On Acetate of Zinc. 
17 
3d. Acetate of lead 800 parts, 
Mossy zinc 600 parts, 
Distilled water 3200 parts. 
About twelve hours required. 
4th. Acetate of lead 800 parts, 
Granulated zinc 300 parts, 
Distilled water 3200 parts. 
About eight hours required. 
5th. Acetate of lead 800 parts, 
Mossy zinc 800 parts, 
Distilled water 3200 parts. 
In six hours no trace discoverable. 
6th. Acetate of lead ' 800 parts, 
Granulated zinc 400 parts, 
Distilled water 3200 parts, 
In six hours no trace discoverable. 
In all these experiments, a larger proportion of zinc is em- 
ployed than that indicated by the atomic weights. Less 
would no doubt answer, but the time required in the process 
would be proportionally increased. Granulated zinc acts 
with rather greater rapidity than twice its weight of mossy 
zinc. Although a greater quantity is required, it is best to 
use mossy zinc, as it is much more easily made, and is less 
apt to contain impurities than the granulated. It will be 
generally most convenient to use a large proportion of zinc, 
in order that it may not require much time to decompose the 
acetate of lead. The proportions probably preferable are 
those used in Experiment 5 ; or if given in definite quantities 
as follows : 
Acetate of lead 8 oz. 
Mossy zinc 8 oz. 
Distilled water 2 pints.* 
Dissolve the acetate of lead in the water, and add the zinc ; 
allow it to stand until the solution gives a pure white precipi- 
tate when tested with sulphuretted hydrogen ; then pour off 
* This quantity of water, though it is rather less than four times the weight 
of the acetate of lead, is sufficient to dissolve it. 
Vol. I— No. 1 3 
