termed triple Prussiates. 54c^. 
solution, these precipitates have rather a dark colour. I pro- 
ceed now to relate iny 
Analytical Experiments on the Red Tinging Acid. 
A. I find that whenever this acid is distilled, a portion of 
sulphur remains behind in the retort, and the acid that passes 
over into the receiver contains a little in solution, at the same 
time a portion of the acid disappears, so that it would be pos- 
sible, by repeated distillations, to destroy the whole of it. The 
nature of the new product produced by this repeated distilla- 
tion I have not investigated any farther than to ascertain that 
it did not contain any Prussic acid. The sulphur that was 
separated was not in the hydroguretted, but in the common 
state. 
B. Some of the red tinging acid was added to nitrate of lead, 
and an excess of nitric acid was poured into it. No precipitate 
was formed in the cold, but when heat was applied, a consi- 
derable action took place, attended with the escape of nitrous 
gas, and a copious white precipitate appeared, which, upon 
examination, proved to be sulphate of lead. 
C. Five grains of the white salt of copper before mentioned, 
prepared with the most scrupulous care, and which I knew by 
an analysis (to be presently mentioned) contained 1.84, grain 
of this acid in a dry state, were totally decomposed by nitric 
acid in which muriate of barytes had been previously dissolved: 
they afforded by this treatment a white powder, weighing after 
ignition 15.82 grains, which by the subsequent action of nitric 
acid were reduced to 8.86 grains, and were sulphate of barytes, 
which is equivalent to 1.20 grain of sulphur. 
D. Some of the red tinging acid was heated upon native 
MDCCCXIV. 4 B 
