Not only is Spinel ruby related to corundum ruby in color and use, but the two are frequently associated together in nature. The gem gravels of Ceylon, Siam, Australia and Brazil contain both kinds of rubies, and the ruby mines of Upper Burmah, where the corundum ruby occurs in a crystalline limestone, produce also large quantities of Spinel rubies. Spinel rubies also come in large quantity from Badakschan, in Afghanistan, near the river Oxus, the name of Balas rubies, by which they are often known, being said to be derived from Beloochistan, or Balakschan. The Persians have a tradition regarding these mines that they were disclosed by an earthquake which rent the mountain in twain. The localities above mentioned furnish nearly all the Spinel rubies of commerce. A few have been found in North America at Hamburgh, New Jersey, and San Luis Obispo, California. But these localities have never afforded any appreciable supply. No Spinel rubies of great size are known. Bauer mentions as the largest known, two cut stones, one of 81 carats and the other 72½ carats, exhibited at the London Exposition of 1862. The King of Oude is said at one time to have possessed a Spinel ruby the size of a pigeon’s egg. Spinel occurs in many other colors besides red, such as orange, green, blue and indigo, as well as white and black. Occasionally colorless Spinels occur, and as they cannot be distinguished by their behavior in polarized light from the diamond, it is sometimes sought to substitute them for the latter. They can be detected at once, however, by their inferior hardness. While Spinels of any color, if transparent and free from flaws, make desirable gems, the only colors found in sufficient quantity outside of the red to make an appreciable supply are the blue and the black. The blue Spinels resemble the sapphire in color, though they are somewhat paler. They come chiefly from Ceylon and Burmah, where they occur together with the ruby Spinel. The black Spinel is known as Ceylonite, or pleonaste, and is also obtained chiefly from Ceylon, although occurring of quality suitable for cutting at Mount Vesuvius in Italy. Like the ruby, Spinel can be made artificially, the process being to heat a mixture of alumina and magnesia with boracic acid, and if the red color is desired, a little chromium oxide. The Spinel ruby seems to have been known to the ancients equally with the corundum ruby, and the two were probably often confounded. The natives of India call the Spinel the pomegranate ruby and believe to this day that it possesses valuable medicinal properties. Oliver Cummings Farrington. [Illustration: WHITE-CROWNED SPARROW. (Zonotrichia leucophrys). Life-size. FROM COL. CHI. ACAD. SCIENCES.] THE WHITE-CROWNED SPARROW. (_Zonotrichia leucophrys._)