290 
time of their fixing themselves in, or attaching themselves to, this 
substance, had been effected from a substance, in a state of igneous 
fusion. Their splendour, and their irridiscent surface, appear also to 
be at least, as easily accounted for by the agsncy of -water, as by 
that of fire. Mrs. Fulhame has detailed some very pleasing, and in- 
genious, experiments, -which bear very strong evidence in favour of 
this opinion of their aqueous origin. This lady impregnated pieces 
of silk with solutions of various metals, and exposed them, wetted 
with water, to the action of hydrogen, sulphuretted hydrogen, &c. 
in consequence of which they became covered by films of reduced 
metal; which sometimes, like the native sulphurets, displayed a 
variety of most lively colours. Even those metals, which were 
not capable of being precipitated, by the addition of sulphuretted 
hydrogen to their solutions, obtained, in this manner, their metallic 
splendour*. 
By these experiments, we are undoubtedly taught, that hydrogen 
as well as sulphuretted hydrogen, is capable of reducing the metals, 
even in the ordinary temperature of the atmosphere; that water 
promotes these reductions in a very remarkable manner ; and that 
these reductions of the metals are accompanied by a variety of 
colours, resembling those which frequently mark the surfaces of the 
splendid natural sulphurets, or pyrites. 
A series of experiments, ascertaining the effects of hydrogen and 
sulphuretted hydrogen on various solutions of the different metals, 
aided by the deoxydating powers of carbon, alkalies, and earths, 
would, it seems reasonable to expect, manifest, in the hands of the 
able chemist, that the formation of the brilliant, crystallized, metallic 
pyrites, has depended on, aqueous solution. But the vast mass of 
materials, the great quantity, as well as the density of the super- 
incumbent strata, which must necessarily prevent any escape of the 
• An Essay on Combustion, p. 36 . 
