f any essential oil are sufficient also to
keep books entirely free from it. For harness, oil of turpentine is
recommended. Bookbinders, in general, employ alum for preserving their
paste; but mould frequently forms on it. Shoemakers' resin is sometimes
also used for the same purpose; but it is less effectual than oil of
turpentine. The best preventives, however, are the essential oils, even
in small quantity, as those of peppermint, anise, or cassia, by which
paste may be kept almost any length of time; indeed, it has, in this
way, been preserved for years. The paste recommended by Dr. Macculloch
is made in the usual way, with flour, some brown sugar, and a little
corrosive sublimate; the sugar keeping it flexible when dry, and the
sublimate preventing it from fermenting, and from being attacked by
insects. After it is made, a few drops of any of the essential oils are
added. Paste made in this way dries when exposed to the air, and may be
used merely by wetting it. If required to be kept always ready for use,
it ought to be put into covered pots. Seeds may also be preserved by
the essential oils; and this is of great consequence, when they are to
be sent to a distance. Of course moisture must be excluded as much as
possible, as the oils or ottos prevent only the bad effects of mould.

* * * * *

FUSEL OIL.

BY W. BASTICK.

This organic compound was first discovered by Scheele, as one of the
distillation products of the wort obtained from the fermentation of
potatoes. It has been subsequently examined by Pelletier, Dumas,
Cahours, and others. It is generally now termed the hydrate of the oxide
of amyl, from amyl being supposed to be its base or radical, as cyanogen
is regarded to be the radical of another series of compounds.

It passes over towards the termination of the distillation process in a
white turbid fluid, which consists of a watery and alcoholic solution of
the fusel oil. The crude oil, consisting of about one-half of its weight
of alcohol and water, may be purified, being shaken with water and
redistilled, with the previous addition of chloride of calcium. When the
temperature of the contents of retort reaches 296 deg. Fahr., pure fusel oil
distils over.

Fusel oil is a colorless oily fluid, which possesses at first not an
unagreeable odor, but at last is very disgusting, producing oppression
at the chest and exciting cough. It has a sharp hot taste, and burns
with a