286 Dr. H. Will on M. Reiset’s Remarks ° 
cally identical. Not having a microscope, I have not studied 
their physical characters minutely; but I suspect, from its 
aspect in the liquid in which it is formed, that the new oxide 
is crystalline. 
It is obvious that the above process furnishes an easy 
method of procuring a very pure oxide of silver, and of course 
the action of heat gives us the silver in the state of metal. 
It is, I conceive, applicable both to the manufacture of nitrate 
(in a state of absolute purity) and to the metallurgic process 
for obtaining pure silver. For both objects, it is a matter of 
no consequence, if some chloride should have escaped the 
action of the alkali. This chloride is left undissolved by the 
nitric acid, and is separated by filtration; while if the oxide 
(not quite free from chloride) be mixed with a little nitre or 
carbonate of potash, and fused, the whole silver is obtained 
with the utmost facility*. In order to give an idea of the 
ease with which the whole is performed, I may mention that 
I dissolved a half-crown, and obtained the whole of the silver 
it contained, within a very trifling fraction (chiefly decanted 
in the first washing of the chloride, but not lost), by the above 
process, within two hours, in a fused state. The silver was 
quite pure. There is no doubt that to chemists also an easy 
method of obtaining quickly pure oxide of silver, in a form 
much less hygrometric than the usual one, will be acceptable. 
It is particularly to be noticed, that if the chloride have 
ONCE BEEN DRIED, it is with great difficulty decomposed, even 
by a long boiling with potash. 
King’s College, Aberdeen, Jan. 20, 1843. 
LII. Observations on M. Reiset’s Remarks on the new 
Method for the Estimation of Nitrogen in Organic Com- 
pounds, and also on the supposed part which the Nitro- 
gen of the Atmosphere plays in the formation of Ammonia. 
By H. Witt, Ph. D.+. 
(THE method for the estimation of the nitrogen in organic 
substances described by Varrentrapp and myselft{ has been 
received by many chemists with the greatest approbation, as 
well on account of its simplicity as the accuracy and security 
with which results can be obtained. M. Reiset has however 
* In fact, this process, imperfectly performed, is an excellent prelimi- 
nary step, when a large quantity of chloride is to be reduced. The impure 
oxide requires so little alkali to complete its decomposition, that the cru- 
cible runs no risk. A little borax may be added as a flux. 
+ Communicated by the Chemical Society; having been read March 
21, 1843. 
} Annal. der Chemie, b. xxxix. 8.257. See also Philosophical Magazine 
for March 1842, p. 216. 
