262 Scientific Intelligence. 
liquid portion from the granular mass, add repeatedly small portions of 
waterto the granular mass and decant, until the residue of bisulphate is 
of an orange color. _ Unite the portions decanted, concentrate by evap- 
oration, precipitate the chromic acid by sulphuric acid, throw it upon a 
funnel and let it drip, spread it on porous bricks, redissolve and crystal- 
ize. Inthis way large crystals of the pure acid can be obtained. The 
solution of chromic acid in sulphuric acid is a powerful oxydizing oR 
J. LS 
16. Preparation of the Phosphuret of Nitrogen; (Rap. ninseil de 
Berz., 1845, p. 40.)—M. Balmain has pointed out the following method 
vehicle furnishes very readily the substance in question. Heat gently in 
_ a flask, chloramide of mercury, and then add phosphorus in small 
pieces so long as any reaction takes place. Agitate from time to time, 
and complete the operation by heating the bottom of the flask to red- 
ness. The sal-ammoniac, excess of phosphorus, and mercury, is vola- 
tilized, and the phosphuret of nitrogen remains behind. J. L. 8. 
1%. Economical Method for preparing the Protoxide of Copper; by 
M. Wirrsten, (Revue Scient., Feb., 1846, p.-258.)—Dissolve 1 part 
of sulphate of copper and 1 part of sugar of milk in 10 parts of water, 
and add to the cold solution a solution of caustic potash until the pre- 
cipitated hydrated oxide of copper is redissolved by agitating the liquid. 
The blue solution is heated in a water bath, it being kept constantly 
agitated. Ina very short time the color passes to a grayish green, and 
a precipitate begins to appear, which is at first brown, but becomes fi- 
nally of a cinnabar red color. So soon as this happens withdraw the 
vessel from the fire, and place it in cold water to facilitate its cooling; 
after which it is readily collected on a filter. If the action of heat be 
continued its color becomes changed. ? is ha. 8. 
18. Amount of Carbon expired by Man; by E. A. ScHarbINne, 
(Annal. der Chem. und Pharm., vol. lvii, p. 1.)—These researches 
have reference to the amount of this substance expired by the as 
well as by the lungs. 
in one hour. __| in one hour. 
; Grains. ai 
Adult of 28 years, ‘ ; 174-7 ee xs, 
Young man of 16 yore, 166-4 2°78 
Boy of 10 years, 9 1:90 
bea girl of 19 years, * 193-7 ds, BRO 
henner i ie ere 
.L.8. 
19. Mode a siviing plates of Zine; by M. Warpetz, (Revue 
rigs 257. ideo Geapenss a ae 
