332 ESSAYS arp OBSERVATIONS © 
part, which attracts, or is attracted by the 
phlegm or watry part of the mixture, is ea- 
fily raifed up in vapour by heat, and turned 
into a faline acid liquor. 
Ir may be juftly queftioned, whether this 
is an ultimate divifion of nitre, or a feparation 
of it into its moft fimple principles or firft e- 
lements. It is very hard to find an experi- 
ment that can give full fatisfaction in this 
point; for there are’ certain bounds fet to 
art, as to the divifion of bodies: but if that 
part of nitre, which unites with the acid 
of vitriol into a-neutral falt, is the fame with 
nitre fixt by deflagrating with char-coal; or 
if it is no other than that falt which can be 
extracted from the remains of the diftillation 
of nitre with bole; then we have fome rea- 
fon to conclude, that this part of nitre is not 
a fimple elementary matter: fince fixt/nitre 
can, by frequent folutions and fufions, be fo) 
changed, that little of it will remain, but a 
mere earth. 
Many of the folutions which happen in 
chemiftry, are of the firft kind, that is, the 
folvents aét no otherways upon their proper 
objects than water does upon nitre or any o- 
ther falt, by diffolving the cohefion of the 
larger 
