24 Experiments and Observations on 
The solution can be made to imbibe its own 
bulk of carbonic acid gas, the same as water, 
but no more: so that a supercarbonate of am- 
monia does not seem to exist, at least ina li- 
quid form. A saturated solution of 60° con- 
tains a little more salt than one at 32¢, from 
which circumstance the salt may be crystal- 
lized in a small degree on cooling. If a 
solution be attempted above 80 or 100°, the 
salt is rapidly decomposed; part of its acid 
escapes and a subcarbonate remains in solu- 
tion. When the solution is treated with so- 
lutions of salts of lime, no precipitation nor 
cloudiness ensues; this distinguishes the car- 
bonate from the subcarbonate of ammonia. 
When a due proportion of carbonate of am- 
monia is added to lime water, the lime is 
precipitated a carbonate, and just half the 
test acid is required to saturate the ammonia 
in the liquor that would have been required to 
saturate the lime. 
Such are some of the more remarkable pro- 
perties of the carbonate of ammonia. 
It is worthy of remark that carbonate 
of ammonia, which in the dry state is com- 
paratively a fixed salt, yet when in solution 
it is easily decomposed by heat. The two 
elements, carbonic acid and ammonia, are. 
both volatile and disposed to assume the elas- 
