Sapphire is a word which is the same in nearly all languages. In Chaldean, Hebrew, Greek and Latin it has the same form as in modern tongues. This fact testifies to the ancient use of the stone. In early times sapphire was believed to be a destroyer of poison, so that if put into a glass with a spider or venomous reptile it would kill it. It was regarded also as a remedy against fevers. SPINEL. The group of Spinel includes in mineralogy a number of species of different though analogous composition. The Spinel employed as a gem is almost wholly confined to the magnesium aluminate, having the percentage composition alumina 71.8 and magnesia 28.2. This is usually of a red color, different shades giving gems known by different names as follows: Deep red, spinel-ruby; rose-red, Balas ruby; yellow- or orange-red, rubicelle; violet red, almandine ruby. Spinel is thus known among gems chiefly as a relative of the ruby, and this sort of Spinel will first be considered. The Spinel rubies differ from the true or corundum rubies in hardness, specific gravity and system of crystallization. The hardness of Spinel is 8, or about that of topaz, and the specific gravity 3.6. It is thus neither as hard nor as heavy as corundum ruby. Again, the system of crystallization differs. Spinel crystallizes in the isometric system and is usually found in the form, of octahedrons, while corundum ruby is hexagonal in crystallization. (See colored plate in November number.) Spinel is singly refracting in polarized light and corundum doubly refracting. Spinel ruby is infusible before the blowpipe, but on heating undergoes a curious series of changes in color which are quite characteristic. The red changes first to brown, and then becomes black and opaque, but on cooling the black changes to green, then becomes nearly colorless and finally the stone resumes its original red color. As a small percentage of chromium is usually found by analysis to exist in ruby Spinel, its color is generally considered to be due to this ingredient. While the Spinel ruby is considered of less value than the corundum ruby and is sometimes by fraud or error substituted for the latter, it yet has a definite value as a gem and is sold under the name of Spinel ruby or some of its varieties. This value is usually reckoned at about half that of the corundum ruby, although variations in quality of the stones, as well as changes in demand, cause differences of price. Thus Emanuel mentions a Spinel ruby of good quality weighing 40 carats, which in 1856 was sold for two thousand dollars, but which in 1862 brought at public auction only four hundred dollars. In 1866, however, it was again sold for twelve hundred dollars. The Spinel ruby of the French crown jewels, weighing 56 carats, was in 1791 valued at ten thousand dollars.