termed triple Prussiates. 
533 
Analysis offerruretted Chyazate of Potash. (-Triple Prussiate of 
Potash. ) 
I cannot find that this salt has ever been completely ana- 
lysed : the only person who to my knowledge has even par- 
tially effected it is Proust, who confined himself to ascertaining 
the quantities of water and of black oxide of iron which it 
contains, and which he states to be in the loo parts. 
Water - lo 
Black oxide of iron 17 
I have made similar experiments to those from which he drew 
the above conclusions, and added others of my own ; the fol- 
lowing are the particulars of these experiments with the results 
which I have obtained. 
A. 100 grains of the crystallized salt, finely pulverized > 
were kept for six hours at the temperature of 212®, by this 
treatment they were reduced in weight thirteen grains ; they 
were afterwards heated for one hour at the temperature of 
40®, but they did not suffer any further loss. 
B. 100 grains of the same salt were heated with weak sul- 
phuric acid until all the Prussic acid that could be expelled as 
gas was separated, the rest of the Prussic acid combined dur- 
ing the process with the oxide of iron contained in the salt, 
and formed ferruretted chyazate of protoxide of iron (white 
prussiate of iron), which I afterwards changed into ferruretted 
chyazate of per-oxide of iron (blue prussiate of iron) by the 
addition of a little weak nitric acid ; it was then thoroughly 
washed and dried at 212*, it weighed after this thirty-five 
grains. These thirty-five grains, as may be seen by the 
analysis which I have made of the ferruretted chyazate of 
MDCCCXIV. 3 Z 
