Note 41 — Chapter X · THE WONDERFUL EFFECTS OF HEAT—(concluded).

In the ordinary lucifer-match (an invention since Davy’s time) we have a striking illustration of the different temperatures required for various substances to enter into combustion. The phosphorus with which these lucifers are tipped becomes inflamed at a very low heat (60°), so that mere friction is sufficient to ignite it. This substance, in burning, produces heat sufficient to kindle the sulphur next to it; for this, as we have seen, enters into combustion at about 500°; and the sulphur again, in burning, raises the temperature sufficient to ignite the wood, which requires a heat of at least 1000° before it can be made to burn. Had the match been tipped with phosphorus alone, the phosphorus acid produced by the combustion would have incrusted the wood and prevented it inflaming. Before the use of phosphorus matches had become general, others were introduced, the tips of which were coated with a mixture of chlorate of potash and sulphur, and these had to be drawn forcibly through a piece of folded sand-paper, for this mixture requires a much higher heat in order to inflame it. Previous to the introduction of these, again, the common brimstone match was in general use. This, as is well known, was kindled by means of a spark in tinder—the tinder consisting of charred rag, and the spark, therefore, being merely a particle of charcoal at a red heat, while the ignition of the tinder itself was originally produced by the percussion of a piece of flint and steel, which evolved so much heat that small splinters of the metal were fused by it and fell upon the tinder in a red-hot state.