ainst excessive
cold. Great care should be taken that a thorough ventilation be given
in the first mentioned type. In the other, more substantial silos,
ventilation must be watched, and all communication with the exterior
closed as soon as the temperature falls to or near freezing.

During the last campaign many manufacturers experienced great
difficulty in keeping the blades of slicers sufficiently sharp to work
frozen beets. Sharpening of blades is an operation attended to by
special hands at the factory; and under ordinary circumstances there
need be no difficulty. However, it is now proposed to have central
stations that will make a specialty of blade sharpening. Under these
circumstances manufacturers located in certain districts need give the
matter no further thought, let the coming winter be as severe as it
may.

Some success has been obtained by the use of sulphurous acid in vacuum
pans. Great care is required; the operation cannot be done by an
ordinary workman. It is claimed that graining thereby is more rapid
and better than is now possible. Chemists agree that the operation is
more effectual by bringing sulphurous acid in contact with sirups
rather than juices; it is in the sirups that the coloring pigments are
found. Sulphurous acid is run into the pan until the sirups cover the
second coil. In all cases the work must be done at a low temperature.

Height of juice in carbonatating tanks is only three feet in France,
while in Austria it is frequently twelve feet. The question of a
change in existing methods is being discussed; it necessitates an
increase in the blowing capacity of machine; since carbonic acid gas
has a greater resistance to overcome in Austrian than in French
methods. Longer the period juices are in contact with carbonic acid,
greater will be the effect produced.

Ferric sulphate has been very little used for refuse water
purification, owing to cost of its manufacture. If roasted pyrites, a
waste product of certain chemical factories, are sprinkled with
sulphuric acid of 66 deg. B., and thoroughly mixed for several hours, at a
temperature of 100 deg. to 156 deg. F., the pyrites will soon be covered with
a white substance which is ferric sulphate. Precipitates from ferric
sulphate, unlike calcic compounds, do not subsequently enter into
putrefaction.

Efforts are being made to convince manufacturers of the mistake in
using decanting vats, in connection with first and second
carbonatat