116 
Mr. Majjey on Saltpetre. 
obferving one encouragement which an adven¬ 
turer in this way will always have, viz. that 
whatever materials he may lay together, for this 
purpofe, if they do not anfwer his end, as a falt- 
petre maker, will always find their value with 
the farmer. 
Wood-allies are certainly an article of great 
importance, but (hould they ever be found 
wanting their deficiency may be fupplied, as we 
have hinted above. Thofe who may engage 
in thefe undertakings, with the lead rifque or 
expence, are certainly the pot-alh makers in 
this kingdom, who, being provided with the 
neceflary utenfils, can only want a proper earth 
to begin their operations, which, in cafe they 
are unprovided, we have fiiovvn, may be eafily 
procured in the fpace of a year or two, by mix¬ 
ing up their dunghills with fallen lime, and fuf- 
fering them to lie till they are perfectly pu¬ 
trefied. 
The author, fome years ago, caufed a trench 
to be dug in an open field, ten yards long, one 
yard wide, and one foot deep. This he half filled 
with good muck from a dunghill, and covering 
it up with the foil, mixt with one third the 
quantity of fallen lime, left it to take its fate. 
The weeds were plucked off, as they fprouted up, 
and it was twice turned over in the fpace of a year; 
at the end of which, this earth, being elixivi- 
ated with wood-allies, afforded him fair cryftals 
of 
