Page:Amazing Stories v08n02 1933-05.djvu/7





HE metal aluminium, which has the better termination, although the word aluminum is very common, ranks as the third commonest element on the surface of the earth. Any number of rocks contain it with various other constituents. It forms the basis of clay, so that every one of our dinner plates or tea cups represents the compound of this metal with oxygen and sometimes with another element or elements in small proportion. The commonest pottery, such as a flower pot, is based upon the use of clay, which is the use of aluminium oxide. It is here that we meet with one of the curious variations in chemistry. Nothing can seem cheaper than a flower pot, but the identical aluminium oxide, crystalized and colored, it may be by chromium or some other element, gives us the ruby, the oriental emerald, the sapphire and other jewels, the ruby being practically at the head of the list in value.

It is a strange transition from a flower pot to a ruby; the latter weight for weight often exceeds the value of a diamond of corresponding size.

The color of the perfect ruby is expressed by the words “pigeon’s blood.” Artificial rubies are made by a fusion process and are colored by a very little chromic acid. Artificial sapphires made in the same way are colored by a trace of titanic oxide.

The Romans and other nations at the beginning of the Christian era collected salts from the surface of the ground in the volcanic regions, and among them aluminium sulphate. This gave them a mordant of great power for fixing the famous purple of Tyre upon the fabrics which they wove.

The women of antiquity were kept busy weaving fabrics. It is a strange thought that when man wanted to make a cover for his body, he started with thin threads and to effect the dying of the fabrics aluminium and iron salts came into play, and in this way the world drifted along for centuries. When beautiful rubies were brought from Burmah it never occurred to the monarchs, whose crowns were adorned with such jewels, that the composition of these beautiful rubies differed very little from the material of the commonest earthenware.

T was not until the eighteenth century that chemists awoke to the idea that what we call chemical compounds were additive. They had formulated the absurd theory before this period, that when a metal was oxidized, and of course gave an oxide weighing more than the original, a mysterious thing called phlogiston had been removed from it, thereby increasing its weight so that actually this theory, which was upheld for some time in all its absurdity, reminds us of the stories of negative gravity, which have been written by such writers as H. G. Wells.

Lavoisier, the great French chemist discarding the absurd idea of phlogiston following along with the Englishman, Priestley, who had come to America, developed the additive theory of chemistry. Thus alumina or clay or rubies are formed by the addition of oxygen to the metal aluminium.

It was in the early days of the nineteenth century that the great English chemist, Sir Humphrey Davy, was using the primary electric battery to attack and