24 -Mr. Smithson's chemical Analysis 
1000 parts of the compound salt of carbonate and hydrate of 
zinc consist of, 
fCarbonic 
Carbonate of zinc 400 =< 
acid = -^1 — - 
3 
Calx of 
zinc =1^ = 266^ 
Hydrate of zinc = 600 << 
L 3 
f Calx of 
i • OOO X 3 
I zinc — — — — 
4 
600 
450 
= — 716 
- 150 
1000. 
Great as is the agreement between the quantities of the last 
column and those obtained by the analysis of the Bleyberg 
calamine, (page 15,) it would be yet more perfect, probably, 
had there been, in this instance, no sources of fallacy but those 
attached to chemical operations, such as errors of weighing, 
waste, &c. but the differences which exist are owing, in some 
measure at least, to the admixture of carbonate of lime and 
carbonate of lead, in the calamine analysed, and also to some 
portion of water, which is undoubtedly contained, in the state 
of moisture, in so porous and bibulous a body. 
It has also appeared, in the experiments on the Mendip Hill 
calamine, that acids indicate a greater quantity of carbonic acid 
than fire does, by i - ^ o „ If we make this deduction for dissolved 
water, it reduces the quantity of carbonic acid in the Bleyberg 
calamine, to 0.1321. 
If we assume this quantity of carbonic add as the datum to 
calculate, on this system, the composition of the calamine from 
Bleyberg, we shall obtain the following results : 
w|*» 
