15 
of some Calamines . 
by carbonate of soda, and the filtered liquor let exhale slowly in 
the air ; but it furnished only crystals of muriate of soda. 
e. 10 grs. dissolved in acetous acid without leaving any resi- 
duum. By gentle evaporation, 20.3 grs. = 2.03, of acetite of 
zinc, in the usual hexagonal plates, were obtained. These crys- 
tals were permanent in the air, and no other kind of salt could 
be perceived amongst them. 
Neither solution of vitriolated tartar, nor vitriolic acid, occa- 
sioned the slightest turbidness in the solution of these crystals, 
either immediately or on standing ; a proof that the quantity of 
lime and lead in this solution, if any, was excessively minute. 
/. A bit of this calamine, weighing 20.6 grs. being made red 
hot in a covered tobacco-pipe, became very brittle, dividing on 
the slightest touch into prisms, like those of starch, and lost 5.9 
grs. of its weight = 0.286. After this, it dissolved slowly and 
difficultly in vitriolic acid, without any effervescence. 
According to these experiments, this calamine consists of, 
Calx of zinc - - - 0.714 
Carbonic acid - 0.135 
Water - 0.151 
1.000. 
The carbonates of lime and lead in it are mere accidental 
admixtures, and in too small quantity to deserve notice. 
Calamine from Somersetshire. 
a. This calamine came from Mendip Hills in Somersetshire. 
It had a mammillated form ; was of a dense crystalline tex- 
ture; semitransparent at its edges, and in its small fragments; 
and upon the whole very similar, in its general appearance, to 
calcedony. 
