20 Mr. Smithson's chemical Analysis 
On extraction of the saline part by distilled water, a fine 
powder remained, which, after ignition, weighed 5.8 grs. and 
was quartz. 
The saline solution afforded, on crystallization, only vitriol 
of zinc. 
These crystals therefore consist of, 
Quartz - - 0.250 
Calx of zinc - 0.683 
Water - 0.044 
o-977 
Loss - - - 0.023 
1.000. 
The water is most probably not an essential element of this 
calamine, or in it in the state of, what is improperly called, 
water of crystallization, but rather exists in the crystals in fluid 
drops interposed between their plates, as it often is in crystals 
of nitre, of quartz, &c. Its small quantity, and the crystals not 
falling to powder on its expulsion, but retaining almost per- 
fectly their original solidity, and spathose appearance in the 
places of fracture, and, above all, preserving their electrical 
quality wholly unimpaired, which would hardly be the case 
after the loss of a real element of their constitution, seem to 
warrant this opinion. 
If the water is only accidental in this calamine, its composi- 
tion, from the above experiments, will be, 
Quartz - 0.261 
Calx of zinc - 0.739 
1.000. 
I have found this species of calamine amongst the productions 
of Derbyshire, in small brown crystals, deposited, together with 
