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into a Copper, with as much common Water as is fuf" 
ficient to diffolve them, and allow of a gentle Evapo- 
ration, till fuch Time as they are again ready to be 
pour’d into the Coolers in order for Cryftalization. 
This generally proves to be the pure Sal Catharticum, 
throughly freed (as far as the Experiments I have try’d 
can be convincive) from either a Sea Salt, or the third 
Salt. The Liquor decanted from this Shooting, may 
be. boil’d down again ’in order for a fecond Shooting, 
and after that a third *, but as the Liquors from thefe 
Shootings are boyl’d away more or lefs, fo you will 
fooner or later meet again with the pungent Liquor, 
which contains the third Salt, as you did in the former 
Shootings ' froiti ( the Bittern, which the pure Sal Ca- 
tharticum is as hecelfarily- required to be freed from, 
as froip the common Salt, a Proof of which cannot 
be better determined than by one of the Experiments 
to be taken Notice of hereafter (viss.) that with the 01. 
Vitriol, which will certainly ferment with this Salt, if 
the Sea Salt has not been well feparated from it, or if it 
Hill holds fome of the third Salt. And when any of 
the Cryftalizations will not hand the Teft of this Ex- 
periment, they ought to be dilfolv’d and fhot again-, as 
before, by which means the pure Salt is to be obtain’d. 
I do not mention this as a Tryal made ufe of at the 
Salt-Works, but what I have by Experience found to 
be true. And the fame Experiment will ferve to diftin- 
guilh a Sal Mirabile made at thefe Works, from that 
made with 01. VitrioU and common Salt. The Account 
they give of it is this.. They take any Qiaantity of 
coarfer grain’d Cryftals boyl’d from the Bittern, which 
when dilfolv’d and evaporated, more than they would 
otherwife do for making the Sal Catharticum, they 
throw into a wooden Bowl, with forne Oil of Vitriol, 
where it hands for ten Days, and Ihoots into large 
Cryftals, 
