Chemistry and Physics. 139 
SCIENTIFIC INTELLIGENCE. 
I. CHEMISTRY AND PuHysics. 
On the Amount of Carbonie gas in the Atmosphere.— 
i 
Trucuot has recently made a series of determinations of the 
amount of carbonic gas in the atmosphere. His method of analy- 
,000 ; a number very near that usually received. 5th, that the 
proportion of carbonic gas diminishes with the altitude, thus : 
Station. Altitude. Wt. CO, ols. of CO. 
to the liter. in 10,000 of air. 
Clermont-Ferrand, 395" 0°623" 3-13 
Puy-de-Déme, 1446 0°405 2°08 
Pic-de-Sancy, 1881 0°342 17? 
— C. R., \xxvii, 675. Bull. Soc. Ch., TI, xx, 494, Dec., 1873. 6. F. B. 
de- 
ments upon the decomposition of hydrogen arsenide. He pre- 
ared the gas from sodium arsenide by the action of water, or 
preferably of very dilute acids; the sodium arsenide itself being 
h 
the cold, a red-brown powder of arsenous phosphide is thrown 
down, formed as follows: 
PCl,+AsH,—(HCl),+-PAs. : 
Thi Substance, separated from the liquid and dried in a current 
of carbonie gas at 70° to 80° C., is a dark red-brown lusterless 
powder, containine 70°53 per cent of arsenic and 29°11 per cent 
of phosphorus, ater decomposes it, yielding a substance hay- 
ing the formula As,P,0,. It is insoluble in alcohol, a -_ 
= i e 1s- 
chloroform, and in sulphuric and hydrochloric acids. _C 
Solves it in small quantity. By nitric acid, it 
arsenic and phosphoric acids, Alkali-hydrates decompose it, pro- 
ducing hydrogen phosphide and arsenide, arsenite and phosphite 
arsenic acids, In close vessels, it decompose 
Phosphorus and arsenic, which sublime. The author also observes 
