202 An Analysis of two:-Mineral 
mained a large residuum which was not solublesex- 
cept in a great quantity of water. This has a ery- 
stalline form like sulphat of lime ;, and the usual re- 
agents shewed it, in fact, to contain both lime and 
sulphuric acid. But the weight of this residuum, 
from a gallon of water, was no less than 112 grains : 
a larger quantity than could be dissolved in a gallon 
of water, if it were pure sulphat of lime. If it be 
considered, that the water requires some evapora- 
tion’ before these crystals begin to separate, the pro- 
portion is still more increased: There must. be, 
therefore, something peculiar in the composition of 
the salt, or in the soluble powers of the water. 
Other experiments shew the same thing. 1. Sul- 
phuric acid dropped into the water precipitates co- 
piously sulphat of lime. This cannot be effected 
by the decomposition of muriat of lime; since we 
have already seen that no such salt is to be found 
(xrir.). Indeed, it cannot exist in the same solu- 
tion with sulphat of soda, as these salts decompose 
each other.* 2. Sometimes a more unexpected 
* It is astonishing that this fact should have been ne- 
glected, and that in recent publications. Mr. Schmeisser, 
in his Analysis of the Waters of Kilburn Wells (publish- 
ed in the Philosophical Transactions for 1792), has joined 
together sulphat of soda, sulphat of magnesia, and muriat 
of lime, as being contained in those waters, Dr, Garnett 
has also put into the composition of the sulphur-well at 
Harrogate sulphat of magnesia and muriat of lime; an er- 
