130
Book II.
Division II.
None of
them gase
ous
Or combus
tible.
REMARKS ON THE
bodies which are exposed to its influence. Potass is, if
possible, still more corrosive ; even the hardest mine
ral is unable to resist its action. But sulphat of potass,
though composed of these two formidable bodies, is not
more active than sulphur itself. This singular corre
spondence between simple substances and secondary
compounds, and the striking contrast between them
and the primary compounds, deserve attention. It de
monstrates to us, that the activity of bodies is not pro
portional to their simplicity, as has been hitherto sup
posed ; and that there is some other cause besides com
bination with other bodies to blunt their energy.
Several of the simple bodies exist commonly in the
state of gas: this is the case also with the primary
compounds ; but no gaseous body is found among the
secondary compounds, and only a comparatively small
number of liquid bodies. Almost all of them are so
lid, and probably every one of them is susceptible of
assuming that form. Hence we see that gaseous bo
dies have all of them a considerable degree of simplici
ty; none of them, as far as is known, containing more
than two component parts, if we omit the consideration
of caloric and light altogether ; or three component
parts, if we include these bodies.
None of the secondary compounds are, properly
speaking, combustible. The soaps, indeed, and the ve
getable-acid salts, are susceptible of undergoing a kind
of combustion, but not till they have been previously
decomposed by heat; and even then their combustion is
not to be compared to that of some of the simple sub
stances and primary compounds. Two genera of salts,
namely, the nitrats and oxy-muriats, are supporters of
combustion in a remarkable degree, occasioning violent
detonations when triturated or heated along with com¬