37$ Dr. F ordyce o« the Cause of the additional Weight 
and after the saturation took place ; the deficiency of weight 
afterwards being the weight of the aqua kali puri applied to the 
acid for the saturation ; this was 10147 grains. I also weighed 
the vessel with the acid before the aqua kali puri was poured 
in, and afterwards ; and found the increase of weight to be 
exactly the same as the weight of the aqua kali puri and juice 
of violets, so that nothing was lost during the operation. 
This experiment was three times repeated, taking the point 
of saturation from the eye. The quantities of aqua kali puri 
employed were found to be 10147 grains, 10145 grains, 10150 
grains. 
I took 10148 grains, being the mean of the three experi- 
ments, and applied it to 1000 grains of the same vitriolic acid ; 
evaporated the water to dryness, and heated it to a red heat, 
to drive off’ the whole of the water ; and found 978 grains of 
kali vitriolatum remaining. By this means I ascertained the 
quantity of kali vitriolatum produced from 1000 grains of the 
diluted vitriolic acid, when saturated with kali. 
I took 1000 grains of the diluted vitriolic acid, and put it 
into a vessel, of the form in the figure annexed (Tab. X.), I 
added zinc to it until it would dissolve no more ; I caught, 
during the solution, the inflammable air, which weighed 9 
grains, and whose specific gravity was, to atmospheric air, as 
somewhat l^ss than 1 to 12. The vessel contained the whole 
of the acid and the zinc in the globular part marked A, the 
acid being introduced by a funnel. 
The solution was terminated in five days ; when part of 
the tube D being broke off’, it was left to stand for four-and- 
twenty hours, to allow the inflammable air remaining in the 
