a a ne Ol hue eee ee 
PHYSICAL ano LITERARY. 293 
til'the ores are roafted, 'wafhed and finelted. : 
The calces of lead and tin will more eafily 
diffolve in) fpirit of vinegar, than the thin 
plates or fhavings of the fame metals. 
- VI. Some liquors which diffolve feveral 
different bodies,’ while they perform the fo- 
lutions, feem to act in a different manner up- 
on each body, require different helps, and 
diffolve different quantities each. 
_ Yuisis very remarkable in the ation of 
oil of vitriol upon iron and quick-filver : to 
make oil of vitriol diffolve iron fuccefsfully, 
it muft be diluted with a quadruple quantity 
of water; when the cleaa fileings are put in- 
to this liquor by degrees, there arifes a {trong 
ebullition and effervefcence, with a confider- 
able heat and thick fteams of a penetrating ful- ’ 
_ phurous {mell, which are apt to kindle and 
make a fulminating yoife upon the approach 
of the flame of a candle; and, laftly, one 7 
ounce of oil of vitriol thus diluted will diffolve 
an equal weight of pure fileings of fteel: but, 
when oil of vitriol is employed to diffolve 
guick-filver, it muft be flrong and well de- 
phlegmated : when it is poured upon the 
 guick-filver, it raifes no inteftine motion or 
heat ; it does not begin to corrode or diflolve 
’ me the 
