with another one by electrolysis. The voltameters in which this second
operation is performed have likewise been modified. They consist now
(Fig. 2) of cylindrical glass vessels, AH, 125 mm. in diameter by 600 in
height, with polished edges. These are hermetically closed by an ebonite
cover through which pass the tubes, B' C' and B C, that allow the
liquid, E+E-E'+E', to circulate.

The current of spirits is regulated at the entrance by the cock, R,
which, through its division plate, gives the exact discharge per hour.
In addition, in order to secure great regularity in the flow, there is
placed between the voltameters and the reservoir that supplies them a
second and constant level reservoir regulated by an automatic cock.

In practice, Mr. Naudin employs 12 voltameters that discharge 12
hectoliters per hour, for a distillery that handles 300 hectoliters of
impure spirits every 24 hours. The electric current is furnished to the
voltameters by a Siemens machine (Fig. 3) having inductors in
derivation, the intensity being regulated by the aid of resistance wires
interposed in the circuit of the inductors.

The current is made to pass into the series of voltameters by means of a
commutator, and its intensity is shown by a Deprez galvanometer. The
voltameters, as shown in the diagram, are mounted in derivation in
groups of two in tension. The spirits traverse them in two parallel
currents. The Siemens machine is of the type SD2, and revolves at the
rate of 1,200 times per minute, absorbing a motive power of four horses.

[Illustration: FIG. 3.--ARRANGEMENT OF THE SIEMENS MACHINE.]

The disacidification, before entering the rectifier, is effected by the