MANUFACTURE OF ACETATE OF LEAD. 
261 
The following process wilh metallic lead, recommended first by 
Berard, is easily executed, and it is said by Runge to yield a good 
product with great economy. Granulated lead, the tailings in the 
white lead manufacture, &c, are put in several vessels (say eight) 
one above the other, on steps, so that the liquid may be run from 
one to the other. The upper one is filled with acetic acid, and 
after half-an-hour let off into the second, after another half-hour 
into the third, &c, and so on to the last or eighth vessel. The acid 
causes the lead to absorb oxygen rapidly from the air, evolving 
heat, so that when the acid runs ofFfrom the lowest it is thrown on 
the upper vessel for the second time, it forms a certain quantity of 
acetate of lead in solution, and after passing through the whole 
series is so strong that it may be evaporated at once [to crystallize. 
There are two points of importance in this manufacture ; whatever 
method may be pursued, they are to employ a strong acid, that 
less time and acid may be lost in concentrating the liquid, and to 
keep the solution always acid, to prevent the formation of a basic 
salt. 
It may not be amiss to call attention here to a process patented 
about ten years since for preparing acetate of lead and other ace- 
tates. This process consists in employing the acid in a state of 
vapor, to act upon the bases, instead of using it in the liquid form. 
A vessel is provided of adequate capacity for the quantity of acetate 
required, and constructed of such material as will not be readily 
destroyed by the acid. The top of this vessel is closed hermeti- 
cally by a cover, fastened down by any convenient means, and in 
the lower part of the vessel is placed either a minutely perforated 
false bottom, or a coiled tube of several convolutions, minutely 
perforated, to permit vapor to pass through freely. To prevent 
the loss of acid, there is also placed, at different degrees of eleva- 
tion, several perforated diaphragms, similar to the false bottom 
just mentioned, on each of which is spread a layer of litharge, after 
which the cover of the vessel is to be accurately closed. By means 
of an ordinary distillatory apparatus, liquid acetic acid (strong or 
weak, pure or impure) is converted into vapor, which vapor is 
conducted by means of a pipe into the convoluted perforated pipe 
before mentioned, or between the real bottom of the vessel and the 
perforated false bottom ; hence the vapor passing through the nu- 
merous perforations of the false bottom and diaphragms, diffuses it- 
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