28 Experiments and Observations on 
quor when tested is found neutral. But if the 
common subcarbonate with defect df, base be 
used, the decomposition is not complete, sul- 
phate of lime and carbonate of ammonia re- 
main in the liquor, which if tried by the co- 
lour test, is found alkaline. In this case, 
however singular the fact may appear, T find 
it to be true, that if ammonia be added to this 
alkaline liquor, it becomes neutral. For, the 
ammonia converts the carbonate into subcar- 
bonate, in which state it is capable of acting 
on the sulphate of lime. — 
The true subcarbonate above described 
may be obtained in the solid form in two 
ways: first by subliming the common subcar- 
bonate and taking the first product before it — 
has had any communication with the air; and 
second, by taking a saturated warm solution 
of the common subcarbonate and adding a 
sufficient quantity of ammonia (to be found 
by trial) to raise the proportion of ammonia 
to that of acid, as 12 to 19.4, nearly; then 
suffering the solution to cool the salt will be 
precipitated copiously. But for purposes of 
chemical investigation it will be found suffici- 
ent to procure a liquid solution of the sp. gr. 
1.086, and such that 100 measures of it are 
capable of saturating 100 measures of test acid; 
for then it will contain 6 grains of ammonia 
and 9.7 of acid per cent. 
