On Acetate of Zinc. 
15 
The quantity of acetate of zinc yielded ought to be to the 
sulphate employed in the proportion of 156 to 145, which 
gives for the 6 oz., 6 oz. 3 dr. 38.48 grs. 
While evaporating a solution of acetate of zinc obtained 
according to the above process, at a boiling heat, a conside- 
rable quantity of a white powder was found to precipitate. 
This powder when heated before a blow pipe assumed a yel- 
low colour, which it lost on cooling. It dissolved in acids with- 
out effervescence and without giving off any odour of acetic 
acid, and the solution gave a white precipitate with hydrosul- 
phate of ammonia and with the alkalies. The caustic alka- 
lies when in excess redissolved the precipitate. The alkaline 
carbonates gave precipitates which were insoluble in an ex- 
cess of the precipitant. When its solution in dilute sulphuric 
acid was evaporated, small crystals formed, which were 
four sided prisms, having all the properties of sulphate of 
zinc. The powder then was simply oxide of zinc, from which 
the acetic acid had been driven off by the too great heat em- 
ployed in evaporating. The solution ought therefore to be 
evaporated- with a moderate heat; when it becomes concen- 
trated a water bath should be employed. A boiling heat does 
not decompose the salt when the solution is weak. 
The quantity of water directed for dissolving the sulphate 
of zinc and acetate of lead appearing larger than necessary, 
in order to shorten the subsequent evaporation one half was 
used, and acetate of zinc prepared (with this exception) ac- 
cording to the proportions directed in the Pharmacopoeia, as 
follows : 
Sulphate of zinc, 600 parts, 
Acetate of lead, 800 parts, 
Distilled water, 6400 parts. 
The salts were dissolved separately in the water, and the 
solutions mixed. Six hundred and twenty-eight parts of sul- 
phate of lead (when dried) were separated by a filter ; six 
hundred and forty-two parts of crystallized acetate of zinc 
were obtained after evaporation. During the evaporation, 
minute yellow crystalline grains formed in the liquid. These 
small crystals were separated by a filter, and treated with 
