] 
dry remained. 
On this, boiling distilled water was repeatedly poured, until 
it no longer changed the colour of litmus paper, and was de- 
void of taste. The undissolved portion was then dried, and 
made red-hot; after which it weighed 281 grains. 
C. I now mixed the 281 grains with 300 grains of dry car- 
bonate of potash, and exposed the mixture to a strong red heat, 
in a silver crucible, during four hours. The mass was loose, 
and of a greyish white : it was softened with water, and, being 
put into a retort, sulphuric acid was added to a considerable 
excess. The whole was then distilled to dryness, and, when 
a sufficient quantity of boiling water had been added, it was 
poured on a filter, and the residuum was well washed ; it was 
then made red-hot, and afterwards weighed 274.7 5 grains. 
D. The solutions of B and C were added together, and were 
much reduced by evaporation. Pure ammoniac was then em- 
ployed to saturate the acid, and a copious loose precipitate, of 
a pale yellowish colour was produced ; which, collected, edul- 
corated, and made red-hot, weighed 103.70 grains. 
E. The filtrated liquor of D was again evaporated, and 
carbonate of potash being added, a slight precipitation of earthy 
matter took place; which, by the test of sulphuric acid, proved 
to be some alumine which had not been precipitated in the 
former experiment : this weighed 1.20 grain. 
F. The 103.70 grains of D were completely dissolved when 
digested with nitric acid, excepting a small residuum of silice- 
ous earth, which weighed 0.90 grain. 
G. The nitric solution was evaporated to dryness, and a 
'0010-s: *' 
