Not a member?     Existing members login below:
Holidays Offer
 

The Chemical History of a Candle


possibly give. The fuel provided, the means of bringing that fuel to the place of
chemical action, the regular and gradual supply of air to that place of action—heat
and light—all produced by a little piece of wood of this kind, forming, in fact, a
natural candle.
But we must speak of candles as they are in commerce. Here are a couple of candles
commonly called dips. They are made of lengths of cotton cut off, hung up by a loop,
dipped into melted tallow, taken out again and cooled, then re -dipped until there is
an accumulation of tallow round the cotton. In order that you may have an idea of
the various characters of these candles, you see these which I hold in my hand—
they are very small, and very curious. They are, or were, the candles used by the
miners in coal mines. In olden times the miner had to find his own candles; and it
was supposed that a small candle would not so soon set fire to the fire-damp in the
coal mines as a large one; and for that reason, as well as for economy's sake, he had
candles made of this sort—20, 30, 40, or 60 to the pound. They have been replaced
since then by the steel-mill, and then by the Davy-lamp, and other safety-lamps of
various kinds. I have here a candle that was taken out of the Royal George[1], it is
said, by Colonel Pasley. It has been sunk in the sea for many years, subject to the
action of salt water. It shews you how well candles may be preserved; for though it
is cracked about and broken a good deal, yet, when lighted, it goes on burning
regularly, and the tallow resumes its natural condition as soon as it is fused.
Mr. Field, of Lambeth, has supplied me abundantly with beau tiful illustrations of the
candle and its materials. I shall therefore now refer to them. And, first, there is the
suet—the fat of the ox—Russian tallow, I believe, employed in the manufacture of
these dips, which Gay Lussac, or some one who entrusted him with his knowledge,
converted into that beautiful substance, stearin, which you see lying beside it. A
candle, you know, is not now a greasy thing like an ordinary tallow candle, but a
clean thing, and you may almost scrape off and pulverise the drops whic h fall from it
without soiling anything. This is the process he adopted[2]:—The fat or tallow is
first boiled with quick-lime, and made into a soap, and then the soap is decomposed
by sulphuric acid, which takes away the lime, and leaves the fat re -arranged as
stearic acid, whilst a quantity of glycerin is produced at the same time. Glycerin—
absolutely a sugar, or a substance similar to sugar—comes out of the tallow in this
chemical change. The oil is then pressed out of it; and you see here this series of
pressed cakes, shewing how beautifully the impurities are carried out by the oily
part as the pressure goes on increasing, and at last you have left that substance
which is melted, and cast into candles as here represented. The candle I have in my
hand is a stearin candle, made of stearin from tallow in the way I have told you.
Then here is a sperm candle, which comes from the purified oil of the spermaceti
whale. Here also are yellow bees-wax and refined bees-wax, from which candles are
made. Here, too, is that curious substance called paraffin, and some paraffin candles
made of paraffin obtained from the bogs of Ireland. I have here also a substance
brought from Japan, since we have forced an entrance into that out-of-the-way
place—a sort of wax which a kind friend has sent me, and which forms a new
material for the manufacture of candles.
And how are these candles made? I have told you about dips, and I will shew you
how moulds are made. Let us imagine any of these candles to be made of materials
Remove