198 An Analysis of two Mineral 
hardly affected by it? To this it might, perhaps, 
be a sufficient reply, that it is unreasonable to op- 
pose a mere analogy to the direct evidence of the 
senses ; particularly in a new case, where we have 
found some of the analogies best established in che_ 
mistry actually to fail—But let us recur once more 
to experiment. 
I formed again some oxygenated muriat of iron. 
I suffered the acid to remain on the oxyd about 
twenty-four hours; then poured off the liquor, and 
evaporated the salt to dryness to expel the superfluous 
acid: the salt, which deliquesces instantly on cool- 
ing, was re-dissolved in a little distilled water. 1. I 
tried the solution with the acetite of lead: not the 
smallest cloud was produced. 2. The solution was 
then tried with nitrat of silver: a little white curdy 
matter was formed. 9. A tea-spoonful of the solu-: 
tion was diffused through two or three ounces of 
distilled water, and then tried with nitrat of silver: 
a very slight cloud was formed and a minute purple 
precipitate fell, but not till after some hours. The 
appearance was not so strong, nor the precipitate so 
copious, as when nitrat of silver is dropped into or- 
dinary rain water.—These experiments evince that 
this salt either does not decompose the salts of lead 
and silver, or that the new compounds are soluble 
in water. The first is absolutely conclusive: as to 
the small appearance of decomposition in experi- 
ment 2 and 3, be it considered how difficult it is to 
