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.
Fig. 12.
I should like to show you what very different properties these two kinds of phosphorus possess. For instance, if I take a small piece of the yellow phosphorus and pour upon it a little of this liquid—bi-sulphide of carbon—and in another bottle treat the red phosphorus in a similar way, we shall find the yellow phosphorus is soluble in the liquid, whilst the red is not. I will pour these solutions on blotting-paper, when you will find that the solution of the yellow phosphorus will before long catch fire spontaneously (Fig. 12 A), whilst the solution (although it is not a solution, for the red phosphorus is not soluble in the bi-sulphide of carbon) of the red phosphorus will not fire (Fig. 12 B). Again, if I add a little iodine to the yellow phosphorus, you see it immediately catches fire (Fig. 13 a); but the same result does not follow with the red phosphorus (Fig. 13 b). I will show you an experiment, however, to prove, notwithstanding these different properties, that this red and yellow material are the same elementary body. I will take a little piece of the yellow phosphorus, and after igniting it introduce it into a jar containing oxygen, and I will make a similar experiment with the red phosphorus. You will notice that the red phosphorus does not catch fire quite so readily as the yellow. However, exactly the same result takes place when they burn—you get the same white smoke with each, and they combust equally brilliantly. The red and yellow varieties are the same body—that is what I want to show you—with different properties.
Fig. 13.
Then comes the next improvement in the manufacture of matches, which is putting the phosphorus on the box and not on the match. This is why the use of red phosphorus, was introduced into this country by Messrs. Bryant and May. I have no doubt that many a good drawing-room paper has been spared by the use of matches that light only on the box.
I cannot help thinking that the old tinder-box, which I have placed on the table in a prominent position before you to-night, feels a certain pleasure in listening to our story. Envious perhaps a little of its successor, it nevertheless fully recognizes that its own reign had been a thousand times longer than that of the lucifer match. If we could only hear that tinder-box talk, I think we should find it saying something of this kind to the lucifer match—"I gave way to you, because my time was over; but mind, your turn will come next, and you will then have to give way to something else, as once upon a time I had to give way to you." And that is the end of the first chapter of my story of a tinder-box.