on the fluoric Compounds, 73 
hitherto escaped detection, but which may be expelled, or 
newly combined, during its combustion in oxygen. That 
some chemical difference must exist between the hardest and 
most beautiful of the gems and charcoal, between a non-con- 
ductor and a conductor of electricity, it is scarcely possible, 
notwithstanding the elaborate experiments that have been 
made on the subject, to doubt: and it seems reasonable to 
expect, that a very refined or perfect chemistry will confirm 
the analogies of nature, and shew that bodies cannot be ex- 
actly the same in composition or chemical nature, and yet 
totally different in all their physical properties. 
MDCCCXIV. 
L 
