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¬