the Attractive Powers of Mineral Acids . 19 
being as 1 to f , or at leafl: as 1 to and a ftrong heat muft 
alfo be applied. I could never diflolve the whole of any quan- 
tity of copper ; but to diflolve a given quantity of it, a ftill 
greater mull be ufed in the proportion of nearly 28 to 100, 
though this refiduum alfo is foluble by adding more acid. 
When copper has been dephlogifticated in this manner, a folu- 
tion of it is obtained by adding warm water to the dephlogifti- 
cated mafs. 
The dephlogiftication of 128 grs. of copper treated in this 
manner affords 1 1 cubic inches of inflammable air, and nearly 65 
of vitriolic air. When I obtained inflammable the acid was a 
little more aqueous. The reafon why copper cannot be dephlo- 
gifticated by dilute vitriolic acid, nor even by the concentrated, 
without the afliftance of a ftrong heat, as iron is, appears 
deriveable from its much ftronger attraction to phlogifton, and 
the much greater quantity of it which copper contains, as will 
hereafter be feen. Hence 
100 grs. of vitriol of copper contain 27 of copper, 30 of 
acid, and 43 of water, of which it lofes about 28 by evapora- 
tion or flight calcination. 
The folution of 100 grs. of copper affords 373 of blue 
vitriol. 
Copper in nitrous acid . 
loo grs. of copper require 130 of real nitrous acid to diflolve 
them. If the acid be fo far diluted as that its proportion to 
that of water be as 1 to 14, the affiftance of heat will be necef- 
fary, otherwife not. This folution aflords 67 i cubic inches of 
nitrous air. 
The calces of copper are alfo foluble in this acid. 
D 2 Copper 
