232 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. On Cryohydric Temperatures. — The experiments of Guth- 

 rie on the cryohydric points of systems of mixed salts, have 

 been repeated and the results discussed by Schreinemakers. 

 He finds that when the two salts do not form a double salt, the 

 cryohydric point of the mixture is lower than the cryohydric 

 point of a solution in equilibi*ium with either of the salts sepa- 

 rately. Moreover when a double salt is formed and this salt de- 

 composes on solution, such for example as Pbl„, KI, (H 2 0)„, the 

 cryohydric temperature of a solution in equilibrium with the 

 double salt and one of its components is lower than the cryo- 

 hydric temperature of a solution in equilibrium with this com- 

 ponent alone; and the cryohydric point of a solution in equilib- 

 rium with the double salt and the component which is not depos- 

 ited is lower than that of a solution in equilibrium with the 

 double salt and the component which is deposited. Again if the 

 double salt formed dissolves homogeneously without decomposi- 

 tion, as is the case for example with CuS0 4 (NH 4 ) 2 S0 4 .(H 2 0) 6 , 

 the cryohydric temperature of a solution in equilibrium with the 

 double salt and one of its components is lower than the cryohy- 

 dric temperature of a solution of the double salt alone. — Zeitschr. 

 Fhysikal. Chem., xii, 73, July, 1893. g. r. b. 



2. On the use of Phenanthrene as a Solvent in Cryoscopic de- 

 terminations. — In determining cryoscopically the molecular mass 

 of indole in a naphthalene solution Gareixi and Ferratini 

 obtained anomalous results which they attributed to the forma- 

 tion of solid solutions of indole in the crystallizing hydrocarbon; 

 this formation being influenced apparently by the similarity in 

 constitution between the two. To test this hypothesis, they ex- 

 amined a liquid solution of carbazole in phenanthrene, and found 

 that the crystals which separate on cooling this solution, contain 

 a large quantity of the dissolved substance, amounting, when the 

 solution contained 7*5 per cent of carbazole, to 11*42 per cent. 

 Other things being equal, however, the authors regard phenan- 

 threne a better solvent than naphthalene for use in determining 

 molecular masses by the cryoscopic method ; since its high depres- 

 sion constant! 120, makes it possible to obtain accurate results 

 with very dilute solutions and its lower volatility renders it 

 easier of manipulation. — Gazetta Chim. Pal., xxiii, (1) 442; J. 

 Chem. Soc., lxiv, ii, 512, Nov. 1893. g. f. b. 



3. On the Vapor-pressures of solutions of Sulphur and Phos- 

 phorus in Carbon disulphide. — By enclosing solutions of sulphur 

 and of phosphorus in carbon disulphide, in a space exhausted by 

 a Sprengel pump, and measuring the vapor-pressure by means of 

 a manometer, Gugleelmo has determined the molecular masses of 

 these elements. At ordinary temperatures, a glass apparatus was 



