May io, 1900] 



NA rURE 



47 



three groups according to their inclination, the mean distance 

 of the planets of these groups from the sun is sensibly constant. 

 — ^On the transparency of aluminium for the radium radiation, by 

 M. Henri Becquerel. A study of the penetration of thin alu- 

 minium sheet by the radium rays, the latter being placed in a 

 strong magnetic field and the effects of the deviable and non- 

 deviable rays being studied separately. — Study of manganous 

 fluoride, by MM. Henri Moissan and Venturi. Pure anhydrous 

 manganous fluoride, MnFa, was obtained in four ways : by the 

 action of a solution of hydrofluoric acid upon metallic manganese, 

 by the interaction of gaseous hydrogen fluoride and the metal, by 

 heating manganese fluosilicate in a current of 11 F at 1000°, 

 and by dissolving manganese carbonate in the acid. The 

 crystallised MnFo could not be prepared from aqueous solution, 

 on account of the sparing solubility of the salt in water, but is 

 readily obtainable by fusing a mixture of the salt with manganese 

 chloride. — Agricultural maps of the Canton of Redon. The 

 composition of the soil from the point of view of lime, mag- 

 nesia, potash and nitrogen, by M. G. Lechartier. An account 

 of the work carried out at the agricultural station of Rennes. — 

 On the vertical trunks, stems and roots of Cordaites, by M. 

 Grand 'Eury. The view is put forward that Cordaites, like 

 Sigtllaria and other fossil plants dealt with in previous papers, 

 actually grew in the place where they are found, many ligneous 

 trees commonly regarded as growing only on dry land flourish- 

 ing well with their lower portions constantly submerged in 

 water. — Prof. Suess was nominated a Foreign Associate in the 

 place of the late Sir Edward Frankland. — On a relation between 

 the theory of continuous groups and the differential equations 

 with fixed critical points, by M. Paul Painleve.— On the 

 function S introduced by M. Appell into the equa- 

 tions of dynamics, by M. A. de Saint Germain. — An im 

 proved and simplified solar microscope, by M. A.Deschamps. — 

 The telemicroscope, by M. A. Deschamps. — On an experiment 

 of M. Jaumann, by M. P. Villard. In an experiment described 

 by M. Jaumann, a charged glass rod was bi-ought near a tube 

 immersed in oil, in which kathode rays were being developed, 

 the bundle being repulsed. As these results were not in agree- 

 ment with the usual hypotheses concerning the kathode, an at- 

 tempt was made to repeat the experiments, but no deviation of 

 the rays in the opposite direction to that predicted by the theory 

 could be obtained.— On the radium radiation, by M. P. Villard. 

 The rays not deviable in a magnetic field have much greater 

 penetrative power than the deviable rays. The ordinary X-rays 

 from a Crookes' tube behave similarly. — Luminescence of rare- 

 fied gases round a metallic wire communicating with one of the 

 poles of an induction coil, by M. J. Borgman. — On the 

 hysteresis and viscosity of dielectrics, by M. F. Beaulard. 

 From the results of the experiments given, the author 

 concludes that dielectrics do not present the phenomenon 

 of hysteresis, but are only endowed with viscosity. — On 

 samarium, by M. Eug. Demar^ay. The properties of the 

 samarium isolated by the method of double magnesium 

 nitrates previously described are so well defined that it would 

 appear to be a simple substance analogous to other elements 

 and not a mixture. The pale yellow colour of the oxide is 

 apparently not due to any impurity. The atomic weight, as 

 determined by the sulphate method, is about 147 "5. — On the 

 combination of sulphur dioxide with metallic iodides, by M. E. 

 Pechard. Potassium iodide, either in solution or in the solid 

 state, rapidly absorbs sulphur dioxide, the compound KI.SO2 

 being formed. This compound is easily dissociated into its 

 constituents, its dissociation pressure at 0° being 60 cm. of 

 mercury, at 30°, 238 cm. Other iodides form similar com- 

 pounds. — On the gases emitted by the Mont Dore springs, by 

 MM. F. Parmentier and A. Hurion. The gas is carbon dioxide 

 containing 0*49 per cent, of nitrogen and 'oi per cent, of argon. 

 — Bromination with aluminium bromide, by M. Ch. Pouret. 

 Organic chlorinated compounds, heated to their boiling 

 points for some time with aluminium bromide, give 

 good yields of the corresponding bromine derivatives. The 

 preparation of bromoform, methylene bromide, methyl bromide, 

 ethyl bromide, pentabromethane, ethylene, ethylidene and acetyl- 

 ne bromides is described in detail. — The action of monochlor- 

 > etic esters upon the sodium derivative of acetylacetone, by M. 

 i . March. The compounds (CH8.CO)2.CH.CH2.CO.OCjH5 

 nd (CHj.CO)2.CH.CH2.CO.OCH8 are described; and also 

 lie products of the reaction between these bodies and phenyl- 

 iiydrazine. — Action of ethylidene chloride upon phenols in 

 presence of potash, by MM. R. P'osseand J. Ettlinger.— On the 



presence of tyrosine in the water of contaminated wells, by M. 

 H. Causse. The water from contaminated wells at Lyons gave 

 an orange coloration with the chloromercurate of sodium para- 

 diazobenzenesulphonate which proved not to be due to cystine. 

 Tyrosine was then extracted and identified by analysis. — On 

 some changes which occur in plants grown in the dark, by M. 

 G. Andre. A set of comparative analyses of maize and lupin 

 plants grown in sunlight and in the dark. — Studies in develop- 

 ment oi Petromyzon Planeri, by M. E. Bataillon. — Modifications 

 in structure observed in cells undergoing a true fermentation, by 

 MM. L.Matruchot and M. Molliard. The fermentation of the fruit 

 of Ctiatrbtta maxima was carried out under conditions excluding 

 the possibility of intervention of any foreign organisms. Every 

 cell in a state of true fermentation shows a very clear nucleus, 

 a small amount of chromatine arranged on the periphery of the 

 nucleus, a protoplasm full of vacuoles, and numerous minute 

 drops of essential oil formed in the protoplasm. — Botanical 

 zones in French Western Africa, by M. A. Chevalier. — On the 

 granites and syenites of Madagascar, by M. A. Lacroix. — On 

 the Gothlandian of the Peninsula of Crozon (Finisterre), by 

 M. F. Kerforne. — Influence of temperature on the fatigue of the 

 motor nerves of the frog, by M. J. Carvallo. Temperature has 

 a considerable influence upon the activity of motor nerves, the 

 excitability increasing up to 20° C. — The functions of the crystal- 

 line tube of the Acephala, by M. Henri Coupin. The function 

 of this tube appears to be digestive, a storehouse of diastases.— 

 Topography of the mouth as regards sensitiveness of taste, by 

 MM. Ed. Toulouse and N. Vaschide. 



Amsterdam. 

 Royal Academy of Sciences, March 31. — Prof. H. G. 

 van de Sande Bakhuyzen in the chair. — On orthogonal comitants, 

 by Prof. Jan de Vries. — On indigo fermentation, by Prof. Beyer- 

 inck. Indigo fermentation is the decomposition of the giucoside 

 indican into indoxyl and glucose by the action of a cell. This 

 is eff^ected in two ways : first, by katabolism, i.e. by the direct 

 action of the living protoplasm on the indican ; secondly, by 

 specific enzymes. All the indican splitting bacteria examined 

 act by katabolism, and are quite inactive when dead. The 

 indican plants and some kinds of yeast contain indigo enzymes, 

 and so are still active when dead. The indigo enzymes of 

 Indigo leptostachya. Polygonum tinctorium, Phajtis grandijlorus, 

 Saccharomyces sphaericus, and the emulsion of sweet almonds, 

 which also acts feebly on indican, proved to be quite different 

 enzymes with optima of activity at 61°, 42°, 53°, 44° and 55° C. 

 respectively. The action of all of them is increased by acid to the 

 amount of 0*5 c.c. normal per 100 c.c. of indican solution ; more 

 acid as well as alkali decrease their activity. In indigofera 

 there is no katabolism, whilst in Polygonum there is a slight 

 katabolism at low, in Phajus a very strong katabolism at high, 

 temperatures. Hence the last two decompose indican in both 

 ways at once, while indigofera does so by enzyme action only. 

 In the leaves of Phajus indican is localised in the protoplasm 

 both of the cells of the epidermis and of the mesophyll ; the 

 indigo enzyme occurs in the chlorophyll granules. — Prof. 

 Hoogewerfi^ presented on behalf of Mr. J. Hazewinkel, manager 

 of the "experimenting station "for indigo at Klaten (Java), a 

 paper, entitled " Indican, its spUtting up, and the enzyme 

 which brings this about." This paper contains the results of 

 inquiries, made in 1898, which for technical reasons were not 

 intended for publication. Beyerinck's publication makes further 

 withholding useless. Mr. Hazewinkel observed that when all 

 enzyme actions are excluded, an aqueous solution might be 

 obtained from leaves of Indigofera leptostachya, which solution 

 by the action of enzymes and subsequent oxidation yielded 

 indigo. The glucoside-indican found in this solution appeared 

 to be a fairly stable substance (also at boiling heat and when 

 acted upon by alkalis), provided it was not exposed to the action 

 of enzymes (indimulsin, emulsin) and of acids. Mr. Hazewinkel 

 proved in various ways, among others by the formation of indi- 

 zubine (with isatin), that the indigo-forming splitting-product of 

 indican is indoxyl, and inquired into various circumstances in- 

 fluencing the detection of indoxyl in those solutions and the 

 formation of indigo from indoxyl, and also observed that 

 during the so-called fermentation of indigo leaves, no 

 indican, but indoxyl is present in the fermentation fluid. — 

 Prof. Hoogewerff' also made a communication on behalf of 

 Mr. H. ter Meulen and himself, entitled "A Contribution to 

 the Knowledge of Indican." Basing their inquiries upon the 

 above-mentioned inquiries by Mr. Hazewinkel and those made 



NO. 1593. VOL. 62] 



