The Romance of Modern Chemistry

 NATURE’S BUILDING MATERIAL on. At last we arrive in this way at an irreducible minimum of substances which obstinately refuse to break up into anything simpler, and which cannot be converted into each other. These elements, as the chemist calls them, are, so to speak, the bricks out of which all known substances are built up. They number about seventy, and each kind of brick possesses characteristics which distinguish it from all the other kinds. That being so, it is not difficult to understand how the combination of the elements leads to all the infinite variety of nature. For the reader will see at once that if he was provided with seventy kinds of bricks, each kind with its own characteristic shade of colour, and if he was required to put together a structure containing at least two kinds of bricks, and up to any number of bricks of each kind, there would be a countless host of products. Now what are these seventy fundamental substances ? Many of them are familiar to the reader, by name at least; for example, lead, sulphur, gold, copper, phos- phorus, oxygen, mercury, tin, hydrogen, silver, and carbon. But quite half, probably, of the elements are unknown, even by name, to the ordinary individual, whilst to the chemist himself they are frequently not much more than names. And this is not to be wondered at; for the importance of some of the elements, judged by the part they play in the building up of the world and in the service of man, is extremely small. Thus glucinum, gallium, scandium, and many others would not be much missed were they to disappear altogether from the family of the elements. Any one who wants to understand something of the fascinating science of chemistry must be quite clear 30