$16 Of Saifs, 
faffil fait, would flick to it 3 but fait of tin out-does sfi 
for beauty, in which are lines like little needles, that 
f'pread themfelves every where from a point, as from a 
center, fo as to reprefent a ftar, much like what we fee 
In the regains of Mars. 
Salts have this peculiar property, that let them be ever 
fo divided and -reduced into minute particles, yet when 
they are formed into cryftals, they each of them re-ailume 
their proper fhape 3 fo that they may be as eafily divefted 
and deprived of their faltnefs, as of their figure. 'Whence 
By knowing the figure of the cryftals, we may under- 
Hand what the texture of the particles ought to be, which 
can form thefe cryftals. And by knowing the texture of 
the particles, we may determine the figures of the cry- 
fitals. For fmee the figures of the moft fimple parts remain 
always the fame, it is evident the figures which they run 
Into, when compounded and united, mu ft be uniform and 
eon ft ant. 
Efiential falts are made by exprefling the juice of any 
plant, and fetting it in a cellar to fhoot 3 which fome do 
in fmall quantities. 
Fixed falts are made as follows : 
Take any plant, and bum it on a clean hearth, and 
rake the afhes as long as any fire appears among them ; 
put thofe allies into an unglazed pan, which fet in a cal¬ 
cining furnace, make fire about it till the pan is red-hot j 
where keep it, continually ftirring the afhes without any 
blacknefs. Then put them into a clean pan, and pour 
hot water upon them 3 when that water is fuiftdently 
impregnated with fait, filter it, and evaporate to a drynefs, 
until the afhes are left infipid. 
The falts of metals or minerals are to be come at by 
quenching them, when red hot, in water, then filtering, 
evaporating, and cryftallizing. 
if 
