~ 
462 On definite Proportions. 
ferent distribution of the oxygen among different portiong 
of the radical, is common to this with the other imperfect 
acids, 
4, Other Nilrous Salts. 
I have attempted to prepare other nitrous salts by means 
of the nitrite of the protoxide of lead, mixing it with various 
sulphates; but I have hitherto obtained little more than a 
conviction of the possibility of their being exhibited. When, 
for example, I mixed the sulphate of the oxide of copper 
with this nitrite, I obtained a grass green solution, which 
when exposed to the air deposited by degrees subnitrate of 
the oxide of copper, and finally, after several weeks, became 
again blue. The same happened still more rapidly when 
heat was applied. I attempted to prepare this salt from the 
nitrate of the oxide of copper, by digesting it on copper ; 
but I could not succeed in obtaining a nitrous salt, proba- 
bly because the nitrous acid forms no such subsalt with the 
oxide of copper as with the protoxide of lead. 
Nitrite of ammonia, prepared in the same manner as the 
nitrite of the oxide of copper, 1s a colourless salt, which 1s 
decomposed at a temperature not very high. Between 40° 
and 50° [104° and 122°] the solution continually emits 
bubbles of pure nitrogen; when heated to the boiling point, 
it froths very considerably, and the extrication of gas 1s 
more rapid; and as long as the solution is not too much 
edhiesntrated nothing but nitrogen gas is produced, and 
the salt remains in a neutral state. I attempted to obtain 
it ina dry form, leaving the solution exposed in shallow 
dishes to a current of dry air; and f obtained a saline mass 
indistinctly crystallized, which resembled the nitrate of am- 
monia. When melted in a small retort, it afforded much 
gas, and a quantity of water strongly impregnated with ame 
monia. The gas obtained was not reddened by oxygen, and 
had all the properties of the nitrous oxide. 
These appearances are easy to be explained. The nitrous 
acid neutralises a quantity of the base, which contains 3 as 
much oxygen as the acid. The oxygen of the acid, "exe 
clusive of that of the nitrogen, is then exactly sufficient to 
change into water all the hydrogen which is produced du- 
ring “the further oxidation of the ammonia, while the 
nitrogen of the acid and that of the ammonia are disengaged 
together in the form of gas. The nitrite of ammonia is 
therefore decomposed, when its solution is not too much 
concentrated, into water and nitrogen, and perhaps this salt 
affords the cheapest and most certain mode of obtaining ni- 
trogen 
a Se 
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