( po ) 
Nature. And becaiife Chymiiliy is an Art of joyning' 
Bodies that are feparated, or leparating fuch as are 
joyned, he divides the Operations of Chymiiliy into 
two forts s 'viz,. Inch as difunite the Parts of bodies 
from one another, and llich as compound or mix them 
together. The Chymills not agreeing what are, to be" 
put in tl!C fecond Clafs and wh-at in the lirll, Jie folfows 
a new Order, and among the lirll Clals he reckons Cd- 
Sublimanpri 2.nd DifiilUt;ion\ in the fecond are 
ran lied Fermentation^ Digejtwhy Exiradion^ Precipitation 
a nd Crjftahization. 
His defign in this Treatife is to explain firB, The Me- 
thod of each Operation according to this Order,and the • 
Mechanical force by which it is produced. Secondly, 
7 he different n ays by which it commonly is, or may be 
performed ; And Thirdly, He gives us many particular 
Experiments, which he explains and reduces to the Ge- 
neral Theory laid down at hrll. Accordingly we have 
here the reafon of the Cohefion of Bodies, which he 
draws from the Principle of Attradlion, and the quan- 
tity of Contaff ; the Caufesof Fluidity and Liquation; 
the reafon why lome Bodies, as Wax and Metals, being 
melted in the Fire, and afterwards cooled, do return to 
their Hril Form, whereas others by Fire acquire a new 
one ; How it comes about, that the abfolute weight of 
.Bodies is generally after Calcination encreas’d, and the 
'Specifick Gravity diminifh d. We have alfo the rea- 
fon, why Fluids rife in an Alembick ; and he mows that 
if a Globule of Water be fo rarihed, as to have its Di- 
ameter made only ten times greater, it will become 
lighter than the Air, and confequently muff rife up in it :■ 
But if the Diameter be encrealed in the proportion of 12 
to r, the Bubble of Water becomes more than twice as 
light as our common Air, and muff therefore rife fo 
much the faffer. Bcfides this, the Air itfelf being rarilied 
muff neceifarily rife up, and the force of its motion ear- 
