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
metallic zinc. Let us now examine what economic advantages this process
presents over the old method of rectifying by pure and simple
distillation. The following are the data given by Mr. Naudin:

In ordinary processes (1) a given quantity of impure alcohol must
undergo five rectifications in order that the products composing the
mixture (pure alcohol, oils, etc.) may be separated and sold according
to their respective quality; (2) the mean yield in the first
distillation does not exceed 60 cent.; (3) the loss experienced in
distillation amounts, for each rectification, to 4 per cent.; (4) the
quantity of essential oils (mixture of the homologues of ethylic
alcohol) collected at the end of the first distillation equals, on an
average, 3.5 per cent.; (5) the cost of a rectification may be estimated
at, on an average, 4 francs per hectoliter.

All things being equal, the yield in the first operation by the electric
method is 80 per cent., and the treatment costs, on an average, 0.40
franc per hectoliter. The economy that is realized is therefore
considerable. For an establishment in which 150 hectoliters of 100 deg.
alcohol are treated per day this saving becomes evident, amounting, as
it does, to 373 francs.

We may add that the electric process permits of rectifying spirits
which, up to the present, could not be rectified by the ordinary
processes. Mr. Naudin's experiments have shown, for example, that
artichoke spirits, which could not be utilized by the old processes,
give through hydrogenation an alcohol equal to that derived from Indian
corn.--_La Nature_.

* * * * *

PLASTIC CARBON FOR BATTERIES.

Max Nitsche-Niesky recommends the following in _Neueste Erfindung_.:
Good coke is ground and mixed with coal-tar to a stiff dough and pressed
into moulds made of iron and brass. After drying for a few days in a
closed place, it is heated in a furnace where it is protected from the
direct flames and burned, feebly at first, then strongly, the fire being
gradually raised to white heat which is maintained for 6 or 8 hours