240 



NATURE 



[January 7, 1892 



the lens containing a liquid is placed between a collimator and 

 an observing telescope, furnishes the datum from which the 

 index of refraction of the liquid can be calculated. The deter- 

 minations that have been made indicate that the method is 

 susceptible of high accuracy. — Researches on the application of 

 measurements of rotatory power to the determination of com- 

 binations formed by sorbite in aqueous solution with acid sodium 

 and ammonium molybdates, by M. D. Gernez. — Metallic 

 borates, by M. H. Le Chatelier. The author has prepared, 

 purified, and analyzed borates of magnesium, calcium, and zinc. 

 He concludes that many of the complex borates previously 

 described are in reality mixtures of comparatively simple 

 borates with boric anhydride, and that the only types of borates 

 of which the composition is sufficiently established are • 

 B2O3, 3MO; B2O3, 2MO; B2O3, rsMO; and B2O3, MO.' 

 — On isomeric chromic sulphates, by M. A. Recoura. — 

 On a silicon chlorosulphide, by M. A. Besson. The 

 compound SiaClgSg has been obtained as a white solid, 

 crystallizing in long needles melting at 74°, readily de- 

 composing in the air, and acted on with violence by water. — 

 A new crystallized copper phosphide, by M. Granger. — The 

 solution of antimony chloride in saturated solutions of sodium 

 chloride, by M. H. Causse. — On a double cyanide of copper 

 and ammonium, by M. E. Fleurent.— Study of the thermal 

 properties of bibasic organic acids : influence of the alcoholic 

 function, by M. G. Massol.— Disodium glycol, by M. de 

 Forcrand.— Action of dilute nitric acid on nononaphthene, by 

 M. KonovalofF. — The formation of acetylene from bromoform, 

 by M. P. Cazeneuve. — Action of phosphorus pentachloride on 

 methylnaphthyl ketones : a and /8 naphthylacetylenes, by M. 

 J. A. Leroy. — Observations on the subject of a note of MM. 

 Arm. Gautier and R. Drouin, by MM. Th. Schlcesing, fib, 

 and Em. Laurent. — On the formation of cordierite in the sedi- 

 mentary rocks fused by the coal fires at Commentry (Allier), by 

 M. A. Lacroix. An examination of some rock specimens from 

 Commentry, where the underground combustion of coal has 

 been going on for some time, shows that the most abundant 

 mineral constituting the lavas formed (especially tbe ropy varie- 

 ties) is cordierite. This mineral occurs in small crystals, which have 

 not, however, been isolated and analyzed. It is accompanied by 

 octahedric spinellidsin connection with anorthite, and small, almost 

 rectangular, microlites. The augite often exhibits the chrondritic 

 structure of meteorites. The variation m the relative abundance of 

 cordierite, anorthite, and augite, their very unequal dimensions 

 in different specimens, and the relative abundance or rarity of 

 the glass, give rise to numerous interesting petrographical varie- 

 ties. Mallard's rhabdite has been easily recognized. The facts 

 show that cordierite is easily formed by the action of heat on 

 sedimentary rocks ; indeed, it appears from the observations to 

 be an habitual product of Carboniferous rocks modified by heat. — 

 Functionsof the pectiniform organ of scorpions, by MM. Charles 

 Brongniart and Gaubert. — On the regime of the oceanic sardine 

 in 1890, by M. Georges Pouchet. — On the presence of Httero- 

 dera .Schachtii in cultures of carnations at Nice, by M. Joannes 

 Chatin. — On a phtiriasis of fibrous copper, caused, in an infant 

 of five months, by Phtirins ingninalis, by M. Trouessart. — Ob- 

 servations on the cellulosic membrane, by M. L. Mangin. — On 

 the penetration of the violet filaments of the Rhizoctone fungus 

 in the roots of beetroot and lucern-grass, by M. Ed. Prillieux. — ■ 

 On the assimilation of parasitic plants by chlorophyll, by M. 

 Gaston Bonnier. — Earthquake of October 28, 1891, in Central 

 Japan, by M. Wada. 



Berlin. 

 Physiological Society, December 11, 1891.— Prof, du Bois 

 Reymond, President, in the chair. — Prof. Fritsch gave an 

 account, illustrated by specimens and preparations, of the general 

 result of his investigations on feebly electrical fishes, as far as 

 these dealt with the structural arrangement of the electric organ, 

 the nerves to the same, and the nerve centres. — Dr. C. Benda 

 spoke about his recent researches on spermatogenesis, entering 

 fully into the part played by the archoplasm in the development 

 of spermatozoa. 



Physical Society, December 18, 1891.— Prof. Kundt, Pre- 

 sident, in the chair. — Prof. Schwalbe recalled to the Society the 

 loss it had sustained in the death of Dr. Ewald, one of its 

 earliest and formerly most active members. — Dr. Budde gave 

 a resume of the work which has been done during the last ten 

 years on supersaturated solutions, and an account of the present 

 state of the question. — Dr. Paschen spoke on gravitational 



NO. I I 58, VOL. 45] 



attraction and its measurement by Cavendish and his successors, 

 dealing specially with the work of Boys, whose methods he 

 explamed and whose apparatus he exhibited to the Society. 



Amsterdam. 

 Royal Academy of Sciences, December 19, 1891.— Prof, 

 van de Sande Bakhuyzen in the chair.— Dr. Bakhuis Rooze- 

 boom treated of the influence of isomorphism on the behaviour 

 of double salts during solution. He studied the isotherm of 

 15° for the saturated solutions possible with the system FeCI.,, 

 NH4CI, and HjO. When representing the numbers of mol. 

 FeC)3 and NH4CI pro 100 mol. HoO in the solution, this 

 isotherm consists of three branches. The first gives the solu- 

 tions in equilibrum with solid FeClj.eHoO, the second with the 

 double salt FeCI3.2NH4Cl.H2O, the thi'rd with mixed crystals 

 containing from ± 8 per cent. FeClj to zero. The three 

 branches have two points of sharp intersection. In the first 

 coexist the double salt with FeClg.eHoO, in the second the 

 double salt with mixed crystals containing the highest possible 

 percentage of FeCh,. These results confirm the rule that with 

 systems of three bodies the composition of a solution is variable 

 when only one solid phase lies at the bottom, but determined 

 when there are two solid phases. The occurrence of mixed 

 crystals besides double salts modifies the behaviour of the solu- 

 tion when one or other of the composing salts is added con- 

 tinuously. — Mr. J. A. C. Oudemans spoke on levels. He had 

 had to try two levels of an altazimuth of the Sumatra triangula- 

 tion, having each an air chamber at one of their ends ; using a 

 bubble not longer than one-third of the scale, he found the value 

 of a division in the first and last third two or three times larger 

 than in the middle, so that he inclined to reject the levels. But 

 trying the same levels with long bubbles — for instance, of two- 

 thirds of the scale — they proved much better, the inclination 

 given by the level-trier being nearly proportional to the 

 indication of the level, and the remainder of the irregularity 

 being easily taken into account by a table. The necessity 

 of making up, by experiment, a table of the inclination in a 

 function of the level-reading, being once admitted, the judg- 

 ment about a level ought to depend, not so much on the uni- 

 formity of the curvature, as on the constancy (the bubble 

 remaining of the same length) of the reading, the inclination 

 being the same ; which property may easily be tested by the 

 level-trier. 



CONTENTS. PAGE 



Indian Meteorology. By H. F. B .217 



French Malacology. By (BV)- 219 



Man's Place in Nature. By C. R 220 



Our Book Shelf:— 



Merrill :" Stones for Building and Decoration " . . . 222 



Acloque : " Les Champignons " 222 



Maxwell: *' Theory of Heat " 222 



Letters to the Editor: — 



The Implications of Science. — Dr. St. George 



Mivart, F.R.S. ; Miss E. E. C. Jones .... 222 



Supernumerary Rainbows observed in the Orkneys. — 



Kobert H. Scott, F.R.S. ; M. Spence . . 223 



Aurora Borealis. — J. Lovel ... .... 223 



A Double Moon. — Rose Mary Crawshay . . 224 

 On the Relation of Natural Science to Art. II. By 



Prof. E. du Bois-Reymond, F.R.S 224 



Chronophotography, or Photography as applied to 



Moving Objects. (Illustrated.) By W 228 



Sir George BiddellAiry 232 



Notes 233 



Our Astronomical Column : — 



Wolf's Periodic Comet 237 



The Diffraction Effects produced by placing Screens 



in front of Object-Glasses. . . ....... 237 



Refractive Power of Cometary Matter 237 



Himmcl tind Erde 237 



"Washington Observations, 18S6 " 237 



Molecular Weight of Gadolinia. By G. T. P. . . . 237 



Societies and Academies 238 



