Carbonic Acid and Ammonia. 8} 
this increase cannot be ascribed to any 
other cause than the chemical union of the 
acid and the ammonia; for, Sir H. Davy 
and I have both found in constructing our re- 
spective tables of ammoniacal solutions, that 
no increase of gravity is observed in mixing 
these solutions with water. 
Again, 1 mixed a solution of muriate of 
ammonia and carb. of potash (of commerce) 
together, in such proportion as mutually to 
saturate each other, so that muriate of pot- 
ash and subcarbonate of ammonia must have 
been formed together ; the mixture was dis- 
tilled till all the ammonia was drawn over. 
The distilled liquid had its elements in the 
proportion of asubtricarbonate. I next took 
a solution of subcarbonate and distilled it in 
like manner; this also afforded a subtricarbo- 
nate and the residuary liquid in the retort was 
as near as possible a subpentacarbonate. 
About the same time I distilled a solution 
of carbonate of ammonia; it afforded a sub- 
carbonate and left in the retort a very weak 
carbonate of ammonia. 
On all these occasions of distillation the 
receivers were more or less open to the atmo- 
sphere; of course there was loss both of acid 
and alkali; but it appears that in all cases 
where heat is applied to the liquid solutions, 
