212 Mr. Majjfey on Saltpetre. 
coarfe powder, and having fcreened it, proceed' 
as follows. 
t They provide a number of finall open tubs, 
which they prefer to large ones, upon account 
of their being more eafily moved, and emptied 
of the materials. Thefe they place upon {tillages, 
about two feet high, and in fuch a manner that 
One veffel may receive the ley, that runs from 
two of them. In each tub, near the bottom, is 
fixt a fpiggot and faufet, and, to prevent the 
wood-afhes from choaking up the latter, a 
parcel of the round earth is thrown in firfi, 
and the allies upon it. They then add the re¬ 
mainder of the earth in the proportion of two 
bufliels of the latter to one of the former. They 
throw the earth in lightly, that the water may 
more readily pafs throught it, and they hollow 
it at the top, that it may more conveniently 
receive it. 
They have different numbers of thefe tubs, 
but generally twenty four, which they place in 
three rows, eight in each; and into each tub 
they throw three bufliels of wood-afhes, and 
fix of earth. Ten demiqueus* of water being 
pafied through the firfi row of eight tubs, is 
poured upon the fecond, and afterwards upon 
the third ; and now the firfi row of eight tubs 
being emptied of the earth and afhes, is re- 
* A demiqueu, as far as we can learn, contains about ninety 
gallons. 
plenifned 
