The oil of pine-apples is obtained from a
product of the action of putrid cheese on
sugar, or by making a soap with butter, and
distilling it with alcohol and sulphuric acid ;
and is now largely employed in England in
making pine-apple ale. Oil of grapes and oil
of cognac, used to impart the flavour of French
cognac to British brandy, are little else than
fusel oil. The artificial oil of bitter almonds,
now so largely employed in perfuming soap
and for flavouring confectionary, is prepared
by the action of nitric acid on the fœtid oils of
gas-tar. Many a fair forehead is damped
with eau de millefleurs, without knowing that
its essential ingredient is derived from the
drainage of cowhouses. In all such cases as
these, the chemical science involved is, really,
of a high order, and the perfume produced is
a bona-fide perfume, not one whit less sterling
than if produced from fruits and flowers.
The only question is one of commercial
honesty, in giving a name no longer applicable,
and charging too highly for a cheaply
produced scent. This mode of saving a penny
is chemically right, but commercially wrong.

The French make a large quantity of sugar
from beet-root; and in the processes of
manufacture there remains behind a thick, black,
unctuous molasses, containing much sugar,
but from other causes impregnated with a
nauseous taste and a most disagreeable smell.
Men will not eat it, but pigs will; and so to
the pigs it has gone, until M. Dubranfaut
showed (as he has lately done), that this
molasses is something better than pig's meat.
He dissolves, and decomposes, and washes,
and clarifies, until he ends by producing a
kind of eau sucré, a beautifully clear and
colourless syrup or sugar-liquid, containing
nearly the whole of the saccharine principle
from the offensive and almost valueless
molasses.

How can we make one kind of paint or
liquid produce many different colours, and
this with an amount of material almost
beneath the power of man to weigh or measure?
Mr. De la Rue has solved this question by
the production of his beautiful iridescent and
opalescent paper. Both mechanically and
optically, the production of these papers is
strikingly interesting. Water is poured into
a flat vessel; and, when quite tranquil, a very
minute quantity of spirit varnish is sprinkled
upon the surface: this, by a species of
attraction between the two liquids, spreads
out on all sides, and covers the whole surface
in a film of exquisite thinness. A sheet of
paper, or a card-board, or any other article, is
then dipped fairly into the water, and raised
gently with that surface uppermost which is
to receive the coloured adornment ; it lifts
up the film of varnish from off the surface of
the water, and this film becomes deposited on
the paper itself. The paper is held in an
inclined position, to allow the water to drain
off from beneath the film ; and the varnish
then remains permanent on the surface of the
paper. Now, the paper thus coated with
colourless varnish exhibits the prismatic
tints with exquisite clearness ; the film of
varnish is so extremely thin—so far beneath
anything that could be laid on with a
brush or pencil—that it reflects light on the
same principle as the soap-bubble, exhibiting
differences of colour on account of minute
differences in the thickness of the film at
different parts ; and not only so, but the
self-same spot exhibits different tints according
to the angle at which we view it. It is a
lovely material, and lovely things may be
produced from it. We cannot speak of it as
producing something out of nothing; but it
is a means of producing a beautiful result with
a marvellously small expenditure of
materials.

The clinkers, ashes, or cinders, which
remain in furnaces after metallurgic operations
have been completed, may appear to
be among the most useless of all useless
things. Not so, however. If they contain
any metal, there are men who will ferret it
out by some means or other. Not many
years since, the ashes of the coke used in
brass-furnaces were carted away as rubbish;
but shrewd people have detected a good deal
of volatilised copper mixed up therewith;
and the brass-makers can now find a market
for their ashes as an inferior kind of copper
ore. It needs hardly to be stated that all
sorts of filings and raspings, cuttings and
clippings, borings and turnings, and odds and
ends in the real metallic form, are all available
for re-melting, whatever the metal may be—
all is grist that comes to this mill. If the
metal be a cheap one, it will not pay to extricate
a stray per centage from ashes and
clinkers; but, if it be one of the more costly
metals, not only are all scraps and ashes and
skimmings preserved, but particles are sought
for in a way that may well astonish those to
whom the subject is new. Take gold as an
example. There are Jew dealers and Christian
dealers also, who sedulously wait upon gilders
and jewellers at intervals, to buy up everything
(be it what it may) which has gold in
or upon it. Old and useless gilt frames are
bought; they are burnt, and the ashes so
treated as to yield up all their gold. The
fragments, and dust of gold, which arise during
gilding, are bought and refined. The leather
cushion which the gilder uses is bought when
too old for use, for the sake of the gold
particles which insinuate themselves into odd
nooks and corners. The old leather apron of
a jeweller is bought ; it is a rich prize, for in
spite of its dirty look, it possesses very
auriferous attractions. The sweepings of the
floor of a jeweller's workshop are bought ;
and there is probably no broom, the use of
which is stipulated for with more strictness
than that with which such a floor is swept.
In short, there are in this world (and at no
time so much as the present) a set of very
useful people, who may be designated