378 Miscellanies. 



space a temperature of ^- 49.85° cent., which differs only by one 

 seventh of a degree from the result of Fourier, deduced from the laws 

 of heat radiated from the mass of the earth, the temperature of which 

 he supposed to have reached its asymptotic state of absolute unchange- 

 ableness on the whole. Without believing in the identity of light and 

 heat, or in the certainty of our photometric knowledge, I have thought 

 it not etirely void of interest to see what results, in relation to this 

 point, could be obtained from Lambert's statements, in regard to the 

 absorption which takes place in a ray of light passing from the zenith 

 through the whole atmosphere, calculated on the supposition that the 

 differential of the increase of temperature is always proportional to 

 that of the absorbed light. By this process I have obtained for the 

 required temperature — 50.35°. I was most agreeably surprised by 

 so remarkable an agreement between both of these results and that 

 which Fourier derived from principles so different ; and it affords an 

 additional reason why the function I have given for the temperature 

 should be taken into due consideration. The immediate results of 

 the same are, that the temperature diminishes with a constantly di- 

 minishing velocity, as we ascend in the atmosphere, and that even at 

 a given height, this velocity is greater, the higher the temperature at 

 the earth's surface. — Idem. 



10. Sulphuret of Cyanogen. — Lassaigne,* by mixing perchloride of 

 sulphur, with twice its weight of cyanide of mercury, and leaving 

 them some days in a flask, has obtained a colorless crystalline subli- 

 mate, which is a new compound of sulphur and cyanogen, having the 

 following properties : it sublimes spontaneously in rhomboidal scales, 

 which powerfully decompose light. It is very volatile, has a pungent 

 odor, and seems to act with considei-able energy on the animal econ- 

 omy. Exposed to air and light, it soon becomes yellow. It dissolves 

 both in water and alcohol. Its solution in water reddens litmus, and 

 gives a red color to the salts of iron. This is the only compound of 

 these two elements which has hitherto been obtained in an isolated 

 state. It contains twenty four per cent, of sulphur, and may there- 

 fore be considered as a disulphuret of Cyanogen; we have therefore 

 three known compounds of sulphur, and cyanogen. 1st. 1 atom of sul- 

 phur -f- 2 atoms cyanogen. — 2d. 2 atoms sulphur -\- 1 atom cyano- 

 gen. — 3d. 4 atoms sulphur + 1 atom cyanogen. 



The first is the sulphuret of cyanogen of Lasssaigne. The second 

 the base of the sulphocyanic acid of Porret. 



* Poggendorf 's Annals, XIV. 532. 



