[ 525 ] 
By which it appears that the fumes, which firfl: 
arofe without fire, are ftronger than the fecond, 
and the fecond than the third. 
It appears further, that the moft concentrated 
portion of the acid of fea fait is the moft volatile, 
and that in ftrength it is to the oil of vitriol men- 
tioned before, as 44 "t t0 3 1 * 
* In order to try the purity of the acid vapours, 
which were condenfed in the water, and of the 
acid, which diftilled into the bottle C, the follow- 
ing experiments were made, and are marked a, b, 
c, d. 
(a) Four ounces of the fpirit of fait of the 2d 
experiment, was perfectly faturated with 4^ of 
whiting. 
(b) Four ounces of the fpirit of fait of the 3d 
experiment, was perfectly faturated with 4J oi 
ditto. 
(c) As much water as contained 4 g of vapour 
of the 2d experiment, was faturated with 5 ^ of 
ditto. 
(d) As much water as contained 4 J of vapour 
of the 3d experiment, was faturated with 6 J of 
ditto. 
The reafon of ufing more whiting with fome 
than with others, was on account of the different 
ftrength of the acids ; and as there was a greater 
quantity of whiting than neceflary ufed in thefe 
experiments to faturate the acids, the undifiolved 
* This depends on the property of the acid of vitriol, and 
the acid of fea fait, combined with a calcareous earth ; for. this 
earth, combined with the acid of fea hilt, forms a very foluble 
fubftance ; whereas the fame earth, with the acid of vitriol, forms 
a fubftance infoluble (or almoft io), called felenite. 
part 
