Quotation from: General ScienceWritten by: Bertha M. Clark |
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For these reasons the introduction of the so-called safety match was an important event. When common phosphorus, in the dangerous and easily ignited form, is heated in a closed vessel to about 250 deg. C., it gradually changes to a harmless red mass. The red phosphorus is not only harmless, but it is difficult to ignite, and, in order to be ignited by friction, must be rubbed on a surface rich in oxygen. The head of a safety match is coated with a mixture of glue and oxygen-containing compounds; the surface on which the match is to be rubbed is coated with a mixture of red phosphorus and glue, to which finely powdered glass is sometimes added in order to increase the friction. Unless the head of the match is rubbed on the prepared phosphorus coating, ignition does not occur, and accidental fires are avoided.
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