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 beautiful
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 which
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
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