Lead . 
255 
scalds, and bruises. It is this last only, which is the che= 
mica! test of the presence of mucilage and gum : where- 
on see Dr. Bostock’s paper in 11 Nicholson’s Journal, p. 
75. This saturated salt of lead, Goulard’s extract, or 
the aqua lythargyri acetati, contains lead 21, acetite acid 
5, oxygen 2,1, water 71,9 : whereas the sugar of lead or 
acetite of lead of commerce contains in 100 parts, lead 
15,3, acetite acid 7 , 5 , oxygen 1,5, water 75,7. 
Take the corroded lead scraped off the blue lead in the 
manufacture of white lead : dissolve this in strong, clear, 
Well- fined, colourless vinegar. If it be not so, it must 
be made so by distillation. A moderate heat will assist 
the solution ; but if heat be applied, it should be in close 
vessels. The vessels should be of glass or earthen ware ; 
(or perhaps tin might answer). The vinegar should not 
be quite saturated. The solution should slightly redden 
litmus paper. Draw off the solution quite clear. Crys- 
tallize by slow evaporation. If the crystals be not per- 
fect, dissolve the crystallized mass over again in distilled 
vinegar, which I believe the Dutch always use. 
I fancy the first washings of the white lead in the white 
lead manufactory, may be worth saving and evaporating, 
where the intent is to make sugar of lead. 
This I believe to be the process : but I am not confi- 
dent of the accuracy of my information. In ray time it 
was not made in England : it was entirely imported from 
Holland. The calico printers used it in very large quali- 
ties to make printers mordant, the acetite of alumine. 
This is made by mixing from one part to one part and a 
half of sugar of lead in saturated solution, with a saturat- 
ed solution of one part of ground alum. The alum must 
be previously tried to see whether it contain iron: if it 
do, it will turn the madder red of a chocolate hue. 
I have already suggested, that the acetite of lime, made 
