The Romance of Modern Chemistry

HOW FIRE IS MADE tipped with a mixture of sulphide of antimony, chlorate of potash, and gum. They were ignited by being drawn between two folds of glass paper tightly pressed together, and a piece of this paper was supplied with each box. These matches required much pressure for ignition, and as they were liable to throw off sparks, they required careful handling. A shilling per box of eighty-four was the price, and it is instructive to compare this figure with the cost nowadays, when we can get as many as four hundred for a penny. The great modem development of the match industry began with the introduction of phosphorus. This element was discovered and its properties were known long before, but its application in the manufacture of matches began in the thirties of last century. Phosphorus in the ordinary condition is a wax-like substance which melts at 111° Fahrenheit, and takes fire very readily just above its melting-point. It is, in fact, this property of very ready ignition which makes phos- phorus valuable in the manufacture of matches. The slightest friction will cause it to catch fire, and hence if a splint of wood tipped with some mixture containing phosphorus is rubbed against a rough surface—for example, sand-paper—it will ignite immediately. The ignition is much facilitated by mixing the phosphorus with an oxidising agent, that is, a substance which contributes to the combustion of the phosphorus by supplying it with oxygen. Saltpetre, chlorate of potash, and red lead, which all contain a high percentage of oxygen, are the substances chiefly used for this purpose. In addition to these two essential constituents of a match- tipping mixture, namely, the phosphorus and the oxidising agent, there are also binding ingredients, generally glue, 122