204 An Analysis of two Mineral 
into this I dropped a little sulphuric acid; by de- 
grees a large quantity of sulphat of lime was sepa- 
rated. Muriatic acid was dropped into the same 
liquor, but it did not separate any thing. ‘The oxy- 
genated muriat of iron possessed the same property, 
but in so small a degree, that here again I am -in- 
clined to attribute this power to a little manganese | 
attached to the iron. It follows from these facts, 
that the large quantity of sulphat of lime is kept in 
solution by the salt of manganese. And a fur- 
ther examination of the residuum itself shews that it 
contains the triple.salt of manganese and iron. © 5. 
Some of the residuum was perfectly edulcorated and 
sulphuric acid was dropped upon it: the vapours of 
muriatic acid arose, and were rendered evident by 
paper moistened with ammoniac or with simple 
water. . To the sulphuric acid, which was used in 
this experiment, was added some distilled water and 
the liquor was filtrated: it was then saturated with an 
alkali;-a small precipitate fell, which was proved 
(by the usual methods) to contain both manganese 
and iron. | . ) yints 
6. Ihave noticed a variation (2.) in the effect| of 
muriatic acid when added to the water. I have ob- 
_ served a similar variety in the residuum itself; which 
is, that sometimes it has been found soluble in the 
muriatic acid: when this happens, the addition of an 
alkali precipitates the residuum in its original cry- 
stalline form, and this it does before the acid is sa- 
