537 
termed triple Priissiates. 
I found that the contents of the retort had lost in weight 19.5 
grains, and that those of the receiver had gained 10.5, the 
mean between these two is 15 grains, which does not differ 
very materially from the quantity deduced from ascertaining 
the weight of all the other constituents of Prussian blue, con- 
sequently this latter method may be adopted without the 
hazard of any material error. 
Ferruretted chyazate of per-oxide of iron according to these 
experiments is composed of 
19.33 Black oxide of iron Ferruretted chyazic 
34.05 Elements of Prussic acid J acid A - 53-38 
Per-oxide of iron B 35.00 
Water D 11.^2 
100.00 
or if its composition be calculated from the quantity of per- 
oxide of iron afforded by its combustion, jointly with the 
quantity of ferruretted chyazate of potash required to form it, 
then it will consist of 
Ferruretted chyazic acid A 
5338 
Per-oxide of iron C 
33-47 
Water D - 
13-15 
. 
100.00 
These analyses by different methods agree together as nearly 
as could well be expected, the mean of the two is given below, 
which cannot, I think, be far from the truth. 
