213 
Mr. MaJJey on Saltpetre. 
plenifhed with frefh materials, and the ley, 
which has pafled through the three rows of 
eight tubs, is pafled through this likewife. 
Having thus palled through four rows of eight 
tubs, and been reduced to two demiqueus by 
the abforption of the materials, it is carried to 
the boiler under the name of le Cuite. 
Such is the procefs when a new work is 
erected j in an old one, only fix demiqueus of 
water are paffed through the three rows of eight 
tubs, which are filled with frefh materials every 
day, 
The lixivium is carefully fcummed, during 
the boiling, and, when it is fo far advanced, that 
a peliicle begins to appear upon the furface, a 
workman is conftantly employed, withaperforated 
ladle, to take out the marine fait, which now 
begins to form and fall to the bottom of the 
boiler. This being thrown into a whifket, drains 
into the boiler again. When the lixivium is fo 
far evaporated, that a drop of it will congeal 
upon a piece of cold iron, it is taken out, 
and thrown into a tub, fcr the remainder of 
the marine fait, and other dregs, to fettle; 
2nd, after handing about half an hour, it is 
drawn off, whilft yet warm, into fhallovv copper 
pans, and fet in a cool place for the faltpetre 
to cryftallize. 
The produce of this operation is generally 
about one hundred and thirty pounds of a brown 
P 3 fort, 
