16 
Original Communications. 
nitric acid, which dissolved the yellow colour, leaving a 
white powder unacted on. The acid solution gave a deep 
blue colour when tested with ferrocyanate of potassa. The 
white powder unacted on by the acid, was mixed with char- 
coal and heated before a blowpipe; vapours of sulphuric 
acid were given off, and small globules of metallic lead 
formed. These crystals are therefore sulphate of lead, co- 
loured by adhering oxide of iron. If their weight (five parts) 
be added to the sulphate of lead, separated by the filter, it 
will give 633 parts as the whole of this salt formed. 
Another mode of procuring the salt is by decomposing 
acetate of lead in solution by metallic zinc. Lead precipi- 
tates in crystals, and the zinc uniting with acetic acid and 
oxygen, occupies its place in solution. The equivalent pro- 
portions are, one equivalent of zinc 34, and one equivalent of 
acetate of lead 190. If 8 ounces of acetate of lead are used, 
the quantity of zinc required, according to theory, would be 
1 ounce, 3 drams, 27 grains. 
The stronger the solution of acetate of lead, the more ra- 
pid, of course, would be its action on the zinc. Acetate of 
lead dissolves in about four times its weight of water to form 
a saturated solution. This would then be the proper propor- 
tion of water. 
In order to ascertain the most eligible proportions of the 
acetate of lead and of zinc, the following experiments were 
made, the temperature in each instance being the same, 
above 60°; 
1st. Acetate of lead 800 parts, 
Mossy* zinc 400 parts, 
Distilled water 3200 parts. 
After standing a week, the liquid still showed traces of lead 
when tested with sulphuretted hydrogen. 
2d. Acetate of lead 800 parts, 
Granulated zinc 200 parts, 
Distilled water 3200 parts. 
Four or five days were required for the complete decompo- 
sition of the acetate of lead. 
* Made by pouring melted zinc into water. 
