I 
Green Vitriol, or Englijh Copperas ; j|j% 
of a ponderous and compad Subfiance, con» 
tain Metal and Sulphur, have a rufly fer¬ 
ruginous Outfide, but internally appeal 
when broken, fometimes of the Colour of 
Brafs, Silvery fometimes, and fometimes like 
Iron; the Matter compofing them is dif- 
pofed in Striae, or a linear Dirdlon di¬ 
verging from a central Point to the Cir¬ 
cumference, if the Stones have any thing 
of a circular or cylindric Figure; or lying 
parallel and perpendicular to the fiat Sides, 
if their Form be flattifh. After being 
long expofed in Heaps to. the Air and 
Rain, the Salts begin to ad, vitriolic Ef- 
forefcences pufh out upon the Surface, 
they become brittle, fall to Pieces, and 
diffolve into a Liquor. This Liquor, when 
boiled two or three Days in a leaden Caul¬ 
dron, (Pieces of Iron being thrown in from 
Time to Time during the boiling and dif- 
folving in the faid Liquor) is difpofed af¬ 
terwards in convenient Veffels, where it 
Hands for about a Fortnight to cryflalize 
into Vitriol. A great Work of this Kind 
is, or was not long ago, carried on at 
Deptford\ 
O 4 C H A P. 
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