten one another (see Fig.). These aleuron-granules are small, their diameter being at the most ore third of the size of those of Ricinus and Linum, but they are fairly equal in size. Their further structure may be silently passed over.

The cells of the already mentioned double layer present around the embryo also contain granules of an albuminous nature but these are much smaller than the aleuron-granules of the embryo.

Annexed figure gives a representation of a group of cells from the cotyledons of Echinops Ritro after treating a section with glycerol mixed with tincture of iodine until the mixture assumed a mahogany-brown colour. I have made frequent use of this mixture as well as of iodine dissolved in potassium iodide. After the sections had stayed for a while in the mixture, they were preserved and mounted in pure glycerol.

The figure does not, however, show what is seen the moment the objects are treated with the reagent, then large crystals are not for- med at once. In the beginning a minute brown-

Eh ish-red granular precipitate is obtained which, a. borders of the aleuron- however, unites after a few minutes to the granules. larger aggregations of dark coloured needles,

4. most nu us needle- yiate : oe Most numerous nee as shown. It is interesting to watch under the shaped aggregations of the :

iodo-echinopsine compound, Microscope the first formation of the precipitate ; ce. less numerous brown it then appears to form in the aleuron-granules Bite which instantly turn brownish-red and show afterwards inside their mass darker and larger crystals. The amorphous protoplasm between the aleuron-granules turns at once pale yellow and remains so. Echinopsine occurs, therefore, only in the aleuron-granules and was in consequence formed within the vacuolae of the unripe seed, which is as might be expected.

The crystals which are visible in the cells after some time belong to two very plainly different forms. The more numerous are dark coloured manifuldly-grouped needles 6. These agree, as regards appea- rance, very well with the precipitate caused in a solution of pure echinopsine of which Dr. GresHorr was kind enough to present me with a certain quantity. Between these needles are noticed a smaller number of light brown, more plate-like crystals of a peculiar feathery appearance c, which I have not been able to observe in the iedine-

( 27)

precipitate of the pure alkaloid, at least under the conditions in which I worked, so that I feel inclined to suspect the presence of the iodo-compound of an accompanying alkaloid. The double peripheric layer of the seed contains alkaloid. In the cotyledons, a beginning of differentiation is observable in palisade and spongy parenchyma, a phenomenon occurring in different plants the cotyledons of which afterwards turn green and assimilate (for instance, Brassica, Linum). There is, apparently, no difference in the amount of alkaloid contained in the tissues. The epidermis of the cotyledons also contains much alkaloid. The procambium bundles which traverse the seed lobes are, on the other hand, perfectly free from alkaloid and the same is true of those of the root. The bark of the latter is quite as rich in echinopsine as the tissue of the cotyledons.

The centre of the root which is surrounded by the procambium bundles is poor in alkaloid, so that here, a cylinder poor in alkaloid is separated from the bark rich in alkaloid by a layer free from alkaloid.

This want of alkaloid in the procambium of the embryo is interesting because, as will be more fully demonstrated later on, tolerably much alkaloid is actually found in the bast (phloem) in the further course of the development.

Botanical Laboratory, University, Amsterdam.

Physics. — ‘On the relation between Radiation and Molecular Attraction”. By J. D. vAN DER WaAats Jr. (Communicated by Prof. J. D. van DER WAALS).

At the end of a paper in the Proceedings of the Royal Acad. of Sciences of March 1900 I expressed my intention of investigating whether the ponderomotoric action of radiation could give an expla- nation of molecular attraction. The course which I would take, was the solution of the equations of motion of a number of vibrators which act on each other and are subjected to no other forces. If we could solve these equations, and if this action proved sufficient to explain the molecular attraction, we might be able to deduce from this whether ithe quantity a of the equation of state is a function of the temperature, and if so, what function, and whether the attraction is really proportional! to the square of the density, or if it is so only by approximation.

I have however, not succeeded in finding the function solution of this. problem, not even for the case that there are only two

( 28 )

vibrators. Nor is the general solution, to be used. The action of the molecular force is only felt if the distance of the

r molecules is very small. Then ae ee t'—t is very small and we

should have to take into account a great many terms.

The following considerations may however serve for a preliminary investigation as to whether the order of the quantity of the forces of radiation is the same as that of the molecular forces, or whether they are so small that we are forced to assume that there acts besides the forces of radiation, another kind of foree between the molecules.

For this purpose we examine how much smaller the quantity of energy is, which a set of vibrators has, when they are influenced by one another, than the sum of the energy which every vibrator would have separately, if it were alone in space with its own am- plitude. The difference of these two quantities of energy may be considered as the energy which the vibrators would lose if they were brought from an infinite distance to the places they now occupy, provided care be taken, that they had the same amplitude during the whole process (i. e. that the process was carried out isothermically).

An exact solution of this problem would be very intricate and the energy of the field would certainly have to be taken into con- sideration. I shall, however, assume that the energy to be found is by approximation represented by:

$24nV*(far+ga,+ha,).

This comes to the same thing as if we put the moment of a vibrator o at a given moment and then seek the difference of the following two quantities of energy:

1st The energy necessary for giving the moment a to the molecule when it is not subjected to any action of other molecules.

2nd The energy necessary for giving the moment to the molecule, When it is in a region, where the electrical displacement has the components /, g, h.

If we take the sum of these quantities of energy for all molecules, we have taken both the energy which molecule I has with respect to molecule II and that which molecule II has with respect to molecule I. We have therefore to divide the result by 2.

If the quantities a, and f were independent of each other, faz added for all the molecules, would yield o. In consequence, however, of the partial regulation of the vibrations of the molecules with respect to the electric forces, f and az will not be independent,

( 29)

(Compare “Entropy of Radiation II,” Proc. Roy, Acad., Febr. 1900). The same holds of course also good for ga, and haz.

I shall assume that every molecule on an average has absorbed the amplitude ob} from the field. If we knew o as function of the temperature and of the density for every substance we had a com- plete solution of the problem. We do not know o however, and can only compute how great o must be in order that the forces of radiation account for molecular attraction. We must find a fraction and we may expect that the fraction will not be very small.

For f I shall take the value as it is calculated in “Entropy of Radiation J,’’ (Proc. Roy. Acad., Dec. 1899). In doing so we are guilty of the inconsistency of taking a value for /, calculated on the supposition, that the motion is perfectly irregular, while the energy which we are seeking, is the very consequence of the partial regulation. We cannot, however, calculate another value for /, if the way of regulation is not known and the mistake which we make in doing so, is probably slight.

The mean value of ga, and ha. being equal to that of faz, we may write for the energy:

3 B=] 24aV* fas

and we need only take those terms of az which are caused by the forces of the field; so:

2nt 20t B=62 V2 = (feos = + fo sin 7 ) x

2Qat 2at & cos if + bre sin a)

E where bi =p fit dhs bz = —QGfitPhe 4 7? f V22 S15) rene ; Ee an GA 58 f \2 2\2 e& 1 /2n6 Ge ela = aes) 2 e 1 /2n\3 V2e 3B m V =) g=—4a se :

m 7472 f \2 2\2e% 1 /2 26 ( is +)+(~) (=) T? m 3/7 mV2\ T

') See note at the end of this paper,

( 30 )

’ 2 at PRT AG wt On an average the terms containing sin Sar will become

zero and also {hose containing the product f,f. As the mean of

2 nt 2nt . 2 both sin? = and cos? 7 8 4, and the mean of ie equal to that

of ap we find: E=61V*op =f?

For S fi we may write }7«°, in which » represents the number of molecules per unity of volume and « the quantity, defined at pag. 322 (Proc. Roy. Acad., Dec. 1899). For ¢ we may, however, not take the approximated value calculated there, which holds only for points at some distance from the source.

Let us represent a volume-element by r? dr sin@d0 dp and let us call the shortest distance, to which two molecules can approach ¢, then:

sae 1 e 2a e& —2n a aout J f 7? dr sin 0 dO dep e—2¥r p 0 0

Wolietee: te Ses 1\2. /3a2 1 \24n? (Ce gue ya

rt ried

a} x 2a —— 1 &=—2n a wal SS r° dr sin 0 dO dp . e—2r p 0-10

A 1? Ir hie 0 eet well as 2 1 1 3 (== 2 sin + aay oy (5 cos a— ) -|- ai (8 cos 0 -+- 1)| . If we take into consideration that:

7

2 4 e 2 if sin® Od0 = — and il sin O cos? 0 db = — 3 3

0

0

this becomes:

Roars Te 1 af. [(? PN? A~ © Alpe Ved =i =a)¥45 sncehen —2ur 87 Bi .) "3 tga eee ‘al Be:

(31 )

The first term may be at once integrated and furnishes :

1 ( 47? i 4 aE | | eee — ¢—2EP , 2u A? 3

The two other terms cannot be integrated; if however we omit

the factor e—2“", the last term becomes predominant, viz 12

v The terms with small r appear to have most influence, even if e-2er ig omitted. This is a fortiori true if the factor e~?” is pre- served. For terms with very small r the factor e—2" is nearly 1,

1 : - so that 12 =a) is really an approximated value of the integral of g

Lee ; ] 4 1?\2 the third term. Further —— is great compared with —— es , 80 v3 2a\-

that we may write by approximation : = i

SS a0

a ri g3

In order to determine the quantity «? we take into consideration

that for one vibration the quantity of energy, emitted per second is 1 2 8 y2 n* Py aa roe 1 equal to Ts apes AS

I represents the mean quantity of energy emitted by a molecule. KE. Wiedemann!) calculates that 1 molecule platinum at a temp. of 1000° emits 3,3.10-16 Gr. cal. = 1,4.10—® erg. per second.

_ If we accept the law of STEPHAN, we find for Z at about 0” the value:

1,4 2a 10=* ers. ==32)2 10-1,

For the quantity of energy sought we find therefore:

") Wied. Ann. XXXVIL, 2, Bl. 203.

( 32)

We shall use the following approximated values as given:

n= 5.101 Ree OTS) m

V= 3.101 < = 2,5.10-5 }) m

Sass!

Taking these values into account we can give p a simpler form. To that purpose we determine & from the equation:

2k pee eo +=o(a a= )

We bave to use the positive root of this equation, which has a value of about 107, Now we see that 2 is small compared with 472

ae and may be neglected, so that we may write approximatively

h 2 9 te et pee, m V The term with %*° may be neglected, and we find:

ut ee ee T2 m - 4 \mV T2

This quantity is of the order 10!*, The square of it occurs in the denominator of p and is of the order 1075. This term may therefore be neglected, as the other term of the denominator

E € zy ik is of the order 10%. So we find for p: m 3 ( e y' (ai V2e 4 \mV aE 7

m eye aN ee 3 G mV T?

1) Lorentz, Versl. Kon. Akad. vy. Wetensch., Maart 1898. *) Proc. Royal Acad. of Se. Amsterdam, Febr. 1909, p. 417.

(33)

or 27 1 e

~ 16 2m

P Ree

If we substitute this value for p in 2, we find:

So we see that / depends in a high degree on 4, and that the value which we find, is quite determined by the value for 4 which we assume. Now the quantity Z is determined for a continuous spec- trum, and it is not at once to be seen what value for 4 we have to take. I shall therefore have to confine myself to calculate, what value 4 must have, to make / equal to the energy of the molecular attraction. o is however also unknown and in order to calculate A, we have to assume a value for o. If we put o=1, we know that we take a too great value for o. The value of 4, which we calculate from it, is therefore the minimum-value which 4 must have in order to make / equal to the energy of the molecular attraction.

The energy of the molecular force, is, as we know, represented by = . For 1 c.c.M. air under normal circumstances this is 2700 erg. For Z we have however taken the quantity of energy emitted by one molecule platinum. Therefore we have to take also the quantity

a e . . — for platinum. As substances with great molecular weight have v

also a great value for a, we shall take a for platinum ten times as great as it is for air, and put therefore:

That platinum under these cireumstances forms a phasis of little stability or perhaps even an instable phasis, is of no consequence.

. 7 . . a . “ * If we replace £ by this value of — and further all quantities

v by their numerical values, we get: 243. 1 6 2,5. 10-18 Te as toe et 2,2.10-1 512 7 3.10!° 27.10—24 or 9.512

an 10 137,5.10.2

Proceedings Royal Acad. Amsterdam, Vol, III.

( 34 ) So we find by approximation:

fi BEI WO

At 0° the wave-length of radiation emitted in a sensible quantity is certainly greater than 10~*, while the greatest wave-lengths measured amount to + 22.10—*. It is therefore no unsatisfactory result that we have to take for 4 as minimum 3,16 . 10+.

Though the numerical result may not have much value on account of the great uncertainty of the numbers used, yet it pleads rather in favour of the supposition that the cause of the molecular attraction must be looked for in radiation, than against it. The-more so, as this supposition is supported by its simplicity. It is true that an accurate calculation of the molecular attraction from the forces of radiation would be pretty intricate, but we cannot doubt of the existence of the forces of radiation and the question is only: “are they the only forces, or does there exist another kind of force acting between the molecules and giving an explanation of the molecular attraction?’ And certainly the assumption of the first alternative is simpler than that of the second. In the meantime it will have to appear from later investigations whether this suppo- sition will be able to explain the action of the molecular forces more in particulars.

Nolte. The values for p and g used here are not quite the same as those which I found for them on pag. 417 Proc. Roy. Acad., Febr. 1900.

Two mistakes occur namely in the values given there. First the two quantities must have the opposite sign. Secondly Prof. Lorentz has pointed out to me that the formula, from which I start, and which is borrowed from formula 111 of his treatise in the Arch. Néerl. XXV, 5, is not quite correct. The two terms of 111 have both to be multiplied with ?/,.

To demonstrate this, we continue the series of calculations on pag. 486, which is there without good reason stopped at x, for two terms more, and replace the quantity occurring there :

u J «ie by : is rl. pane x — V x aE; y2 x —6V3 x

For x, we get then the following terms in addition to those which Loreniz took

into aecount: 1 : a) 24, 1 Fe eee 8a V# X J Gordr + 24n Vi xa lomcidce

: dx d*®x é r If we neglect the terms with er and WE? as they are of the order ( _

a “ is 2 , : : xy ; with respect to x and x and if we notice that integrals like | fo ——@r’ are zero,

a

because of the symmetry, these terms of x, contribute only the following terms for /:

1 S 02 ” : t 1 soe 02 af F ; ; a Bey ee eS oe = ee cet Sa V2. ay Baa VS Fey SF

Now: and

The two new parts of f are together:

il ze ( 1 (#—2')?) NY, e = — — —_ — =~ x. ek ee Oe re poe 12” V3

We have to multiply this with 42% V2p,dzr, in order to get the corresponding parts of the force acting on the ion in the direction of the z-axis, and then to integrate over the whole ion. This gives:

sft ( LL @=2'?} er Tx |) Qpdt ¥ Oo ete a | dt — PBT

The value of the second term remains the same when we substitute (y—y')® or (z—2'f for (r—2')*, and is therefore one third of what we should get, if we substituted ry? for (e—a')*. The foree which is to be added, becomes then:

te 22 0 Geos 4 aed -~ @& 3 «fe arf Sar ana yer ae ves Ree POR y

and if this is added to the terms of 111, only */, of this last value remains.

Chemistry. — ,Plumieride and its identity with Agoniadine”’. by Prof. A. P. N. FrRancuimont.

The name Plumieride has been given in 1894 by Dr. Boorsma of Buitenzorg to a substance which he had isolated from the bark of Plumiera acutifolia. Dr. Boorsma states i.a, that Plumieride does not

3*

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melt, that it is not a glucoside, that its composition is C,H )O)s-4+-H,0 and he concludes that it is a substance quite different from the one prepared in 1870 by Dr. Tu. PecKoxt, of Rio de Janeiro, from the bark of Plumiera lancifolia and called by him <Agoniadine. This substance was analysed and investigated in Jena by Prof. A. GEUTHER who gave it the formula C,,H),0,; it melted at 155° and yielded on boiling with dilute sulphuric acid a sugar and a brown, amor- phous substance and consequently was a glucoside.

In his review of 1895, it is stated by E. Merckx that he had obtained from the root of Plumiera acutifolia, a substance different from that of Boorsma, melting at 157—158° with evolution of gas. He gives as its composition C;7H72 Oz; + 2 H,0 and for its mole- cular weight 1074—1080, although the given formula requires 1280.

On the occasion of his last visit to Holland, our fellow member Dr. TREUB requested me to re-investigate the plumieride which I agreed to do. .

Preliminary experiments made me see at once that plumieride is a polyhydrie alcohol, optically active and fairly strong laevogyrate in aqueous solutions; also that it decidedly deserves the name of glucoside and that the sugar obtained in its hydrolysis is birotatory and dextrogyrate and also gives a phenylosazone which is identical with that of glucose, as shown by its melting point and rotatory power. I also noticed that the substance of Merck behaves in every respect, except in its fusibility, like Boorsma’s plumieride and could show with great probability that the difference is caused by a variation in the amount of water.

When rendered anhydrous, properly purified and crystallised from dry ethylacetate, both appeared to be identical; they do not melt and have the same rotatory power and crystalline form. When recrystallised from water they were again identical, had the same melting point and contained the same amount of water.

Still a difference might have been caused by the fact that BoorsMA had repeatedly boiled his substance with amylaleohol and that it was possible that this is not an inert solvent. I had, therefore, the substance prepared from the bark which had been forwarded to me from Buitenzorg, avoiding the use of amylaleohol and also a high temperature; this preparation after being recrystailised from dry ethylacetate was also identical with the other.

That plumieride yields fairly much glucose on boiling with dilute hydrochloric acid was proved afterwards by isolating the glucose in a pure, crystallised anhydrous state and identifying it by its melting point and rotatory power. At the same time the absence of

C Je)

mannose and pentoses was shown. Then if plumieride is boiled with hydrochloric acid of 10—12 pCt. strength, only insignificant traces of furfuraldehyde are formed, while the glucose is decomposed into formic and laevulinic acids, which were both identified, in the com- pany of a humus-like substance which is mixed with the second product of the hydrolysis of plumieride, a brown amorphous substance the weight of which amounts in this case to more than half the weight of the plumieride. On boiling with hydrochloric acid of 5 pCt. strength, glucose may be obtained one-fourth part of the weigth of the used plumieride although Jaevulinie acid is also formed here, by destruction of a part of the glucose; the weight of the amorphous substance is then about one-half of that of the plumieride. On boiling with hydrochloric acid of half a pCt. strength, the hy- drolysis of plumieride also takes place, although much slower, and a part of the glucose may also be decomposed of which I have con- vineed myself by actual experiment. The brown substance now certainly weighs less than half the weight of the used plumieride, but still always contains a humus-like decompositionproduct of glucose. It is, therefore, plain that the exact quantity of glucose which plumieride is capable of yielding cannot, apparently, be deter- mined in this manner and that the second product from the plumie- ride is not to be got in a pure state in this way.

I hope to communicate later on, at the close of the investigation, about this brown substance and the hydrolysis of plumieride by enzymes.

After plumieride had been undoubtedly characterised as a glucoside, it was desirable to study agoniadine which is also known as such and also gives a brown amorphous substance on hydrolysis, and to explain the difference between both substances, should a difference exist. The difference in melting point goes for nothing.

As bark from Plumiera lancifolia was not obtainable, I have made use of about 5 grams of agoniadine sent by Dr. PEckoLr. This pre- paration, which was not pure, gave after being repeatedly crystallised from dry ethylacetate a beautifully crystallised substance perfectly resembling anhydrous plumieride in shape as well as in chemical and physical properties. It was not fusible without decomposition and had the same laevorotatory power etc. Our fellow member Prof. Beurens had the kindness to compare microscopically different preparations of plumieride with each other and with those obtained from PrcKoLtT’s agoniadine; on account of the fact that they have the same form, polarisation and index of refraction, he thinks he may safely conclude that they are identical. I, then, do not hesitate

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to declare that the substance, isolated from PEcKOLY’s agoniadine, is identical with plumieride.

Although it is customary in such cases to retain the name given by the first discoverer, it seems to me that the name ,plumieride” is preferable. It reminds of both plants from which it is obtained and by its termination it is more suited for a glucoside. 1, therefore, obliterate the name ,agoniadine”’, which on account of its termina- tion reminds more of an alkaloid, from the chemical literature and in future will call plumieride the substance discovered by PECKOLT in 1870 in the bark of Plumiera lancifolia, which substance has afterwards been found by Boorsma and also by Merck in the bark of Plumiera acutifolia.

Plumieride is a methyl-ester (a methoxyl containing substance) then it yields methyliodide with hydroiodic acid of a certain con- centration. It yields, by the action of dilute alkalis or barytawater at the ordinary temperature, or by water alone at a higher temper- ature, an acid which I have provisionally called plumieridic acid '). This does not contain methoxyl but is a glucoside which on boiling with dilute acids yields a brown amorphous substance and a sugar, the osazone of which has the same melting point as that of glucose.

If plumieride is now simply a methyl-ester of plumieridic acid as nearly everything found as yet seems to bear out, the easy decom- position (saponification) by alkalis and even by water and the con- sequent difficulty to obtain a pure preparation by recrystallisation from water becomes apparent.

I, finally, wish to add that the solution of Peckort’s preparation in cold water was of a very brown colour and strongly reduced . FeaLtna’s solution; when first extracted with ethylacetate it left a good deal of a brown amorphous substance behind and it was only by repeated crystallisation from ethylacetate, which operation was attended with great loss, that it was obtained pure. The impure fractions contained glucose.

Chemistry. — ‘On the crystallised constituent of the essential oil of Kaempferia Galanga L.” By Dr. P. van Rompuren.

When the rhizomes of Kaempferia Galanga L., a plant belonging to the family of the Zingiberaceae, which is cultivated on a small seale by the natives in Java for medicinal and culinary use and

') The name plumierie acid has already been given by our deceased fellow member

Prof, A, ©. Oupemans Jr. to another acid obtained from the milky juice of Plumiera acutifolia.

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known under the name of “kentjoer” or ‘tjekoer”, are distilled with water, the first fractions contain a small quantity of an essential oil lighter than water. Afterwards an oil heavier than water distils which deposits abundant crystals, whilst towards the end a erystal- line substance is almost exclusively obtained. The distillation must be continued for a long time as this substance is but little volatile. The yield and also the relation between the solid and liquid product differ very much with different samples; most likely this depends on the age of the rhizomes, which matter [ am now making the subject of practical investigation.

The crystals deposited from the oil may assume very large di- mensions; they are very shining and transparent, melt at 50° and may be obtained in a beautiful form by reerystallisation from alcohol. A 20 percent alcoholic solution appeared to be optically inactive.

The elementary analysis gave numbers, which lead to the formula Cj, Hy, 03, while the molecular weight, determined in acetone by LANDSBERGER’s method, came to 197, 206 being calculated.

On heating with alcoholic potash this substance yielded almost at once a mass of beautiful little crystals of a potassium salt, from which sulphuric acid liberates an acid crystallismg im colourless needles. This acid is not easily soluble in water but easily soluble in ether and it may be very satisfactorily recrystallised from dilute methyl alcohol.

The melting point is 169°; at that temperature it melts to an opalescent liquid which does not become. transparent till 185°.

The elementary analysis gaye results corresponding with the com- position Cy) Hyp Os.

The originai substance differing from this by Cy Hy must, there- fore, be an ethyl-ester. To further prove this, 30 gram of the crystals were saponified with aqueous caustic potash and the resulting alcohol was distilled off. After treatment with dry potassium carbonate and rectification over anhydrous copper sulphate a liquid was obtained which boiled at 78° and showed all the properties of ethyl alcohol.

The potassium and silver salts of the acid were prepared and analysed. The potassium estimation gave 17.7 pCt. of K (theory requiring 17.6), the silver estimation gave 38.06 pCt. Ag., (theory requiring 37.9).

Tf a solution of the acid in ethyl alcohol is treated with hydrogen chloride, a product is obtained which melts at 50° and is identica! with the original ester. The methyl ester prepared in an analogous manner melts at 90°.

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The solution of the acid or its ester in chloroform absorbs two atoms of bromine forming an addition product.

The acid does not show either aldehydic, alcoholic or phenolic properties. Heated with hydriodie acid it yields alkyl iodide. A quantitative estimation according to ZeISEL gave an amount of silver iodide corresponding with 16.85 pCt. of methoxyl, theory requiring 17.4 pCt.

On oxidation with potassium permanganate in neutral solution, the ester gives off an agreeable odour resembling hawthorn, while an acid is also produced which proved to be identical with anisie acid. The oxidation of the acid in an alkaline solution proceeds more quickly; the odour of anisie aldehyde is also noticed here and a good yield of anisic acid is obtained. From this it follows that in regard to the side-chain the group OC Hz is situated in the para- position and in connection with the additive power the formula is

Ya therefore, most probably 1.4 Cg Ha ee CH — COOH » conse- quently that of p. methoxycinnamie acid.

The properties do indeed correspond with those recorded of this acid '). The only thing which is not mentioned is the peculiar behaviour on melting, so that I thought it necessary to prepare the synthetical acid for comparison purposes.

According to KNOEVENAGEL 2) it is obtained by condensation of anisic aldehyde with malonic acid under the influence of alcoholic ammonia. The acid prepared by this method also melted at 169° to an opalescent liquid which did not get clear till 185°.

VoRLANDER ®) obtained the ethyl ester of p. methoxylcinnamie acid by condensation of anisic aldehyde with ethyl acetate. This I also prepared and found it to be identical with the product obtained from “Kentjoer”, whilst the acid obtained from it by sapon- ification again showed the properties mentioned above.

I dare not, as yet, decide what may be the cause of this peculiar behaviour. Perhaps a polymeric body is formed, or else the acid exists in two liquid isomeric modifications *). By heating above the melting poimt, the acid is gradually decomposed with evolution of carbon dioxide, but if the decomposition already exercised some

‘) In Beilstein’s Handbuch it is erroneously stated that p. methoxyeinnamie agid cristallises in yellow needles.

2) Berl. Ber. 31 S. 2606.

5) Ann. der Chemie. 294, S. 295.

*) Compare: Rupo.e Scnenck, Untersuchungen iiber die krystallinischen Fliissig- keiten. Zeitschr. f. phys. Chemie XXV, 8. 837, XXVIIS. 167.

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influence during the determination of the melting point, this would be found lower on repeating the experiment, but this is, however, not the case.

By treating the alcoholic solution of the acid obtained from kentjoer with sodium amalgam p. methoxyphenylpropionic acid is formed, which melts at 102° and has already been described by Witt!). The methyl ester of methyl naringeninic acid *) prepared by the same chemist, which is identical with the methyl ester of p- methoxyeinnamic acid, melts at 90° just like the methyl ester obtained by myself, whilst its bromine-addition product showed the melting point of the methyl ester of dibromomethylparacumaric acid.

There cannot, therefore, be any further doubt that the crystallized substance which forms the chief constituent of the essential oil from Kaempferia Galanga L., is the ethyl ester of p. methoxycinnamic acid, a substance which had not yet been met with in nature and which now goes to increase the comparitively small number of known ethyl esters from the vegetable kingdom.

From the liquid portion of the oil I could separate in ad- dition to the above mentioned ester a small quantity of a terpene boiling at 160°—170° and a bluishgreen liquid boiling at 150° in vacuo (probably a sesquiterpene). There is also present an acid of a lower melting point which I am still investigating.

Pathology. — ‘On the durability of the agglutinative substances of the bloodserum.” By Dr. J. EK. G. VAN EmpeEn. (Commu- nicated by Prof. Th. H. Mac Ginuayry.)

Wipat and Srcarp*) and also AcHARD and Bensaupg*) have communicated that the bloodserum of patients suffering from febris typhoidea and that of animals, that had been rendered immune against the bacille of Esertu, keeps its agglutinative power undi- minished for many months; the agglutinines are so resistant that they do not perish even in mouldy and putrefying serum.

On the contrary I found that serum after some six weeks indeed

1) Berl. Ber. XX S. 2530.

*) Berl. Ber. XX S. 301.

*) Annales de I’ Instit. Pasteur XI p. 353.

4) Bensaupe: Le Phénoméne de VAgelutination des Mierobes, (Paris 1897).

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had lost a great deal of its agglutinative action: this at least was the case with sera from typhoid patients and from rabbits immunised against the bacillus aérogenes.

Also VAN DE VeELDE!) had observed an important decrease of the agelutinative titre of serum that had been put away.

Stimulated by my”) communication van Hourum®) investigated two sera that had been kept five and eleven months in sealed glass tubes in the dark and at the temperature of the room: the agglutinative power had not diminished.

The disagreement in the results mentioned above must in my opinion be caused by differences in the ways in which the sera had been kept.

The tubes of vAN Hourum had been sealed, but iy tubes — from which repeatedly a small quantity of serum was taken for testing pur- poses — were closed by cottonwool stoppers covered by pieces of paper or tinfoil.

Now the next experiment showed that the way of closing had a decisive influence on the fact whether the agelutinative power keeps constant or diminishes.

Serum of a known titre was kept in:

i tubes closed by cottonwool

9 ale

AN Bs - cork

Di lois 5 » sealing

4, filled with hydrogen and sealed Sees yy» earbon dioxide and sealed

Four months afterwards the agglutinative titre was determined again.

The agelutinative power of the serum in a// the sealed and corked tubes had remained wnchanged.

On the other hand in all the tubes closed with cotton wool the agelutinative power of the serum had strongly dimimished, notwith- standing the ciearly visible condensation — except in the case of one. This exception regards a soiled tube, in which the serum was covered by a layer of mould; this serum had also kept its power unchanged.

Conclusion. When the circulation of the air is hindered or suffi-

') Semaine médie, 1898 p. 379. *) Nederl. Tijdschr. van Geneesk. 1898 II p. $42. Zeitschr. f. Hyg. und Infect. XXX p.19. 4). sce mn a a 1898 II p, 841,

ciently limited, the bloodserum keeps its agglutinative power longer than when the access of air is free.

It lies at hand to think here of the influence of the oxygen in the air and in fact, experiments not yet terminated, support this opinion.

Now it is important to investigate whether the unstability of the other specific substances occurring in the blood, especially the anti- toxines must also be ascribed to the influence of the air. Perhaps that the efficiency of various medicinal sera will prove to be more durable, when they are kept in vacuo or in a neutral gas.

Geology. — “The Amount of the Circulation of the Carbonate of Lime and the Age of the Earth”. I. By Prof. Eva. Dunots. (Communicated by Prof. J. M. van BemMMELEn.)

In a similar way as water is continually passing into the atmos- phere, to return again to the earth, we find the carbonate of lime perform a circulation, as this matter is solved from limestone, and after having been carried to the ocean by the rivers, is there, through the agency of organic beings, again given back in solid state.

Even an approximative estimate of the amount of this circulation would be of considerable importance for geology, because we may regard it in connection with questions about the formation of that carbonate by decomposition of silicate rocks, and about the time required for its formation.

The results of an estimate as referred to, and some conclusions based on these results, are given in this paper, and in another paper I propose to present on the next occasion.

In investigating the amount of this circulation let us start from the carbonate of lime in the ocean.

The ocean contains in the deposits over its floor and floating about in the water such a vast amount of solid carbonate of lime, as remains of shells and skeletons of organisms, that, considering the perpetual movement, and the consequent mixing of the ocean “water, we may take it for granted that, under the existing pressure of carbonic acid and the actual temperature of the atmosphere, it contains carbonate and bicarbonate of lime in saturated solutions.

From experiments kindly made at my request by Dr. Ernst ConEn in collaboration with Mr. Raken, and the results of which, are communicated to the Academy at the same time as this paper, this

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proved really to be the case. According to W. Dirrmar!) 0.345 pCt. of all the salts of average ocean-water are carbonate of lime. The relative quantity of salts being 0.035, which may be considered as the average salinity of the ocean®), 1 litre of ocean-water would then contain 120.7 merms. Ca COs, of which 53.1 mgrms. CO, of normal calcium carbonate. From the average of 26 samples of water, taken from different parts of the ocean and at different depth, we may calculate 54.9 mgrms. CO; of normal calcium carbonate, and moreover 43.6 mgrms. of loose earbonic acid forming bicarbonate *). ToRNbE came to nearly the same results, as he found in the North Sea 53 mgrms. forming normal carbonate and 43 merms. of loose carbonic acid, forming bicarbonate *), per litre of water. With these the results of other analysts coincide. On account of the great uniformity of the chemical composition of the water of the ocean it may therefore be taken for granted, that in one litre of ocean water there are in solution on an average from 120 to 125 mgrms. carbonate of lime and of these about 100 mgrms. as bicarbonate. The investigation of Dr. Congn shows that in artifi- cial ocean-water, containing all the salts in the average quantity, as stated by Dirrmar, but no carbonate of lime, in a litre 125 mgrms, calcium carbonate could be dissolved from a surplus of suspended solid calcium carbonate by passing during a sufficient time a current of air, containing 0.00045 carbonic acid (a relative quantity in ac- cordance with the average).

We may say, therefore, that in the ocean-water the aforenamed matter exists as a saturated solution under the given pressure of carbonic acid in our atmosphere, and therefore we must take it that all the carbonate of lime which the rivers carry incessantly to the ocean is a surplus.

A considerable amount of carbonate of lime is often to be found in the matter carried in suspension by large rivers to the ocean. Some analyses relating to this and extending over longer periods of time may be mentioned here. C. Scumipv.®) found in twelve monthly determinations for the relative quantity of calcium carbonate in the suspended matter of the Amu-Darja from 17.0 to 19.6, on an average

1) Neport on researches into the composition of ocean water collected by H. M.S. Challenger. Challenger Reports, Physics and Chemistry. Vol. £. London 1884, p. 204.

*) Dirrmar |. c. p. 201.

SVE Cy pep Pal

*) Berichte der Norwegischen Nordmeer-Expedition. Abt. Chemie, referred to by JoausLAWsKI, Handbuch der Ozeanographie. Stuttgart 1884. Bd. L, p. 139.

5) ©. Scumipr und I, Dorranpr, Wassermenge und Suspensionsschlamm des Amu- Darja, Mémoires Acad. imp, St. Pétersboure (7). Tome 25. n°. 3. 1878, p. 31.

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18.3 pCt., from which may be calculated an average quantity of 41.7 mgrms. of that salt per litre of water. BALto!) found that from the 300 mgrms. suspended matter contained in a litre of Danube-water, 5.53 pCt. is lime combined with carbonic acid, being 9 pCt. or 27 mgrms. CaCO, per litre of water. The water from the Blue Nile near Khartoum, as the river was low or high, contained per litre 16.9 to 62.1 mgrms. solid calcium carbonate in suspension.”) The clay which the Nile deposits in its delta, according to different analysts contains 3.72 pCt. of this salt *), so, that taking into account the average quantity of solids in suspension of 458 mgrms. per litre *), the water of the Nile would have contained at the delta an average of 17 mgrms. calcium carbonate in suspension.

Where thus in many of the large rivers there is always a surplus of cal- cium carbonate, which may easily be acted upon by the dissolving agents, it is obvious that in these river waters too the solution must be saturated. Whereas however in the ocean-water this salt, as regards its absolute quantity, is of very little account in comparison with the other salts, in the water of such like rivers it constitutes nearly the half ofall the salts which here form a much weaker solution.

According to a combination by Sir Jonn Murray °) of the analyses of 19 large rivers one litre of river water contains on an average 186 mgrms. of total sslids in solution, of which 79.6 mgrms. are calcium carbonate.

From the experiments of ScHL@siNG °), so highly important for geology, made in a similar way on pure water, as the recent expe- riment of Dr. Ernst CoHEN on ocean-water, by bringing a large quantity of calcium carbonate in suspension in long contact with air, containing a constant relative quantity of carbonic acid, it follows 7) that in one litre of pure water by common air, the pressure of carbonic acid being 0.0005, and 16° C temperature, 74.6 mgrms. car- bonate of lime are soluble. The solution takes place for about 13.1 mgrms.

1) Chemische Untersuchung des Wassers des Donaustromes bei Budapest. Berichte der Deutschen Chemischen Gesellschaft. 1878, p. 444.

*) A. Cutxu, Le Nil, le Soudan, Egypte. Paris 1891, p. 25.

8) C. Scumupr, |. ¢., p. 40.

4) CHELU, |. c., p. 203.

®) On the total annual rainfall on the land of the globe, and the relation of rainfall to the annual discharge of rivers. Scottish Geographical Magazine. Vol. 3. Edinburgh 1887, p. 76.

6) Tu. ScuiesinG, Sur la dissolution du carbonate de chaux par lacide carbonique. Comptes rendus de l’Académie des Sciences. Paris. Tome 74. (1872), p. 1552—1556, and Tome 75 (1872), p- 70—73.

*) L.¢., p. 1555.

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as normal carbonate, independent of the pressure of carbonic acid and very little dependent on temperature, for a greater part however, namely 61.2 mgrms. as bicarbonate, the lime being combined witha double quantity of COs. The quantity of the bicarbonate thus formed depends, for a given temperature, on the pressure of carbonic acid. The value of the pressure of carbonic acid and of the quantity of carbonate forms two geometrical series, but the ratio of the former is greater than that of the latter series. If the pressure of carbonic acid were’ 0.0008, i. e. more than one and a half the actual pressure, the quantity of bicarbonate formed would be 73.2 mgrms. per litre of water. At a pressure of 0.05, i.e. the hundredfold of the pressure of carbonic acid in the atmosphere, the quantity of bi- carbonate only increases to 349,3 mgrms. per litre of water, that is a little more than five times and a half (5.7). Generally stated the quantity of bicarbonate formed depends in such a way on the tension of carbonic acid, that, if that tension is called 2, the quantity

; : 7p 0;37866 of the bicarbonate y Se Cer

So if the pressure of carbonic acid rose to 700 times that in the atmosphere the quantity of carbonate of lime dissolved in the state of bicarbonate would be only about twelve times as great as at the actual pressure of carbonic acid in the atmosphere, and that of the carbonate dissolved in both states, as normal carbonate and as bicar- bonate, only about ten times as great as under the actual condition of carbonic acid pressure.

Scun@sinc found moreover, that with every degree of variation in the temperature, the quantity of the bicarbonate dissolved varies about 1 pCt., viz: it rises as the temperature falls, and it diminishes as the latter rises.

The figures given by Scuiasine@ for the quantity of the carbonate of lime dissolved at the pressure of carbonic acid in the atmosphere and 16°C. temperature come so near the average quoted quantity of that matter in river water, which on an average has about the same temperature (the mean temperature at the surface of the earth being

5° C), that it may be taken for granted, that those large rivers keep the carbonate of lime in solution in similar way as in pure water, partly as carbonate, for the greater part however as bicarbonate, and that the quantity of that double salt in it is depending on the pressure of carbonic acid in the atmosphere.

The number of analyses, from which Murray drew the above mentioned averages seems to be sufficiently large for the purpose, never- theless, when the existing reliable analyses of river water are compared

(a7)

with one another, it appears that these deviate rather strongly, and that the average has only this value, that on the whole the relative quantity of dissolved carbonate of lime oscillates about saturation with that salt in pure water under the pressure of carbonic acid in the atmosphere. In some cases the relative quantity observed remains below it, but mostly it rises higher.

In one and the same place the relative quantity of carbonate of lime dissolved in river water varies according to the water mark. If the river rises the quantity of suspended matter per litre of water increases, but the quantity of dissolved matter, and among these of carbonate of lime diminishes. A few examples may explain this.

According to the determinations of Voni') the quantity of carbonate of lime in the water of the Rhine, taken from the same place, a little above Cologne, varied from 52.37 mgrms. per liter at high water mark, to 109.37 mgrms. at low water mark, thus in the ratio 1 to 2. This diminution of the relative quantity of dissolved matter in general and of carbonate of lime in particular, when the discharge of water is greater than usual, is a fact generally observed, which, among others, has been sufficiently proved from long and reliable observations made on the water of the Danube by Bato?) and WoLFBAUER®*) and from the water of the Meuse by Spring and Prost. WoOLFBAUER found‘) that the relative quantity of suspen- ded matter in 23 determinations, made during a year with intervals of, on an average, 16 days, proved to vary from 9.6 mgrms. as a minimum to 331.3 mgrms. as a maximum per litre of water, which two numbers stand to each other in the ratio as 1 to 35, whilst at the same time with the given minimum of the quantity of suspended matter a maximum of dissolved matter of 207 mgrms. was obtained, and at the same time with the quoted maximum of the quantity of suspended matter a minimum of dissolved matter of 130 mgrms. per litre, which two numbers stand to each other as 1.6 to 1. Whereas during low water the Blue Nile near Khartoum, according to Cust *) earries only 156.3 mgrms. and during high water 1673.4 mgrms. of sus- pended matter per litre of water, so in the ratio 1 to 10.7, the

1) H. Vout, Ueber die Be:tandtheile des Rheinwassers bei Céln. Dincurr’s Poly- technisches Journal. Bd. 199. 1871. p. 311 sqq. ;

*) M. Bauto, lic. p. 441—445.

*) J. F. Worrsaver, Die chemisthe Zusammensetzung des Wassers der Donan vor Wien im Jahre 1878. Sitzungsberichte der Math. Naturw. Classe d. Kais, Akad. Wiss. Wien. Bd. 87. (1887), p. 404—424.

4) lc. p. 414.

2) pleiG-\p-2o—

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quantity of dissolved matter during high water was at the same time even a little higher than during low water, it rose namely from 201.4 merms. to 232 mgrms. per litre. The total solids in solution in the water of the Meuse at Liege attained during a year a maximum at low water mark of 279 mgrms. and a minimum at high water of 86.2 mgrms. per litre, giving a ratio of a little more than 3 to 1). For the matter in solution in the Arve the maximum is to the minimum in the ratio 2.5: 1, whilst for the suspended matter this ratio was 5000: 1. *).

However those extremes are only attained on one single day. Comparing longer periods of time we find the differences far smaller. For the Elbe in Bohemia the minimum quantity observed in 22 determinations, made during a year, amounted to 20.3 mgrms. CaO, the maximum quantity to 45 mgrms. per litre of water, and the quantities of the other substances showed similar unimportant varia- tions, °) whilst those of the suspended matter*) varied from 1.13 to 756.01 mgrms. per litre. WOLFBAUER corroborated moreover the fact, which had already repeatedly been noticed, that, no matter how much the absolute quantities of the dissolved substances may vary, the mutual ratio of the components remains almost unchanged °). Something similar is also known of the substances in suspension in the river water, and appears clearly from the twelve monthly analyses of the suspended matter in the Amu-Darja, published by Scumipt “). Silicates and quartz for instance varied in it only from 76.2 to 79.86 pCt. Hence follows, which is important for the following considerations, that the results of a single analysis may be applied to determinations of the absolute quantities of the same river.

Besides those variations of the relative quantity of suspended matter depending on variations of the water mark in connection with time, and which, as is generally observed, can in large rivers

') W. Serine et EK. Prosr, Etude sur les eaux de la Meuse. Annales de la Société géologique de Belgique. Tome 11 (1S83—1884). Liége 1883. p. 175.

*) B. Bakrr, Les eaux de Arve. These. Genéve 1891, p- 59.

3’) PF. Unirx, Beobachtungen iiber die Bestimmung der wihrend eines Jahres im Profile von ‘Tetschen sich ergebenden Quantititsschwankungen der Bestandtheile des Hlbewassers und der yon letzterem ausgefiihrten loslichen und unléslichen Stoffe. Abhand. kon. bohmischen Gesellschaft der Wissenschaften. VI. Folge, 10 Band. Math. Naturw. Classe. N°, 6. Prag 1880, p. 31.

‘) Ibid. p. 28.

5) lic. p. 415.

6) icp ol.

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at most amount to the ratio 1: 3, and this very transitorily, varia- tions have been stated of the relative quantity of carbonate of lime in solution in the rivers according to space. Some rivers have a lower average quantity of carbonate of lime than others, though with most large rivers those differences are not great, at most amount to about the same ratio as the temporary variations, which are of very short duration.

But also in the same river, and even over small distances, the quantity may be a little different. That was apparent again from the observations of Vout. The water taken on the same day, but from three different points, namely above, in and below Cologne, as well during high as low water mark, proved to grow richer in carbonate of lime in its course through the town.

The quantity of carbonate of lime, in milligrammes, contained in one litre of water from the Rhine was,

during very low watermark, during high watermark, on Oct. 21st 1870, on Nov. Sth 1870, above Cologne 109.37 52.37 : in Cologne 115.78 68.92 below Cologne 123.44 108.68

This increase is evidently to be accounted for by the influence of organic matter, combinations of carbon, which pollute the water and are consequently oxydized in it, and which, as long as they remain there, keep more carbonate of lime, in the state of bicarbonate, in solution than the carbonic acid of the atmosphere, absorbed in the water, would alone be able to do. That really the organic substances in the river water are soon oxydized is evident from the fact, stated by Utuix, that those substances soon diminish in water samples kept standing for some time. From the observations made by him ') is to be derived that on an average in 24 hours 3.5 pCt. (from 1.7 to 5.4 pCt.) of the organic matter is decomposed. Bacteria and algae are the principal agents and contribute mostly to the so called self-purifying of the rivers.

Very instructive in this respect are the analyses of the water of lakes as they have been stated principally by DeLtysecque. From these it has been made evident, that the water of lakes fed by rivers and rivulets in a region rich enough in limestone, takes in general the more carbonate of lime in solution in proportion to the surface

es peabe

Proceedings Royal Acad, Amsterdam, Vol. ILI.

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of the lake being smaller. 'The increase of the circumference indeed is less than that of the surface, it increases in general as the square root of the surface. A lake, whose surface for instance is the ninth part of that of another lake, has, if the two are uniform, still the third part of its surface. Moreover the depth also often decreases with the length and breadth, though by no means in the same propor- tion, so that the volume of water of a small lake in comparison with its circumference is a good deal less. Now as organic matter principally enters the Jakes from the circumference, it is clear that by the continually flowing source of carbonic acid, which this matter produces by its decomposition, the quantity of carbonate of lime, in the state of bicarbonate, in the water of these lakes under otherwise similar circumstances is greater in proportion to the lakes being smaller. Foret!) had already pointed out that in the mud at the bottom of a lake the quantity of organic débris is the greater in proportion to the lake being smaller. In the following lakes, inves- tigated especially by DELEBECQUE?), all draining the same limestone regions, the influence of size is clearly to be recognized.

Surface, in K.M2. Volume, in M’. CaCo,, in mgrms. per L, Lake of Geneva *) 582.40 88920000000.0 72.3 Lac du Bourget 44.62 3620.0 96.0 > d’Annecy 27.00 1123.5 123.7 >» d’Aiguebelette 5.43 166.6 126.4 > de Paladru 3.90 97.2 150.9 » de Nantua 1.41 40.1 154.5 > de Sylans 0.50 4.8 152.6

Something similar is to be observed concerning rivers. At the same length a large river is less liable to pollution than a smaller one. The distance from Geneva to Lyons is less than that from lake Ontario to Vaudreuil (above Montreal), yet the Rhone to Lyons having the same length of bank and containing only !/,; of the water of the St. Lawrence river, takes more organic matter and in consequence of this the Rhone at Lyons*) held in winter 150, and in summer 100 mgrms. CaCOs per litre in solution, the St. Lawrence (March 30th)

1) F. A. Foren, Le Léman. Etude limnologique, Lausanne 1895. Tome II, p. 134.

*) Archives des sciences physiques et naturelles. (3). Tome 27, Geneve 1892, p 569—570 and p. 134. — Tome 28, p. 502.

*) From Foren and DeLesrcgue (quoted afterwards).

*) According to Boussincauur and Pasaurer, quoted by G. Biscuor, Lehrbuch der chemischen und physikalischen Geologie, 2 Aufl. Bd. I, Bonn 1863, p. 272.

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only 80.3 mgrms. '), whereas in the Jarge lakes, whose outlets they are, there is only about as much Ca CO, dissolved as in pure water.

Freshwater lakes with an outlet are of great importance in consid- ering these questions, on account of the rather constant composition of their waters, which is a consequence of their volume being very large in comparison with that of the discharge of the affluents and of the outlet. The lake of Geneva contains about 11 times as much water as the yearly discharge of the Rhone at Geneva, lake Ontario 10 times as much water as is flowing every year through St. Lawrence river; the water of the lake of Annecy is on an average renewed in 3.3 years, and that of the lake of Paladru in 4 years *). So one single analysis of their waters has already a great value. The quantity of carbonate of lime in the water of some lakes must therefore been spoken of somewhat more in extenso.

Very large lakes, in the drainage area of which much limestone occurs, receive relatively to the bulk of their waters so little organic matter, and their relative quantity of carbonate of lime is therefore so greatly influenced by the pressure of the carbonic acid in the atmosphere alone, that it agrees nearly with that which ScuLa@sinG stated for pure water. From 11 reliable analyses of the water of the lake of Geneva, which varies only a little in composition in consequence of the mixture being temporarily and locally less perfect, or by variations of the temperature and the pressure of the air, contains per litre in 175 mgrms. dissolved solid matter 74.9 mgrms. calcium carbonate *). In the opinion of DELEBECQUE *) the first named number is not right; as average of 33 determinations, quoted by him, we find 169 mgrms. dissolved solid matter per litre of lake-water, in which, therefore, 72.3 mgrms. calcium carbonate are contained. The volume of the water in the lake of Geneva being 89 K.M®., at an average yearly discharge of the Rhone at Geneva of 8 K.M*., the water remains in the lake, as has been already stated, for about 11 years. Therefore organic matter which the rivers carry into the lake and which enters it from the shore can hardly have any noticeable influence on the quantity of the calcium

1) According to T. S. Hunt in: Geology of Canada. Geological Survey of Canada. Reports of progress from its commencement to 1863. Montreal 1863, p. 567. Also in Philos. Magazine (4). vol. 13, p. 239. The sample was taken at the Point des Casea- des near Vaudreuil, on the 30th of March 1863.

>) Foret, |.c. Tome I, p. 446, and DeLesecaue |. c.

5) Foret, Le Léman II, p. 587.

4) A, DELEBECQUE, Les lacs francais. Paris 1898, p. LYL and 197-198.

4*

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carbonate. In fact the water of the lake of Geneva contains only little organic matter, on an average 5.5 mgrms. per litre '), whereas rivers according to MurRay’s statement contain on an average 19 mgrms. In the water of the Danube WoLFsauer found, it is true, only 5.6 mgrms., there is however still suspended organic mat- ier, according to BALLo 20 mgrms. per litre, of which hardly any is to be found in the lake of Geneva. ULLik ®) stated during one year’s observations, that the organic matter in the water of the Elbe got below 6 mgrms. per litre on three days only, he found for the mini- mum 5 mgrms., and for the maximum 22.6 mgrms. per litre.

The lake of Geneva, therefore, contains, in distinction from other lakes, which are smaller, but also situated in a limestone region, hardly more carbonate of lime in solution than that corresponding to the tension of carbonic acid in the atmosphere. If with DELEBECQUE we take that the latter contains 0.00029 of its volume carbonic acid, the average pressure of the air on the lake of Geneva being 730 mm., we find for the tension of carbonic acid 0.000424, and from the formula of ScHL@sING we calculate that 70.5 mgrms. carbonate of lime can be dissolved, as normal salt and as bicarbonate, in 1 litre of pure water at 16° C temperature, therefore at the average temperature at the surface of the lake of Geneva of 9.6° C., 75 mgrms.

At the mean relative quantity of carbonic acid of the atmosphere on the northern hemisphere of 0.000282 Vol. pCt.*) and the mean pressure of the air, where the rivers flow into the ocean, of 762 mm. we find that 70.8 mgrms. calcium carbonate (in both states) are soluble in 1 litre of water. *)

The great North American lakes, whose waters flow to the ocean through the St. Lawrence river, have 425 times the surface of the lake of Geneva and about 500 times its volume, and lake Ontario, the water of which flows directly into the St. Lawrence river, has 34 times the surface and 40 times the volume of the lake of Geneva. The St. Lawrence river discharging yearly 364 K.M®. of water, lake Ontario would empty in about 10 years, if the water were rot continually renewed. Under these circumstances, even on account of one single analysis it may be taken that the water of the St.

1) Foret, Le Léman, IL p. 615.

2) Tisie:, -p: Sl.

‘) A. Minrz et E. Austy, Recherches sur Vacide carbonique de Vair. Mission scient. du Cap Horn 1§82-1883. Tome ILI. Paris 1886, p. A. 82.

') DELEBEcQuE (Les lacs frangais, p. 218) arrives at different results by erroneously substituting the relative volume for the relative pressure.

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Lawrence above Montreal, to where only one single insignificant little river joined, and has only been in contact with cambrian and cambrio-silurian crystalline rocks, can only be very little richer in carbonate of lime than the water of the lake itself. Near Vaudreuil it contained in a litre, according to the modus of calculation, from 80.3 to 80.8 mgerms. carbonate of lime!). The relative quantity of that salt in the lake-water will therefore not differ greatly from that of Geneva.

The water of lake Peipus in Russia, another large fresh water basin (having 6238 KM. in surface and 12 M. as its greatest depth) contains, according to the analysis of C. Scumipt*), in summer 67 mgrms. CaCO; per litre.

The water of the lake of Gmunden or Traunsee in Upper Austria (having a volume of 2.3 K.M*., and through which flows the Traun keeps in solution 64 mgrms. calcium carbonate per litre °).

In the drainage area of all the above named lakes limestone is largely represented. Moreover in the mud on their bottoms there is much carbonate of lime, and the waters of the affluent rivers carry on an average more of that salt in solution with .them than the waters of the lakes contain*). In the mud of the lake of Geneva °) there is found a mean percentage of 27.8,a mini- mum of 14.9 carbonate of lime, that of the lake of Bourget*) contains 55.5 pCt., of Annecy 28 to 79 pCt.; of Aiguebelette 29.7 pCt., of Paladru 84.7 pCt., of Nantua 56.3 pCt., of Sylans 73 pCt. °).

It is therefore evident that those waters must be satured with Ca COs.

In regard to the analyses of river water I refer to Brscnor and Rotu in the first place’). Some reliable and especially important analyses may still be quoted here.

According to two analyses of Von *), one during high and one

1) T. S. Honr in: Geology of Canada. Montreal 1863, p. 566.

2) Bulletin de Académie impér. des Sciences St. Pétersbourg, T. 16. 1871. p. 192.

5) R. Goperrroy, Ref. in Jahresbericht iiber die Fortschritte der Chemie ftir L882, p- 1623.

*) According to Durarc (le Lae d’Annecy, Archives des sciences physiques et naturelles (3), Tome 31. Gentve 1894, p. 197) the water flowing through 13 rivulets into the lake of Annecy contains on an average 199.1 mgrms, CaCO, per litre, that from the lake itself 50 mgrms. less. The surplus is consumed by algae, whilst calcareous, tufa is formed.

5) Caleu'ated according to 15 analyses mentioned by Foren (Le Léman, L. p. 122 - 128).

*) Archives, Genéve. Tome 27. p. 573 and Tome 31. p. 197.

7) G, Biscnor, 1. ec. — J. Rorn, Allgemeine und chemische Geologie. Berlin 1879, Ba. Lv, 457 saq.

) Le,

( 54 j

during low water mark, of the water from the Rhine, taken above Cologne (in and below Cologne a temporary increase of the quan- tity of carbonate of lime takes place) it contains a mean of 80.8 mgrms. CaCO, per litre. BiscHor found during low water at Bonn 94.6 mgrms., GuwninG !) in February 1862 at Arnhem 87.5 mgrms. Some other analyses of water from the Rhine yielded figures slighly higher, for instance those of FreyraG (above Cologne in 1853 and 1855) 132.3 and 134.1 mgrms. and of Sainte Cratre Devine (1848 at Strassbourg) 135.6 mgrms. per litre (these analyses all quoted by Vout).

The determinations of the matter in solution in the Meuse at Liege, daily made during a year by Sprine and Prost, and the analyses of those, collected in 13 periods differing according to the water mark, show that the Meuse contains on an average 90 mgrms. Ca CO; per litre of water *).

According to the analyses by WoLFBAUER of 23 samples of water taken during a year with intervals of about 16 days, the water of the Danube above Vienna contains on an average 97.9 mgrms., according to one analysis of Batno at Budapest (in the middle of November) 88.7 mgrms. carbonate of lime per litre.

The Embach above Dorpat and the Welikaja at Pskow, which- both flow into lake Peipus, contain in summer, during low water, 88 resp. 82.5 mgrms. dissolved carbonate of lime per litre of water %).

The Syr-Darja (May 1878°, according to an analysis by C. Scumipr *) contains 86.4 mgrms. Ca COs per litre water.

The Blue Nile near Khartoum has on an average, from an obser- vation at high and another at low water, 77.5 mgrms. carbonate of lime in a litre of water *).

From the analyses of water of the Nile near Cairo published by Cutitu") it appears, that on an average (from twelve, monthly repeated, observations) among the dissolved matter 42.5 merms. Ca O

1) J. W. Guanine, Onderzoek naar den oorsprong en de scheikundige natuur van eenige Nederlandsche wateren. Utrecht 1853, p. 66. Also in Jcurnal fiir praktische Chemie, Bd. 61 (1854), p. 139.

*) Calculated from the statements (I. c. p. 208 and 212) of the solid matter in solu- tion carried during a year and the yearly discharge of water. — Four analyses of water from the Meuse by CaanpELon (quoted by Brscnor) yield a mean of 86,3 mgrms., one of Gunnine (l.¢.) at Grave 72 merms. per litre.

*) C. Scumrpr in Bulletin de l’Académie imp. des Sciences St. Pétersbourg 1875, Tome 20, p. 134.

*) Mémoires de l’Académie imp. des Seiences St. Pétersbourg. (7). Tome 29, 1881, p. 25.

*) Cni&nu, |. c. p. 25,

©) Thier: 277,

(55 ) are found, which would correspond to 96.6 calcium carbonate pér litre. Part of this lime, however, is combined with sulphuric acid, in what quantity cannot be stated from the other results of the analyses, which seem to be stated wrongly.

From the water of the Mississippi, which, being a very large river, with a drainage area equal to 16 times that of the Rhine, would be of great importance, I am acquainted only with two analyses, one by AveQquin!) and another by Jones?). According to Avequin, in August 1856, 1 gallon of water from the Mississippi above New Orleans (at Carrolton) contained 7.307 grains of carbonate of lime and carbonate of magnesia; according to JONES near New Orleans 1 litre contained 92.8 mgrms. carbonate of lime and no magnesia. If now according to the usual ratio we reckon that one United States gallon is equal to 57750 grains it would follow from the analysis of the first named chemist that one litre of Mississippi-water then contained 126.5 mgrms. Ca CO; + Mg CO, in solution. If taking however with Metnuarp ReapDeE that one gallon is equal to 56000 grains then the number for the dis- solved carbonates would be 130.4 mgrms. Carbonate of magnesia being in every case only present in small quantities, the two latter num- bers for the carbonates appear to agree pretty well with the result of the analysis of AVEquin. According to the values for the yearly discharge of carbonate of lime and the yearly discharge of water of the Mississippi, quoted by Russet, a quantity of 75.5 mgrms. per litre is to be calculated °).

The average quantity of carbonate of lime of twenty rivers in North America, nearly all of which, however, are of very small size, and many draining regions poor in or even deficient of limestone, is according to RussELL 56.4 mgrms. per litre *).

Among the smaller rivers there are many, flowing over limestone or taking up the water of sources situated in limestone, which are very rich in dissolved calcium carbonate, partly because they contain spring water, not yet sufficiently ventilated, which has taken up carbonic acid under a higher pressure, and partly on account of

1) A. Avequin, Journ, Pharm. (3). Vol. 37 p. 258. (1857). Qnoted by T. Mentarp Reape in American Journal of Science, (3). Vol. 29. (1885), p. 251.

2) W. J. Jones, Report La, St. Board of Health 1882, p. 370, qnoted by J. ©. Russet in: Geological History of Lake Lahontan, Monograph of the US, Geological Survey, Vol. Xl. (1885), p. 176, Table A.

3) Le. p. 175. le, p. 174,

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their being more polluted by organic matter. In their farther course they Jose much of their dissolved carbonates.

Here may still be remembered the 9 analyses of Thames water, quoted by Brscnor'), which all show a high quantity of calcium carbonate, namely from 115.6 mgrms. to 205.4 mgrms. per litre, and also those of the water of the Seine at Paris, according to Pog- GIALE*) by whom during a year an average of 115 mgrms. was found, and according to Sv. Charge Devinie, who found 163.5 ngrms. per litre in the water of the Seine below Paris. These results indicate again the increase of the quantity of carbonates of lime in consequence of pollution of the water by organic matter °).

Some rivers, which flow for the greater part of their course over erystalline silicate rocks, and of which only few are of-large size, are on the contrary poor in calcium carbonate.

From the water of the Rio de la Plata, a river which, as to the size of its drainage area, is only little inferior to the Mississippi, and which discharges more water, there exists according to MELLARD ReaDE*) “a very exhaustive series of observations and analyses,” | made by Juan J. J. Kyus, during 1872 and 1873 and the results | of which he has published in a pamphlet of 11 pages in 1873 at | juenos Ayres, which to my great regret I have neither been able to procure, nor to read. As average quantity of solid matter in

solution of fourteen analyses of water taken at different times, from . April to June, in the neigbourhood and above the city of Buenos Ayres,

MeELLARD ReaveE gives !/g.43, and from two analyses in September Y/si95- If we take the sixteen analyses to be of equal value we geta |

mean of 1/g93 or 166 mgrms. per litre of water, figures which agree very well with those observed in most of the other large rivers. Starting from the last stated mean we may compute from the results of analyses of Rio de la Plata water, published by Kyzz elsewhere ®*), | that it keeps in solution only 23 mgrms. carbonate of lime per litre.

The Amazone, according to the analysis of one sample by P. S.

1) J. c. p. 273 and 274. 2) Jahresber. der Chemie, 1855. p. 521.

*) H. M. Wirt, On the variation in the chemical composition of the Thames water. Philos. Magaz. (4). Vol. 12. London 1856 p. 114—122, published a number of analyses of the water of the Thames at Kingston and at Chelsea, according to which e.g. with a relative quantity of 137.3 mgrms. calcium carbonate, 23.3 merms, of organie matter were determined.

‘1 ic. p. 292,

®) Chemieal News, Vol, 38 (1878), p. 28,

(89 FRANKLAND!), keeps as little carbonate of lime in solution, 27.5 mgrms. per litre.

The Dwina above Archangel has, according to one analysis by ©. Scumipt, only 20.2 mgrms carbonate of lime ina litre of water °).

As to smaller rivers, for instance the water of the Hudson, cal- culated from an analysis by C. F. CHANDLER *) keep 42 mgrms. calcium carbonate per litre in solutions, and that of the Delaware, according to an analysis by H. Wurtz of a sample taken from the reservoir at Trenton *), 25 mgrms. calcium carbonate per litre. Such rivers poor in dissolved calcium carbonate are mostly of minor importance as to their discharge of water.

In regard to the rivers, in whose drainage areas limestone rocks abound, it appears from the above stated facts and considerations, that in the water which they discharge into the ocean, dissolved carbonate of Jime is found in a ratio which on the whole is some- what higher than that which would exist, if it were under the influ- ence of the carbonic acid of the atmosphere only and it contained a surplus of solid carbonate of lime. In fact limestone being spread all over the earth, we may take for granted that the greater part of the river water flowing into the ocean has had an opportunity to get saturated with carbonates of lime. Those rivers in general contain during low water mark rather more carbonate of lime, whereas during high water mark the quantity of this matter may fall somewhat below the saturation-point of pure water. On the other hand some large and many small rivers, draining areas which are poor in or deficient of limestone, keep considerably less carbonates of lime in solution.

It appears, therefore, that we cannot be far from the truth if we assume that the water which the rivers carry to the ocean keeps on an average as much carbonates of lime in solution as pure water ean contain, thus taking that the influence of the carbonic acid de- veloped by the decomposing organic matter is counteracted by that of the temporary diluting during high water mark, and that of the river waters flowing directly into the ocean, which are poorer in carbonate of lime. The surplus which the organic matter gradually develops in the river-water can never cause the pressure of carbonic

1) Quoted by MeExtarp Reape, |. c, p. 295.

*) Bull. Acad. imp. St. Pétersbourg. Tome 20 (1875), p. 152.

4) Report of the American Public Health Association. Vol. I, p. 542=543 (quoted by I. C. Russevt, l.c. p. 176, Table A).

*) Also quoted by Russe, ibid,

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acid to rise high, as is already evident from the fact that in summer the quantity of calcium carbonates dissolved is by no means always greatest, the greater absorbing power at lower temperature is pre- valent as a rule. The highest surplus is found in such profusely polluted waters as those of the Thames.

The total quantity of the water, which the rivers discharge yearly into the ocean has repeatedly been estimated, by K. Ritcius ') at 28000 K.M, by A. Woerrkorr’) at 18800 K.M.%), by Sir Jonn Mcrray*), from the most reliable data, at 27000 K.M%. and DE LAPPARENT and Penck agree with Murray.

According to Murray’s figures, if at the same time we take that the water which the rivers discharge into the ocean contains on an average 74 mgrms. of carbonate of lime per litre, we may calculate that two billion (i. e. 2 x 10!) KG. of carbonate of lime, which as solid rock would have a volume of about three fourths K.M%, forming a cube with more than 900 M. side, are yearly carried to the ocean in dissolved state.

Considering now that the ocean water is saturated with carbonate of lime, that the quantity of ocean water does not undergo percept- ible changes, and that moreover it is wholly inadmissable that this yearly surplus should serve only or for a large part to increase the calcium sulphate of the ocean, the latter salt being found in it only in about the tenfold quantity of the carbonate of lime, and therefore only in 800.000 times as great a quantity as that of the aforesaid yearly surplus itself; these two billion KG. of carbonate of lime must pass every year from the liquid into the solid state. That this hap- pens entirely, or at least principally, by the agency of organisms and as we now know for the greater part indirectly through calcium sulphate, is of no account here. That on the other hand this carbon- ate of lime, which in the ocean became svlid again, will once be elevated by the endogene forces of our planet and changed into land, brought again into solution to take the same way, is to be concluded as well from the fact that we find already mighty strata of limestone in the archean formations and in all later formations, as from the fact that all rivers and lakes in whose drainage areas no limestone reeks are found, contain only little carbonate of lime

") La Terre. Vol. I. 4me Edition, p. 514—517, *) Die Klimate der Erde, Jena 1887. p. 50. a) RAC upand

*) A. De Larparent, Traité de Géologie, 4me Edition, Paris 1900, p. 232. ~ A, Pexek, Morphologie der Erde. Theil I, p. 273,

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in solution. The instances already quoted by Biscnor of the Dee at Aber- deen, whose sources are situated in crystalline silicate rocks (granite) and which contained only 12.2 mgrms. calcium carbonate per litre of water and of the glacier-rivulet Méll at Heiligenblut and Oetz at Vent, which, flowing over crystalline shists, proved to contain only 8.4 and 4.5 mgrms. per litre resp. of that salt in solution, whereas on the contrary the Lutschine at Grindelwald, having limestone for its bed, contained even close at the glacier as much as 40.5 mgrms. ') may here be mentioned as a proof that by far the greater part of the calcium carbonate, which the rivers carry to the ocean originates from limestone mountains, which have been formed from calcium carbonate made already solid in the ocean in former times.

The Croton River (supplying water to the City of New-York), draining a region of archean rocks, has only 87.2 mgrms. of dissolved matter and 28.5 mgrms. calcium carbonate in a litre of water !).

The Ottawa, receiving the greater part of its waters, flowing through many small lakes, from a region of crystalline rocks, and also draining great areas of forest and marsh, contains in solution 24.8 mgrms. calcium carbonate and 16.4 mgrms. of organic matter per litre of water *).

The water from the Upper Bann in Ireland, before reaching Lough Neagh has been flowing over 50 KM. of granite, and contains only 17.7 mgrms. CaCOs per litre °).

The water of the Elbe, on reaching Tetschen, near the northern frontier of Bohemia, has been in contact chiefly with crystalline silicate rocks and sandstones, and only in the silurian basin of Prague and in the Cretaceous rocks of the northern part of Bohemia also with some limestones. It contains, according to the deter- minations, made by ULuiK in 22 periods during a year, only 67.5 mgrms. matter in solutien per litre (besides the organic substances), of which 50 mgrms. are calcium carbonate. That is not more than about a half of what a river so profusely polluted with organic matter as the Elbe at Tetschen would be able to take, if its waters

1) Ii. ce, p: 275.

2) J. D. Dana, Manual of Geology. Fourth Edition. New-York 1896, p. 121, quoted from E. Water, water supply of New-York City, 1881 and C. VF. CHanpier in Johnson’s Cyclopedia. Vol. 1V. The water was taken from the reservoir supplying New-York City, itself supplied from the upper part of the drainage area of this small river.

8) T. S. Hur in Geology of Canada. Geological Survey of Canada. Report of Progress from its commencement to 1863. Montreal 1863, p. 566. “The water was taken on the 9th of March at the head of St. Anne’s Lock, and was remarkably free from any sediment or mechanical impurity.”

‘) HopcEs, Chemical News, Vol. 30 (1874), p. 102.

( 60 ) eame so largely in contact with limestone as is the case with most of the large rivers. And so in the suspended matter there are hardly any traces of solid carbonate of lime, indeed less than 1 mgrms per litre of water ').

The contact with limestone rocks of the waters of the Moldau, a large tributary to the Elbe, having been still less above Prague, they contain even less than half the calcium carbonate of the Elbe at Tetschen 2).

According to an analysis of water from the Uruguay River at Salto by Kyue (l.c.) it kept in solution per litre 10 mgrms., according to another analysis by R. ScuorLLer®) of the water from the same river below Fray Bentos 16.2 mgrms. calcium carbonate. The drainage area is almost entirely taken by sandstone rocks, which are very poor in lime.

In six little lakes of the granite region of the Plateau Central of France DELEBECQUE found only 18 to 77 mgrms. solid matter in solution in a litre, on an average 37 mgrms.*), whereas 14 lakes, equally small, in the département du Jura, where limestone rocks abound, held 108.6 to 195.6, on an average 147 mgrms. solid matter in solution 5).

The lakes of Gérardmer, in the département des Vosges, and Issarlés, in the département Ardéche, whose drainage areas are situated in granite, hold per litre of water 5.9 and 10 merms. carbonate of lime in solution; those of Chauvet, Godivelle-d’en-Haut and Pavin (in Puy-de Dome), situated in basalt, 6.8, 5 and 15.7 mgrms., whereas for the total of the solid matter in solution these lakes were found to keep 21.1, 27, 21, 18.3 and 79 mgrms. per litre of water °).

The Rachel-See, a little mountain lake, situated in the Bavarian Forest in cordierite-gneiss, and having an outlet, contains, according to the analysis of H. L. Jonnson’) only 2.22 mgrms. calcium carbonate per litre of water.

') Caleulated from the total of the solid matter in solution and in suspension yearly carried (1. ¢, p. 53) and the yearly discharge of water (l. e., p. 51). On its further course the Elbe has so much opportunity to dissolve different substances, especially carbonate of lime, that its water above Hamburg contains per litre 237 mgrmns. of total solids in solution (PENck, Morphologie der Erdoberfliche, Stuttgart 1894. I Theil, p. 309.)

*) According to 7 analyses by A. BELonousek (Untersuchungen des Moldauwassers) in Sitzungsberichte der K. Bohmischern Gesellschaft der Wissenschaften in Prag. 1876, p. 37.

*) Berichte des Deutschen chemischen Gesellschaft. 1887, p. 1786.

*) Archives etc. Gentve 1892, (3) T. 28 p. 504.

°) Ibid. p. 503.

*) Calculated from the results of analyses, published by Detesrcqur, Les laes fran- gais, p. 202—203. See also, Carte Géologique de France aw 1/g 999, feuilles Epinal, Le Puy et Brioude,

7) Livpie’s Annalen der Chemie, Bd, 95 (1855), p. 230,

(61)

The large lake Onega!), which is almost entirely surrounded by Finland granites and diorites, contains only 10.8 mgrms. calcium carbonate per litre of water.

The water of Lake Superior, whose drainage basin is composed of ancient sandstones, conglomerates and crystalline rocks, with very little limestone *), keeps only 30.8 mgrms. calcium carbonate, 45.7 mgrms. of total solids in solution per litre *).

Reindeer Lake, lying in the great archean area of Central Canada, north of Lake Winipeg, has only 29 mgrms. dissolved solid matter, of which only a slight trace of lime, in a litre of water *).

Lake Tahoe, amid the granitic and shistose peaks of the Sierra Nevada and ‘overflowing in the Truckee River, has 72.3 mgrms. of dissolved solid matter, of which 23.2 mgrms. are carbonate of lime, in a litre of water >).

Other lakes, which receive their water entirely or for the greater part, from areas of glacial deposits, which consists, mostly of the débris of crystalline silicate rocks, diluvial regions, are equally poor in calcium carbonate. So the lake of Starnberg or Wiirmsee in Bavaria °), which holds in solution only 4.8 mgrms. calcium carbonate per litre of water, and Loch Katrine in Scotland, which according to the analyses of WALLACE’), contains in a litre of water only 2.7 mgrms. CaO, for the greater part still bound to SO;, and of which the drainage area, according to the description of Sir Jonn Murray and F. P. Put- LAR ‘) consists almost entirely of drift (clay, sand and gravel), by the side of shistose grit with some mica-shists and very little diorite, rocks, which do not contain carbonate of lime. The latter is also wanting in the mud on the bottom of that little lake®). Lake Wener has only 36.2 mgrms. and lake Wetter 51.7 mgrms. matter in solution per litre of water!) In the drainage area of both these Swedish

') C. Scumipr, in Bulletin de Académie imp. des sciences. St. Pétersbourg. T, 28 (1888), p. 248.

*) R. D. Twine, The copper-bearing rocks of Lake Superior. Monographs of the Vj. S. Geological Survey. Vol. V. Washington 1883, p. 340.

*) Analysis in Geological on Natural History Survey of Minesota. Eleventh annual Report, p. 175, quoted by Warren Upham, The Glacial Lake Agassiz. Washington 1895. Monographs of the U. S. Geol. Survey. Vol. 25, p. 444.

‘) From analysis by F. W. Cuarke, quoted by I. C. Russet, History of Lake Lahontan, p. 42.

*) Geology and Natural History Survey of Canada. Report of Progress for 1880 — 1882, p. 6. H.

®) Menpivs, in Jahresber, der Chemie fiir 1856 p. 765.

7) Report of the meeting of the British Association for the Advancement of Science, held at Manchester 1861. London 1862, p. 94.

8) Geographical Magazine. Vol. 25. 1900. Plate II.

nt Te SPEE

*”) A, ALMEN in; Berichte d. Deutschen chemischen Gesellsch, Berlin 1871, p. 751.

( 62 )

lakes by the side of crystalline rocks only diluvial soil oceurs.

All the last named lakes are, in respect to their having an outlet and concerning their nearly constant composition, which is dependent on the chemical character of their drainage area, to be compared with the lake of Geneva and the other beforenamed lakes which are all rich in lime. Likewise the very large lake Baikal, through which flow the Upper Angara and the Selenga and which moreover receives some two hundred small rivers, and rivulets, and over- flows in the tumultuous Lower Angara. As far as that region has been geologically explored, there are found in the draining area of lake Baikal, besides of some pleistocence formations, principally archean rocks, also, however, to relatively small extent, palaeozoit limestone. Calculated according to the’ analyses of Scumipr !) its water (taken in April 1877 from under the ice) keeps per litre not more than 40.1 mgrms. carbonate of lime in solution. Lake Tschaldyr in Armenia, another, much smaller lake, of about 150 KM? surface and likewise having an outlet, containing only lixiviation water from trachytes, kept in solution (28 July 1879) per litre 42.5 mgrms. calcium carbonate. This relatively high figure for a basin situated in silicate rocks may be explained by the continual movement of the shallow water of the lake by violent gusts of wind, which keep it troubled and of a milky colour*). In consequence of this the suspended detritus of the rocks can more easily be decomposed by water and carbonic acid.

According to the estimate of TrLLo *), the crystalline silicate rocks occupy about '/, of the land surface of the earth, surely a much larger surface than that which is occupied by the limestone rocks. As nevertheless the river-waters take their carbonate of lime by far the greater part from the limestone mountains, it follows that the making of calcium carbonate from calcium silicate is a much slower process than the solving of previously formed limestone, and. that therefore the above calculated quantity of two billion KG. of calcium carbonate performs for much the greater part a real circulation, of which only very little is newly added carbonate, though all the calcium carbonate of the earth must gradually have originated from the decomposition of silicates.

1) C. Scumrpr in Bulletin de VAcadémie imp, de St. Pétersbourg, Tome 24 (1878), p- 420.

) ©. Scumrpr in Mémoires de Académie imp. de St. Pétersbourg (7). Tome 29. (1881), p. 46 and 48.

8) Comptes Rendus, Académie des Sciences, Paris 1892, p. 5.

( 63 )

Chemistry. — “The solubility of calcium carbonate in sea-water” By Dr. Ernst Conren and Mr. H. Raken (Communicated by Prof. H. W. Banus Roozrsoon).

Whilst engaged in forming a theory on the age of the earth, it was of importance to Professor Kuaine Dusois to possess further data as regards the solubility of calcium carbonate in sea-water under the usual conditions of temperature and pressure.

It is at his request that we undertook a research in order to obtain those data.

The modus operandi was, that sea-water in contact with the atmosphere (having the normal amount of carbon dioxide) was saturated with calcium carbonate and that after this point was reached, the amount of CaCO, dissolved in an aliquot part of the liquid was estimated by analytical means.

Arrangement of the Experiments.

We prepared some litres of sea-water accepting as its po aaants that found by Dirrmar }). He finds the total percentage of salts to be 3.5 consisting of:

NaCl = 77.758 MgCl, 10.878 MgSO, 4.737 CaSO, 3.600 K,SO4 2.465 MeBr, 0.217

100.000

The calcium carbonate was precipitated CaCO, previously tested for the absence of other carbonates. As the solubility is dependent on the temperature this had to be carefully regulated. The experi- ments were made at 15°, which temperature was kept constant within 0.03—0.05° for some montis. For this purpose we employed a thermostat with a toluene regulator also a spiral of composition tube through which streamed the water from the mains. This tube was placed in the water of the thermostat. The cooling thus caused

1) Report on the scientific results of the voyage of H. M. S. Challenger 1873~’76 1884, pag. 204. 2) The CaCO, was only added afterwards when determining the solubility,

( 64 )

was automatically compensated for by means of a gas flame con- nected with the regulator.

In the thermostat in which a few puddle- boards were kept in motion by a Henricr hot-air motor, were placed two bottles con- taining the sea-water with a large excess of CaCO;. The bottles were closed by trebly-perforated corks. Through the first hole passed a glass tube down to the bottom of the flasks, through the second one a glass tube ending immediately below the cork. Through the third hole passed a thermometer. A current of air was passed through the tubes reaching to the bottom of the flasks; this current was always strong enough to thoroughly stir up the aden car- bonate. The air entered the room through a glass tube which was pushed through an opening of the window ee passed through a meter in which its volume was measured and was then conducted through a spiral of composition tube 10 meter in length which was placed in the thermostat. In this manner it was heated to 15° before entering the sea-water.

The tubes which ended underneath the corks of the flasks were connected with a water-suction airpump which drew the current of air through the water.

A slight evaporation of the sea-water takes place which is but irifling as the air takes up water from the meter, but we have still taken notice of this and carefully marked the level of the liquids so as to be able to keep this regularly constant.

The time of saturation was varied in order to be sure that equi- librium had indeed set in. Therefore, an analysis was made after passing the air for 8 days and nights and another after the lapse of 17 days and nights; these gave the same results so that it may be taken for granted that 8 days and nights are already sufficient to reach a state of equilibrium.

From time to time the CO, of the air which had passed through was estimated. To do this, we interposed in the arrangement a large flask holding about 5 litres through which the air passed before reaching the meter. After 1—1'/, hour the CO, was estimated by shaking with standard barium hydroxide and titrating the excess with succinic acid. In calculating, due regard was paid to the tem- perature and pressure.

When the experiment was finished, the current of air was stopped and the CaCO; was allowed to deposit. Then the liquid was filtered at 15°,

( 657) Analyse.

Under the circumstances described, there existed in the water ') after the experiment :

1. Carbon dioxide in the free state.

2. Neutral calcium carbonate.

3. Acid calcium carbonate.

Through the clear solution was now conducted a current of air which was completely freed from CO, by passing it through a 2 meter long tube filled with soda-lime and some washbottles containing aqueous caustic potash. On passing a neutral gas such as air, both the free carbonic acid and that of the acid calcium carbonate are expelled whilst neutral calcium carbonate is precipitated.

Specially conducted experiments, one of which lasted 4'/, and the other 100 hours, proved that after 41/2 hours the decomposition of the acid calcium carbonate and the expulsion of the carbon dioxide is complete.

The solution thus treated was now examined as to its amount of combined carbon dioxide (CaCO;) by decomposing this with hydro- chlorie acid and weighing the expelled CO, in soda-lime tubes, according to the method of Konps-FResENrIUS 7) which was carefully followed in every particular. i

Results.

300 ce. of sea-water were used for each analysis.

a. Solution of Ca CO; through which was first passed a current of atmospheric air for 8 days and nights and then a current of air free from CO, and saturated with water vapour, for 4'/. hours.

According to the indication of the meter, 41100 litres of air had passed through the solution in 8 days and nights which is about 108 litres per hour.

Three estimations of carbon dioxide made during this time on different days gave as result 0,0371, 0,0323 and 0,0290 per cent of CO, by volume.

_ Found 16,2 milligrs of CO, in 300 ce. of solution saturated at 15°, or 53.94 milligrs per litre.

b. Solution of Ca CO; through which was first passed a current of atmospheric air for 17 days and nights and then a current of air free from CO, and saturated with watervapour for 100 hours.

Found 17.2 milligrs in 300 ce. or 57.27 milligrs per litre. We, therefore, find that. sea-water saturated at 15° with calcium carbonate

') Compare GueLin-Kravr, Handbuch Anorg. Chemie, Part 1, 358.

*) Fresenius, Anleitung zur quant. Chem. Analyse, Bd. I (1875) § 449. 5

Proceedings Royal Acad. Amsterdam, Vol. II,

( 66 )

contains an amount of 55.6 milligrs of neutral-combined COg per litre. It now appears from the researches of JACOBSEN !), TORN¢E *) and Dirrmar®) (CHALLENGER Expedition) that the amount of neutral combined GO. in sea-water varies from 52.8—55 milligrs. per litre. Our research, therefore, leads to the result that sea-water is satu- rated with calcium carbonate. Amsterdam, Chemical University Laboratory, March 1900.

Physics. — “On the phenomena of condensation in mixtures in the neighbourhood of the critical state”. By Dr. Cu. M. A. HARTMAN (Communication N°. 56 from the Physical Laboratory at Leiden by Prof. H. KAMERLINGH ONNES).

In a communication of DunEm*) the hypothesis is laid down that in a mixture of two entirely miscible substances the experimental and the theoretical isothermals for one and the same temperature, situated between the temperature of the plaitpoint and that of the eritical point of contact, intersect twice in the area of the unstable conditions.

On p. 31 and in thesis I of my disserta- tion for the doctorate *) I have drawn attention to the fact that this hy- pothesis is at variance with VAN DER WAALS’ ..» theory of mixtures ®). = The following may serve as a nearer ex- planation.

The actual condition may be seen from the annexed figure, derived from my dissertation in which the lines of equal pressure on the a-sur- face in the neighbour-

') Liesie’s Ann. 167. 8. 1 (1878); Jahresbericht der Commission zur wissenschaft- lichen Untersuchung der deutschen Meere in Kiel. 1872, 8. 43,

*) Den Norske Nordhays-Expedition 1876-78.

4) lee.

') Procés-Verbaux des séances de la Soc. des Se. phys. et nat. de Bordeaux, 1899.

5) Metingen omtrent de dwarsplooi op het -vlak van VAN ber WAALS bij mengsels van Chloormethyl en Koolzuur. Leiden, Juni 1899.

5) vAN pur Waats, Arch, Néerl. XXIV, p. 1—56, 1889.

(68)

hood of the area of the retrograde condensation are drawn projected upon the «V-plane.

That the course of the lines of pressure must be so, follows from VAN DER WaAALs’ formula, concerning all points of the connodal line in the w-surface:

oy d’y ow \2 fk eM (OU by GP 2 5 2? (ra) fizz 2 ale taal ey ')

ave

as has been explained on p. 30 of the dissertation.

As the second member of this equation is always positive (at the 2

: ; dP : plaitpoint P it becomes zero, at the same time as eae) the two factors av of the first member have always the same sign. ie ; METS ean nate In the critical point of contact 2, where —— is infinitely great, ar ' the tangent-chord will touch the projection of the line of pressure. g pro) I Therefore in each point between P and F, where, as follows from

dP . i se ae

the figure, —— is negative, =) wili be greater than —_——.,, or dz On p 2—z

in words: there the line of pressure will be steeper with regard to

the z-axis than the chord.

At the other end of the chord, where — ;

dP . -—

18 positive, the slope of the line of pressure will be less steep,

For pressures between Pp and Pr the lines of pressure in the unstable part lie therefore in projection between the chord and the connodal line, so that the projections of the chord and the pressure line for one and the same pressure between Pand R cannot intersect.

For pressures lower then Pr the chord and the line of pressure will intersect in projection only in one point S. The line in which these points of intersection are situated extends over the whole breadth of the plait and terminates in the critical point of contact R.

If now we follow a line x=, with decreasing volume, we shall

‘) van per Waats, l.c. p. 15; in this formula a difference has been made between P the two-phase-pressure, and p the pressure in any point of the y-surface. 7, 2 and F', x' then refer to the co-existing phases,

2) VAN DER Waals, l.c. p. 56.

( 68 )

be able to deduce the phenomena of condensation from the figure.

In the beginning of the condensation we shall for one and the same pressure first meet the line of pressure at a, then the chord at 6, beyond S on the contrary, we first meet the chord at ¢ and then the line of pressure at d.

If now we map the connection between V and p on a Vp-dia- gram, we shall refind the above-mentioned point of intersection for all mixtures, which show condensation, as the intersection of the experimental and theoretical isothermals, and this will be their only intersection. In the same way at the beginning of the condensation the first-mentioned isotherm will always be situated below and afterwards beyond the point of intersection always above the second.

2. Dunem has arrived at his hypothesis in the following way :

First he traces how the total volume 1 of a complex of two phases varies with the two-phase-pressure P, if the temperature remains constant.

Let x, VY and m be the composition, molecular volume and quantity of the first phase (liquid), 2’, V' and 1—m those of the second phase (vapour), and 2, the mean composition of the complex, then is

i) =n) 3 ©, Sve. (CEE

}

dm

+l gee

Now Dwunem considers what this relation becomes at the plait- point. Then

cram rats G=G)m GQ).

Te Le" Moreover he assumes, that here also —— = —— and so concludes dP dP hat (25). (SE) ana (2) ly great at the plaitpoi Ab = , = € md are ‘ y oreat at t Alb ¥ tha es 1 >), ap sift equally great at the plaitpoint.

dx He overlooks however that at the plaitpoint ae is infinitely great j ,

so that these quantities are not equal.

( 69 )

In the plaitpoint therefore the experimental and theoretical iso- thermals in the Vp-diagram have not the same tangent, as has been wrongly drawn by Dunem. Hence his further conclusions may be neglected.

3. Prof. VAN DER WAALS was so kind as to inform me that the mutual relation of the theoretical and experimental isotherms, and hence also the error of DuHEM’s theorem, can be directly de- duced from the sections of the w-surface and of the loeus of the tangents-chords by a plane x = const.

Fig, 2a. Fig. 20.

For this Prof. van DER WAALs remarks: 1%. that — see fig. 2¢ and 2°1) where w has been taken as ordinate and V as abscissa — for a definite mixture the experimental y-line ASD must lie below the theoretical line AS'D.

2nd. that at the beginning and end of the condensation, at A and D, the experimental and theoretical y-lines have the same slope, and touch at those points.

3°¢. that hence for a volume B in the beginning of the conden- sation the theoretical w-line has a greater slope than the experi- mental, or Per.< ptheor. An equality of pressure for one and the same volume will again be attained where the tangents to the two w-lines become parallel, at S and S’ in the figures. Again for a volume C near the end of the condensation the experimental w-line has a greater slope than the theoretical, or Pezp. > Ptheor.

1) Fig, 2a relates to the case where the critical temperature of the mixture, sup- posed to remain of constant composition, lies below, and fig. 24 where it lies above the temperature, for which the -surface is constructed; or: fig. 2a refers to yalues of x on one side, fig. 24 on other side of the straight line parallel to the V-axis and passing through X, the theoretical critical point on the p-surface, see Dissertation Pl. I fig. 5. K does not necessarily coincide with the intersection of tangent-chord and line of pressure.

( 70 )

The points S and S’ agree with the intersection of the two iso- thermals in the Vp-diagram, fig. 3¢ and 34, and with the inter-

f at Sg

“

=v

~ | v

<—

Fig. 3a. Fig. 30.

section of the chord and the line of pressure in fig. 1. As no other eases than fig. 2¢ and 2° are possible there is only one such point.

4. With respect to the course of the condensation in the case of mixtures the following remarks may be added.

In the Vp-diagram the experimental isothermal can be either convex or concave towards the V-axis. The first is the case for a mixture which contains only a small proportion of the more volatile component, as occurs in VERSCHAFFELT’s experiments ') — see fig. 3¢ —. The second is the case for mixtures which consist prin- cipally of the more volatile substance, as occurs in KUENEN’s expe- riments*) — see fig. 3° —.

The experimental y-line will have its greatest curvature near D in the first case, near A in the second (comp. fig. 27% with fig. 3¢ and fig. 2 with fig. 3°).

Physics. — ‘“Weasurements on the magnetic rotation of the plane of polarisation in liquefied gases under atmospheric pressure’. I. By Dr. L. H. Srertsema (Communication N°. 57 from the Phys. Labor. of Leiden by Prof. H. KaMERLINGH ONNES).

1. The continuity of the optical properties of substances under dif- ferent circumstances of pressure and temperature, especially during changes in the state of aggregation is an important point of invest- igation on which light can be thrown by measurements of the mag- netic rotation of the plane of polarisation. If we calculate from the

») Versl. Kon. Akad, v. Wetensch. Amsterdam 24 Dec. 1898, p. 281; Proc. id. I, p. 288 and 323; Comm. Phys. Lab. Leiden, N°. 45.

2) Proc. R. Soe. Edinb. 21, p. 483, April 1897. Zeitschr. f. phys. Chem. 24. pag. 672, 1897.

-

n®(n°— 1)

CP)

observations the molecular rotatory constant @p,'), this quantity will generally depend on pressure and temperature, and we can consider the manner in which it changes during the transition from the gaseous to the liquid state.

Measurements on this subject have been made by Brcqueret and by Bicuat*) with Carbon disulphide and Sulphur dioxide as liquid and vapour. From these observations, in which no determinations of dispersion have been made, it follows that during the transition into the gaseous state the magnetic rotation of Carbon disulphide decreases much more rapidly than the density; and that Becqueren’s formula ua = Const. holds during the change of the state of aggregation.

My measurements on the magnetic rotation in gases °) led me into an investigation in this direction, which also was furthered by the ample means offered by the Leiden laboratory for experiments with liquid gases.

2. For the measurements of the magnetic rotation in liquefied gases under atmospheric pressure some special difficulties have to be surmounted. In the first place care must be taken that the cylinder containmg the liquid, which must let through the pencil of light, shall be free from bubbles of gas which may easily be generated on the walls when they are not properly protected against the en- trance of heat by conduction. Moreover this cylinder should be closed by plane parallel plates of glass of very good quality, as for these measurements it is difficult to place the nicols 7 the experimental-tube and thus within the closing-plates as could occur in the measure- ments on gases. These plates must also be protected against the entrance of heat but especially against moisture, as the least for- mation of ice on these plates hinders the measurements. This renders it necessary to place more than one set of glass-plates between the nicols, which latter circumstance again makes it necessary to use greater rotations than was required for the investigation with gases, as the glass-plates, good as they may be, render the adjustments less accurate.

8. The difficulties mentioned have been taken into account in

1) Comp. Proc. Royal Acad. Amsterdam. Vol. I, p. 299. BecqvereE., J. de Ph. (I) 8; p. 198. Bicnar. J. de Ph. (1) 8 p. 204; 9 p, 275. (t) 8, p I

%) Proc. Royal Acad. Amsterdam. Vol. I, p. 296. Arch. Néerl. (2) 2 p.291. Comm. Phys. Lab. Leiden, Suppl. 1.

( 72 )

constructing the apparatus shown in figs 1 to 3, which consists of glass and ebonite only.

The experimental tube which is filled with the liquefied gas, consists of a glass tube a, closed by the glass-plates b, fastened to the tube by means of fishglue. By means of some brass collars ¢, acting as springs, a loose glass tube d lies in the experimental tube of the same length as the latter. The spaces within and round the tube are connected by means of the two obliquely ground ends at EH. Through this tube d the pencil is directed during the measurements. The experimental tube is filled with the liquefied gas to a little above this loose tube, which thereby is filled with the liquid and entirely surrounded by it. Even supposing that a few bubbles of vapour arise on the walls of the experimental tube, they cannot get into the liquid contained in the loose tube and will not disturb our field of view.

The experimental tube is moreover surrounded by two glass tubes f and g. Through the openings 4 and 7 the cold vapour of the liquid in the ex perimental tube can stream successively through the two spaces formed by these glasses, and then escape through the india-rubber tube &, fastened to an ebonite ring / round the last named tube. The tube / conducts the vapour to a caoutchouc bag, in which it is collected provisionally, to be afterwards condensed. The liquid is admitted through an opening in the ebonite nuts m, which also serve to connect the various glass tubes.

To fill the tube we use the steel capillary @ (fig. 3) which is put through the opening in the nuts m (fig. 1) so as to reach into the experimental tube, to which it is fastened by means of the cap 6 (fig. 2). When the tube is filled we remove this capillary and close the opening by means of a small stopper.

The two glass tubes f and g are closed by the ebonite caps 2, in which caoutchouc rings o serve as washers. The caps are mutually connected by six brass tightening rods. The closing plates 6 of the experimental tube are kept in their places by means of the ebonite rings p in the caps ». These closing plates are shut off from the atmosphere by means of the glass-plates g, enclosed by the nuts 7 together with a leather packing s. These latter glasses are again protected against the formation of ice by spaces formed by them and the plates t, which spaces can be filled with dry air by means of the ebonite tubes u, or by placing some Phosphorous pentoxide into them!). The spaces between the glass-plates 4 and q

1) Comp. the Cryostate, Proc. Roy. Acad. Amsterdam, Sept. 1899.

Ji) : ’

ma . sie - ee be ph) oil

a eh de lies) yy pel

VN OV Oe uv vi "4 lee j PTO Cy bald» Wt SPOT) he fe vn 4 ith en ‘ Hae aii : j !

0 Hipitiiieg me Dio win) Lad uirtity ae ‘ y Bisa finn. bail! Mi ‘eyo at PL ke at Ue inet al Se ee

Hel Wyl p a)! nor oevel” gh zu bed Se ee r .

ie

i } ivi Hii HO } P ayy we wt " Fri uet 2 fp BOR) Maou i a nn a A Sari ee ein E ma mw = ae ‘ : “4 Ad Fines Ale } et iol * AhAa halge 4) ibd Ai 1 Ay vl igh ee te Li. may : ea ” iD hee ¥ 7 [a 7 Y itirte cat i ai oft; fit MSY WT 7 - ee te ii. fee yrcin a ‘ A u i? r 7 d sui “oe avi st Dated voy wo “1 mii a > fi rr Ly ei ne a rn! + = Le A mae ih AU > , ri = ed iis cia, wlth vey Dain ’ Nei, ri ringer rringet — — es Pi \ ; { a : 7 i aA a e AS 4 =

OO Oe MiGente e mT Dy * Saal" js oo, | :

eee. fij jak ir

wiles We rt ALdt Gags! Jie dennd ris NO dai ooi PALIT ful roar) yinlit i tad ayen Ee DAM oot.

'

ig ale ony piel Sant. pe Meph'e OO a ty i ul

ae ny Pe Avs aapaliemurty Ba? te wn | é [Aan

ae sy Bist vu coll D jie Sarto sinitisott Ao eiie adregoy % Atv , ui? Wis Fe id on de Oia) felin WIGEs: Fulah H ful? | ot r oom a i SY ie jny THR nisl ye esta, od? Die une

bei Ra pioaley: rr Ne ee keiela, ». wid) if efueyii 2

fit yey Pp

i aig Honea wiate BAT: (CL i ig) dhitkotiney

ae f _ Eteltoih tg y PY as inn? sible ilies) aoe) 4 -

ie ‘

oat

C1)

In this table w/@p stands for the proportion of the rotation to that for sodium light.

A (w/wp) CH, Cl (a/wp) gases

0.631 0.90 0.87 0.546 1.17 1.17 0.480 1 58 1.53 0.449 1.76 1.76 0.435 1.90 1.90 Chemistry. — “A new method for the exact determination of the

Boiling-point”?. By Dr. A. Sirs (Communicated by Prof. H. W. Bakuurs Roozesoom).

(Will be published in the Proceedings of the next meeting). Chemistry. — “ Thermodynamics of Standard Cells” (2"¢ part). By

Dr. Ernst Coen (Communicated by Prof. H. W. Baknurs ROOZEBOOM).

(Will be published in the Proceedings of the next meeting). Chemistry. — “On the Enantiotropy of Tin” (VN). By Dr. Ernst Conen (Communicated by Prof. H. W. Baknurs RoozeBoom).

(Will be published in the Proceedings of the next meeting.) Chemistry. — ‘The formation of mixture-crystals of Thalliwm-

nitrate and Thalliumiodide”, By Dr. C. vAN Eyk (Commu- nicated by Prof. H. W. Bakuurts Roozesoom).

(Will be published in the Proceedings of the next meeting.)

(June 30, 1900.)

KONINKLIJKE AKADEMIE VAN WETENSCHAPPEN TE AMSTERDAM,

PROCEEDINGS OF THE MEETING

of Saturday June 30, 1900.

———26G

(Translated from: Verslag van de gewone vergadering der Wis- en Natuurkundige Afdeeling van Zaterdag 30 Juni 1900 DI. IX).