PHYSICAL anv LITERARY. gt 
at the bottom, which .were probably filver. 
Thus the very {mall addition of Spiritus nitri 
very much increafed the folvent power of the 
| fpiritus falis marini. It is known, that ole- 
um vitrioli poured on quick-filver, and kept 
Pie. ae 
in the common air, or in a very gentle heat, 
does not corrode or diffolve it; but, if they 
are brought to a heat exceeding that of boil- 
ing water, then the folution takes place. Mr 
Boyle teftifies, that, by his. care to rectify or 
_ dephlegmate agua fortis very much, he ren- 
dered it unfit to diffolve filver. While agua 
, fortis is diflolving copper with a brifk motion, 
if a little akobol is poured in, the {olution 
: will be ftopt. 
; 
| 
se —— 
VY. Some bodies which we know can be 
_ eafily diffolved in certain liquors, may be fo 
_ changed by the fire, or otherways, that the 
- fame liquors will not afterwards diffolve 
’ them. On the other hand, the fire renders 
_fome bodies fit to be diffolved in certain li- 
 quors which could not be diffolved in them 
er: 
Tue oil of vitriol, as I faid before, affift- 
4 ‘el by a proper degree of heat, readily e- 
~ pough diffolves quick-filver: but when quick- 
~ filver is, by long digattion | in a moderate heat, 
deprived 
