26o 



NATURE 



\ymu 28, 1875 



Physical Society, Jan. 16.— Prof. Gladstone, F.R.S., in 

 the chair.— A paper was read on the electrolysis of certain 

 metallic cUorides, by the President and Mr. Alfred Tribe. If 

 metallic copper^ be immersed in solution of cupric chloride, 

 insoluble cuprous chloride is formed upon it. The authors found 

 that if a strip of platinum be connected with one of copper and 

 the two immersed, the insoluble cuprous salt was also deposited 

 upon the platinum. Attributing this result to the electrolysis of 

 the cupric salt by a feeble current, they tried the effect of a zinc- 

 platinum cell excited by. common water and with two platinum 

 electrodes in the cupric chloride. Cuprous chloride appeared at 

 the negative electrode and chlorine at the positive. An ordi- 

 nary Grove's cell also gave cuprous chloride for the first two or 

 three minutes, but afterwards metallic copper. A zinc and a 

 platinum plate, were joined and immersed in the cupric chloride ; 

 cuprous chloride was deposited upon the platinum, the edges 

 behig also incrusted with metallic copper. With magnesium in 

 place of the zinc, a larger proportion of copper was obtamed. 

 Mercuric and ferric chlorides being analogous to those of copper, 

 induced the authors to experiment with them also. Precisely 

 analogous results were obtained, mercurous and ferrous chlo- 

 rides appearing at the negative electrode.— A communication 

 was made by Prof. Guthrie on " Salt Solutions and attached 

 Water." Continuing the direction of research previously indi- 

 cated, and the results of which were communicated to the 

 Society in November last, the author described the following 

 facts : — Contrary to the generally received opinion, the minimum 

 temperature attainable by mixing ice with a salt is very inde- 

 pendent of the ratio of the two and of their temperature, and of 

 the state of division of the ice. The temperature of a mixture 

 of ice and a salt is as constant and precise as the meltmg-pomt 

 of ice." The nine salts resulting from the union of potassium, 

 sodium, and ammonium, on the one hand, and chlorine, bromine, 

 and iodine on the other, were examined in reference to their 

 ciyohydrates, the temperatures of the formation of which range 

 from - 28 to — 1 1. For the same halogen, sodium salts assume 

 less water than ammonium, and aramonmm less than potassium. 

 For the same metal, iodine salts assume less water than bromine, 

 and bromme salts less than chlorine. The result of the examination 

 of thirty-five salts establishes the identity of the temperature at 

 which the cryohydrate is formed with the temperature got by 

 mixing the salt with ice. Only two apparent exceptions to this 

 identity have been as yet observed. '1 he temperature at which a 

 cryohydrate is formed is, with similar salts, lower, according 

 as it assumes a less molecular ratio of water. There appear to 

 be no exceptions to the rule that the lower the temperature got 

 by mixing the salt with ice, the lower the molecular ratio of 

 water. Tlie temperature of incipient solidification of spirits of 

 wine of different strengths was also examined. It was found 

 that from spirits containing more water than the four hydrate, 

 pure ice was separated, and that the temperature gradually sank 

 to - 34° C, when the ratio of the four hydrate was reached. 

 Thence the temperatuie remained constant, and the whole 

 solidified into a hard mass. When a spirit richer than this cryo- 

 iiydrate is cooled, the cryohydrate separates, and a stronger and 

 stronger spirit is left, which ultimately defies the source of cold 

 (solid carbonic acid) ;to solidify it. Prof. A. Duprc's experi- 

 ments regarding the maximum temperature produced on di- 

 luting alcohol are thus singularly confirmed. For this experi- 

 menter showed that this very four molecule ratio produced 

 the greatest heat in its formation. Ethylic ether, which dis- 

 solves water and is dissolved by it, seems to form a definite 

 cryohydrate. Water saturated with ether solidifies at— 3°C. 

 without separation of etlier. The icy mass when ignited burns 

 with a colourless flame, the heat of which just suffices to melt 

 the ice, 



Paris 

 Academy of Scietices, Jan. 18. — M. M. Fremy in the chair. 

 — The following papers were read : — Un the saline matter which 

 the sugar-beet takes up from the soil and from manure, by M. 

 E. Pcligot ; experiments which the author made with ten speci- 

 mens of beet, all treated ditferently with regard to soil and ma- 

 nures, and tables of results obtamed w hen analysing their ashes. 

 ■ — On the temperatures under turf or naked ground during the 

 late frost, by MM. Becquerel and E. Pecquerel.— A note by 

 M, de Lesseps, on a project of communication between France 

 and England, by means of a submarine tunnel, with an extract 

 of a detaUed account of this project as presented to the French 

 National Assembly. M. Dupuy de Lome ihen spoke against 

 this project, and expressed himself in favour of a ^channel rail- 

 way ferry. — On the rigime of the principal rivers in the north, 



centre, and south of France, by M. Belgrand. — A note on M. 

 Gosselin's paper of the last meeting (see Nature, vol. xi. p. 

 240) with regard to unmovable dressings of wounds, by M. 

 Oilier. Baron Larrey then made some further remarks on the 

 subject. — On the first method of Jacobi for the integration of 

 equations with partial derivatives of the first order, by M. G. 

 Darboux. — On a system of tangential co-ordinates, by M. Casey. 

 — On the deposits of flint implements near Precy-sur-Oise, and 

 the presence of great pachydermata in the diluvium of the 

 same locality, by M. E. Robert. — A note by M. de Lontin, on 

 his ameliorations of dynamo-electric machines. — A note by M. 

 Bonneil, on an aeronautical apparatus. — A note by M. E. Duche- 

 min, on a new compass that can be used on the surface of liquids, 

 and gives the lime by the sun. — A note by M. C. Beuchot, on 

 the application of steam for canal and river navigation. — On the 

 causes of wear and tear and explosions of steam-boilers, by M. F. 

 Garrigou. — MM. Blandin, Baruzzi, Mosca, andGuillaumont, sent 

 some communications on Phylloxera. — The Minister for Foreign 

 Affairs transmitted to the Academy some documents received 

 from the French Consul at Mauritius, on the results obtained by 

 Lord Lindsay in the observation of the transit of Venus. The 

 French Consul at Honolulu sent some details on the same sub- 

 ject with regard to observations made by English expeditions at 

 Honolulu, Hawai, and Kanai. — A letter from the Minister for 

 Agriculture and Commerce, drawing the attention of the Academy 

 to the steps that ought to be taken to pievent the invasion into 

 France ot the fly Doryphora, which attacks the potato plantations 

 in the United States. — On the notion of general systemsof algebraic 

 or transcendent surfaces, deduced from that of iiiiplcxes of sur- 

 faces, by j\l. G. Fouret. — On the stellar system, 61 Cygni, stars 

 physically related, the relative motion of which is not an orbit 

 but rectilinear, by M. Flammarion. — Account of the discovery of 

 asteroid (141), at the Paris Observatory, by M. P. Henry. — On 

 the ammonia in the atmosphere, by M. A. Schloesing. — 

 Researches by M. Miintz, on the respiratory functions of fungi. — 

 On the decomposition of Fehling's liquor, and the admixture of 

 glucose in the presence of sugar, by MM. P. Champion and H. 

 Pellet.— On the pulsations of the heart, by JI. Marey. — On the 

 carrying along of air by a steam or air jet, by M. F. de Romilly. 

 — On the phenomena of mineral and organic localisation with 

 animals, and their biological importance, by M. E. Heckel.^ 

 On the development of Fteropoda, by M. H. Fol. — The neu- 

 tralisation of the acidity of chloral hydrate by carbonate of soda 

 retards the coagulation, while it preserves the physiological 

 properties, by M. Ore. ^Researches on the silicified plants of 

 Autun and Saint-Etienne, by M. B. Renault, witli special refer- 

 ence to the genus Botryopteris. — On the influence of forests upon 

 rivers and tlie hygrometric state of the atmosphere, by M. L. 

 Fautrat. — On the breaking of vessels by the ireezing of water, 

 by M. A. Barthelemy. — During the meeting the Secretary 

 announced the sad loss the Academy had sustained through the 

 death of M. d'Omalius d'Halloy, of Brussels, correspondent of 

 the Academy's Mineralogical Section. INL C. St. Claire-Deville 

 then spoke a few words in memory of the deceased. 



CONTENTS Pack 



The Makqims of Salisdurv on Scientific Education 241 



South American Travel (/(^///i ///iM^raZ/OTu) 241 



MoGGKiDGE's " Harvesting Ants AND Teap-eook Spiders" . . . 245 



TheUnionid^ 246 



Our Book Shelf: — 



Dr. le Bon's " Human Physiology " 246 



Letters to the Editor : — 



Fossil Remains of the Fallow Deer found in Malta —Prof. A. Leith 



Adams =47 



Electric Conductivity of Nerves —Dr. John Drvsdale .... 247 



Kirkcs' Physiology.— E. Prideaux 248 



The Rhinoceros in New Guinea. — Alfred O. Walker . . . . 24S 



Thomson's" Malacca."— W. L. Distant 24S 



Bees and Flowers.— Mary J. Plaer 248 



Iron Pyrites— Curious Phenomenon.— Frederic Case 249 



Our Astronomical Column : — 



Anlares as a Double Star 249 



The "Temporary Stars "of Tycho Erahe and Kepler 249 



The Zodiacal Light 249 



Planetary Theories. By M. Levereier 249 



Russian Forests • 251 



The India Museum 252 



Umuellula, or Cluster Polyp 252 



Science in the Argentine Republic 253 



Notes ^53 



On the liluscuLAK Mechanical Work done before Exhaustion. 



By Frank E. Nipher : . 256 



Scientific Serials 257 



Societies and Academies 25S 



