MISCELLANY. 
261 
and absorbs very considerable quantities of it. Sulphate of ammonia be- 
ing heated in this compound to about 322° Fahr., pure azotic gas, perfectly 
unmixed with nitrous or nitric oxide, was obtained. This experiment 
was varied by passing nitric oxide gas into concentrated sulphuric acid, 
mixed with sulphate of ammonia, and heated from about 300° Fahr. to 
392°. The nitric oxide was decomposed as in the preceding experiment, 
and pure azotic gas was obtained ; it is mixed with nitric oxide only 
when the disengagement is too rapid. M. Pelouze is of opinion that this 
method of preparing azotic gas may be advantageously employed. 
Journ. de Pharm. 
Concentration of Nitric Acid, by means of Sulphuric Acid. By M. 
Pelouze. — It is stated in different chemical treatises, that concentrated 
sulphuric acid, decomposes nitric acid into water, with which it combines, 
and hyponitrous acid. M. Pelouze doubted the accuracy of this statement, 
and was convinced that it was erroneous, by observing nitric acid distilled 
from a mixture of nitrate of ammonia, with great excess of sulphuric acid, 
at 212°. 
500 parts of concentrated sulphuric acid were mixed with 100 of nitric 
acid of specific gravity 1.448; the mixture was slowly distilled and yield- 
ed 88 parts of nitric acid of specific gravity 1.520 ; this product freed from 
red vapor by a gentle heat was mixed with six and a half times its weight 
of concentrated sulphuric acid, unaccompanied by any sensible increase of 
temperature. The mixture was colorless, and yielded very dense white 
vapors of nitric acid. When heated to a temperature which never ex- 
ceeded 302°, and was kept as near as possible to 212°, 82 parts of nitric 
aeid of specific gravity 1.520 were distilled ; its density remained 1.520, 
and its boiling point was from 185° to 188° Fahr. 
A third rectification with sulphuric acid effected no change either in the 
properties, density or color of the nitric acid.-— Journ. de Pharm. t. xxvij. 
p. 275,) per London, Edinburgh, and Dublin Fhilosoph. Mag. 
On the Microscopic Characters of healthy Milk. — By Professor Von 
D'Outrfpont, of Wurzburg. — He has recently put to the test some of 
M. Donne's statements with reference k to the characteristics of healthy 
milk, and has arrived at somewhat different conclusions, though he fully 
confirms Donne's statements with reference to the difference of the cor- 
puscles in the colostrum and milk. 
Professor Von D'Outrepont found that in the greater number of instances 
the peculiar granular bodies of the colostrum {corps granuleux) disappear- 
ed on the third day after delivery, and not on the sixth or tenth as stated 
by Donne. Even in those cases, however, in which they could still be 
detected on the tenth or twelfth day, the milk produced no injurious effects 
on the infant ; nor did it indeed in some instances in which the milk re- 
