[ rx; ] 
through brown Paper, fupported by a coarfe Cloth, 
fixed to the Four Corners of the filtring Frame. 
When the whole Mafs of the Lye and of the Lime 
is well drained, I put it into an iron Pot that is very 
clean, with Ten Quarts of Water, to the Quantity 
taken. out of each Pan, and let it boil an Hour 5 then 
I filtrate it a fccond time. Afterwards it is put into 
another iron Pot that is very clean, and as it evapo- 
rates by Degrees, it is filled up again with the firft Lye 
prepared, without boiling. I let it continue to 
evaporate till the Twenty-eight Quarts of Water, 
that have been ufed for making the Lye of the Mix- 
ture that was at firft put into each of the Pans, be 
reduced to Two Quarts and half a Pint, or fo long till 
a fmall falmous Film forms itfelf on the Top of 
the Lye. This Liquor turns almoft black, becaufe 
it corrodes the Iron 5 but this is no Inconvenience, as 
will appear hereafter. In this State of Concentration, 
if one lets a Drop of it, whilft it is hot, fall on a Piece 
of Glafs, it will be very quickly covered with a fine 
and greafy Film, which makes it look as if it was 
congealed. At the Bottom of this Lye is found a 
Salt in Flakes, which, being melted in a Crucible, 
produces a Lapis inf emails of a ftrong cauftic Power. 
One may know alfo, that the Lye has acquired the 
necefiary Degree of Concentration, when, becoming 
more a&ive, one fees, that the Edge of the Pot that 
has been wetted by it, turns red, whilft the lower 
Part of the Side all around, down to the Surface of 
the Liquor, takes a greenilh Colour. Then the Pot 
muft be taken from the Fire, and the Liquor left to 
cool fo far as to be put into Glafs Bottles without 
cracking them : The Bottles ought to be carefully 
corked. 
