328 ESSAYS ano OBSERVATIONS © 
rit was originally produced. Confequently 
there appears to be fome affinity betwixt the 
native fixt bafes of thefe falts, and the fixt 
falts of plants. 
VI. Tue artificial vitriols compounded of 
the fame acid fpirits and metallic particles, | 
do not refemble the original falts; but the 
vitriols of different metals, or metallic bo- 
dies, have different fhapes, tho’ they are join- 
ed to the fame acid falts. 
VII. Tue acid falts, tho’ combined with 
the alcaline, into mild neutral falts, yet are 
not fo changed by this union but, when they 
are again artfully disjoined, they may exert 
the fame powers and produce the fame ef- 
fects as before their union: therefore we may 
conclude, that the figure, bulk, and denfity 
of the acid particles are not changed, tho’ 
the liquors may differ fomewhat in ftrength 
from the greater or fmaller proportion of 
phlegm, or water accompanying the real a- 
cid. 
VII. One acid which has been united to 
an alcaline falt may be fet at liberty, or ex- 
pelled from its cohefion with the alcaline 
falt, by another acid of a different origin. 
But this does not happen indifcriminately; — 
for = 
