From the remotest ages chemistry has exercised the strongest fascination on the minds of the curious, nor is it a matter of surprise that boys should feel themselves drawn strongly by its mystery and seeming magic. This attraction is undoubtedly caused by what the ancients called the elements, earth, air, fire and water. There is something so weird about the manifestation of air and fire, that it is not difficult to understand how the alchemists believed them to be forces able to be used at the bidding of spirits, who might be conjured up by incantations and spells.

Now it is known that these uncanny beings existed only in the imagination of the forerunners of modern chemists. Yet what boy can look on the brilliantly colored fires of a Fourth of July display, or the burnished gold of the setting sun, or the fantastic pictures in the glowing coals in a grate, and not feel that there is still something of magic and mystery in fire still? What the boy feels, the scientist cannot explain. Nobody knows actually what fire is. All that can be said is that fire is produced by certain substances, such as coals, wood, or paper, that give out heat, while passing from one state to another.

Now the word “element” was and is used to mean that simplest form of matter, which, with other simplest forms goes to make up the whole world of everything in it. The earth, animals, plants, the sea, the atmosphere, are all made up of one or more of some seventy substances called elements. Hence it is clear that the earth, air and water are not, as the ancients thought, elements at all. As will be seen in this little book, both air and water consist of mixtures of elements. In chemistry such mixtures are called compounds. This word occurs again and again, so its explanation should be remembered.

One great fact must be remembered, which is at the very root of chemistry. Nothing is really lost, however much its form may be changed, or however many changes it may pass through. For instance, it may seem that when a block of wood be burned that a very large amount of it is lost. If, however, the ashes, the smoke, and the carbon that is burned by the air be all weighed, the result would be exactly the same as the weight of the original block of wood.

Again take an instance of a different nature. A lump of sugar is placed in a small glass of water. Gradually the solid is dissolved, and in time disappears. It is not lost, however. By boiling the mixture until all the water has evaporated the sugar will be found adhering as crystals on the sides of the glass. If these be carefully collected, they will be found to weigh precisely as much as the original lump of sugar.

Once more, take a block of ice weighing an ounce. Having removed it into a room, the solid will in an hour or two have disappeared entirely, but the water that has replaced the block of ice will weigh neither more nor less than an ounce. If again heat be applied to the water it will all disappear, but if weighed in a jam jar, the steam, although invisible to the eye, will still weigh one ounce exactly.

From the above-given experiments it may be seen that, however matter may change its form it cannot really be destroyed. This truth will appear in every experiment that can be performed, whether those given in this little book or in the most learned treatise on chemistry.