390 Scientific Intelligence. 



solution thus obtained may be electrolysed ; and if a platinum 

 electrode be employed, a deposit of carbon is obtained at first as a 

 thin colored film and then as a deposit of graphite. The solution 

 itself reduces Fehling's solution and probably contains carbohy- 

 drates. On making a cell by means of a lead peroxide plate and 

 a carbon electrode, and on working under the conditions above 

 mentioned, the carbon acts as the soluble electrode. The cell 

 gave an electromotive force of 1*03 volts and yielded a constant 

 current until the lead peroxide was exhausted. — Chem. Centralbl., 

 i, 985, 1896; J. Chem. Soc, lxxii, ii, 241, June, 1897. G. f. b. 



5. On the conversion of Nitrites into Cyanides. — On heating 

 together sodium nitrite and sodium acetate, the mixture finally 

 explodes. Keep has shown that if the mass be mixed with dry 

 sodium carbonate before heating, it glows and becomes dark col- 

 ored, evolving hydrogen cyanide. It is then found to contain 

 sodium cyanide as follows : 



CH 3 . COONa + NaN0 2 =NaHC0 3 + NaCN + H 2 0. 

 About 25 per cent of the theoretical yield is obtained. Sodium 

 nitrite, heated with formate, gives only sodium carbonate ; while 

 with propionate it deflagrates and gives a small amount of cyan- 

 ide. If sodium acetate or cream of tartar be heated with potas- 

 sium nitrate a violent explosion occurs, cyanide and cyanate being 

 produced. Nitrite is probably at first formed and this by its 

 action on the acetate gives nitroso-acetate, giving hydrogen cyan- 

 ide and hydrogen-sodium carbonate. — Ber. Berl. Chem. Ges., xxx, 

 610-612, April 1897. g. f. b. 



6. Physics ; the Student's Manual for the Study Room and 

 Laboratory ; by LeRoy C. Cooley, Ph.D., Professor of Physics 

 in Yassar College. 12mo, pp. 448. New York, 1897. (The 

 American Book Company.) — This book combines very skillfully 

 class room and laboratory instruction. The principles it treats of 

 are clearly and accurately stated and it cannot fail to become a 

 valuable addition to the existing text-books on elementary physics. 



G. F. B, 



7. Action at a distance. — P. Drude in an extended article 

 discusses the mystery of gravitation, and is led to the conclusion 

 that, in order to discover its mode of action, we must seek it in 

 some hitherto undiscovered property of the ether, and he quotes 

 Maxwell's remark in an article on attraction in the Encyclopaedia 

 Britannica, "The answer to the question of how two bodies act 

 upon each other lies in the incitement of investigation of the 

 properties of the intervening medium." Hitherto we have recog- 

 nized only one property of a vacuum, that of the propagation of 

 light velocity. The author is hopeful that we shall discover other 

 properties of the so-called ether, which will enable us to build up 

 a system of units which will not depend upon the materials of 

 which the earth is composed but which will be connected with 

 the general properties of the ether. The mean free wave length 

 of the ether atom might serve for the measure of length, for 

 instance. The unit of time would then result from the velocity 

 of light.— Wied. Ami., No. 9, 1897, pp. 1-49. J. t. 



