308 ESSAYS ann OBSERVATIONS 
Unper the head of folution, I had occa- 
fion to adduce a well known inftance, to 
fhow that a menfiruum having diflolved one 
body, will fucceffively diffolve feveral others 
in a certain order. , d_am obliged to mention — 
the fame again, as a confirmation of the pre- 
fent remark. If pure filver is diffolved in 
proof aqua fortis, and the folution diluted 
with fair water; the filver will be precipitated 
by copper, the diffolved copper by iron, and 
that by lime-ftone. This however is not the 
fole inftance of this way of precipitation: o- 
thers may be found. The fublimate corro- 
five mercury may be, juftly looked upon asa 
folution of quick-filver ip the acid of fea 
falt or agua regia, brought into a chryftalline 
or vitriolic form by fublimation: when this 
corrofive mercury is mixed with an equal 
weight of common antimony, and thefe 
rubbed together, left to moiften in the air, 
- and then diftilled ; there happen fuch changes 
to this mixture, as evidently fhow a real pre- 
cipitation of the quick-filver by the reguline 
part of the antimony; for the acid forfakes 
the quick-filver, and diffolves the regulus, 
which makes the butyrum antimonii ; and the 
quick-filver freed from the acid, is by the fire 
incorporated 
