Page:The fairy tales of science.djvu/108

82 scale-beams and watch-wheels that will never be affected by rust. In fine, aluminium seems to possess properties which render it useful in a thousand ways, and if the process by which it is obtained can be further simplified, it will prove an inestimable boon to mankind. The source of aluminium is inexhaustible, since it is the base of every kind of clay. About one-third of the weight of every brick, every stone-jar, and every tea-cup consists of this curious metal.

Who will say that alchemy is extinct? What science but alchemy would enable us to extract a metal having an intrinsic value equal to that of gold, from a lump of worthless clay?

The artificial formation of lapis lazuli is another brilliant achievement of modern alchemy. This mineral has always been esteemed for its beautiful azure-blue colour, and for furnishing us with the valuable pigment, ultramarine.

Before the chemist could produce ultramarine artificially, he required to know the composition of the natural mineral; before he could form a portion of lapis lazuli, it was necessary that he should pull another portion to pieces for a pattern. This preliminary operation was soon performed, and lapis lazuli was found to be composed of silica, alumina, and soda, three colourless bodies, with sulphur and a trace of iron, neither of which is blue. The chemist was not a whit disheartened at the absence of any colouring ingredient, as he knew