Page:The fairy tales of science.djvu/311

 taken by the English in the Sikh war; that it was one of the chief attractions of your Great Exhibition in 1851; and that it has since been recut and placed among the jewels of your queen. "Such is the history of that marvellous gem which, in point of size, is still without a rival, though cutting has reduced it to little more than one-third of its original weight. You would probably like to know something about the previous history of this stone. I could tell you how it was originally formed, and how it came to be deposited with the gravel and sand of Golconda, but I have my own reasons for keeping these matters secret. Science will one day enable you to solve many problems connected with the formation of gems, and will perhaps teach you how to manufacture Koh-i-noors from coal or charcoal. Till then I shall keep my own counsel.

"Many of the jewels under my care are composed of alumina, and bear the same relation to clay, that the diamond bears to coal. Of these aluminous gems the rubies are the most valuable on account of their extreme rarity, their matchless hues, and the brilliant stars of light which they exhibit when viewed in certain directions. The sapphire, another of my precious charges, is merely a blue variety of the same substance as that which, when red, is called ruby.

"Flint, or silica, forms the base of innumerable