scorched by contact with a hot plate before they are dipped in the paraffin, after which the phosphorus composition is applied to the match. This composition is simply a mixture of phosphorus, glue, and chlorate of potash. The composition is spread upon a warm plate, and the matches dipped on the plate, so that a small quantity of the phosphorus mixture may adhere to the tip of the match. Every match passes through about seventeen people's hands before it is finished. I told you that in England we generally use chlorate of potash in the preparation of the phosphorus composition, whilst abroad nitrate of potash is usually employed. You know that when we strike a light with an English match a slight snap results, which is due to the chlorate of potash in the match. In the case of nitrate of potash no such snapping noise occurs. Some people are wicked enough to call them "thieves' matches." Just let me show you (in passing) how a mixture of chlorate of potash and sulphur explodes when I strike it. [Illustration: Fig. 11.] Now, then, comes a very remarkable story to which I desire to draw your attention. There were many disadvantages in the use of this yellow phosphorus. First of all, it is a poisonous substance; and what is more, the vapour of the phosphorus was liable to affect the workpeople engaged in the manufacture of lucifer matches with a bad disease of the jaw, and which was practically, I am afraid, incurable. A very great chemist, Schrötter, discovered that phosphorus existed under another form, some of which I have here. This, which is of a red colour, was found to be exactly the same chemical substance as the yellow phosphorus, but possessing in many respects different properties. For instance, you see I keep this yellow phosphorus under water; I don't keep the red phosphorus in water. Amongst other peculiarities it was found that red phosphorus was not a poison, whilst the yellow phosphorus was, as I told you, very poisonous indeed. About two to three grains of yellow phosphorus is sufficient to poison an adult. I have known several cases of children poisoned by sucking the ends of phosphorus matches. So you see it was not unimportant for the workpeople, as well as for the public generally, that something should be discovered equally effective to take the place of this poisonous yellow phosphorus. [Illustration: Fig. 12.]