so 6 Mr. Chevenix's Analysis of 
This led me to imagine that I could perhaps, by fire, dissi- 
pate not only the water of crystallization, but that contained 
in the hydrate ; and leave the acid, if a potent one, still in the 
salt. But I found that the affinity of the alkali, acting upon 
the acid, had, in the humid way, determined an order of com- 
bination not to be effected by heat ; for, even sulphuric acid 
was expelled, before the water of the hydrate could be com- 
pletely dissipated. Upon reflecting on the fixity of acids, I 
could find none so proper for this experiment as the phos- 
phoric. I therefore prepared some artificial phosphate of cop- 
per, by precipitating the nitrate of that metal by phosphate 
of soda. When washed and dried, it was in the form of a fine 
bluish green powder, among which, many crystals were dis- 
cernible, almost to the naked eye. 
One hundred parts of this, exposed to a gentle red heat, became 
of a much paler green, but passed intirely to brown when the 
temperature was sufficiently elevated. I had then a brown 
phosphate, not of hydrate, but of oxide of copper, and from 
which no acid had been volatilized. Its loss of weight was 
wholly from the water which had been expelled, and amounted 
to 15,5. Its other proportions I found, by further analysis, 
to be 35 of phosphoric acid, and 49,5 of oxide of copper. It 
is not, however, to be concluded from this, that there are really 
13,5 of water of crystallization, in bluish green phosphate of 
copper. We must recollect, that it is a phosphate of hydrate of 
copper * and that 49,5 of oxide demand 1 2 of water, to exist in 
that state ; 3,5 therefore are the amount of the water of crystal- 
lization ; and its order of union may, with more propriety, be 
thus stated : 
