for 255 yards of Turkey-red cloth. "We are at present acquainted, among the derivatives from coal-tar, with about sixteen distinct yellow colors, about twelve oranges, more than thirty reds, about fifteen blues, seven greens, and nine violets; and a number of browns and blacks, besides mixtures of the several chemical compounds, giving rise to an almost infinite number of shades and tones of color. These colors are capable of a rough arrangement according as they are originally derived from one or other of the hydrocarbons contained in the coal-tar. In the class called azo-colors, an azo or nitrogen group replaces the hydrogen in phenols and amido-compounds. They are chiefly bright scarlets, oranges, reds, and yellows, with a few blues and violets. Next in importance to the color industry comes the still more novel discovery of the synthetical production of antipyretic medicine. The initiative in the production of these compounds was given in the discovery by Professor Dewar, in 1881, that quinoline, their basis, is an aromatic compound; from it he obtained aniline. Kairine, the first of the antipyretics in the order of discovery, is manufactured from quinoline. It effects a remarkable lowering of the temperature of the body, which, however, is of much shorter duration than that effected by quinine; but, with the exception of its burning taste, it exerts no such evil effects as are often observed after the administration of large doses of quinine. Antipyrine, the second of these febrifuges, was discovered in 1883. It is made from aniline and aceto-acetic ether. As a febrifuge, it is superior in many respects to kairine and even to quinine. It equals kairine in the certainty of its action, while in its duration it resembles quinine. It is almost tasteless and odorless, is easily soluble in cold water, and takes the form of a white crystalline powder. Its use in medicine is accompanied by no drawback. A third artificial febrifuge is thalline, which is said to be used as an antidote for yellow fever. None of these substances are anti-periodics; and consequently they can not supplant quinine in cases of ague and intermittent fevers. Another group of coal-tar products comprises the artificial aromatic essences. Among these are cumarine, the principle of "new-mown hay"; vanilline, of vanilla, with its derivative vanillen, which is used in preparing "essence of heliotrope"; mirbane, a soap-perfume, and the artificial oil of bitter almonds. The most remarkable of all the coal-tar products is probably saccharine, a substance which surpasses sugar in sweetness. It is not a sugar, for it contains sulphur and nitrogen, nor does it act as a nutriment, but it is non-poisonous, and passes out of the body unchanged.
A Lesson in Practical Anthropology.—Sir C. W. Wilson, in a paper read in the British Association, on "The Wild Tribes of the Soudan," after describing the tribes and their clans, with their divisions and alliances, remarked that it was interesting to observe how thoroughly General Gordon had understood the situation in that region, and at once pointed out the remedy. When he left England, his instructions had been to proceed direct to Suakin, open up communication with the supreme sheik of the Hadendowas who had taken no part in the rebellion, and isolate and crush Osman Digma by raising against him the surrounding tribes, whose sheiks he knew personally. There can be little question that if this policy had been carried out early in 1884, before Sinkat fell and Baker Pasha had been defeated, it would have been successful. But, unfortunately, General Gordon's plans were changed and he proceeded up the Nile. Mr. Hyde Clarke congratulated the section on having had such a paper submitted to them, and said that Sir Charles Wilson had given them a useful exemplification of the value of anthropological studies. They had seen how incidents in the war in the Soudan had turned rather on the knowledge of the men than of the physical features of the country.
Photography of the Stars.—Professor Edward S. Holden has given, in the "Overland Monthly," a popular account of the methods and an estimate of the expectations of stellar photography. The photographic telescope requires special construction and arrangement of the lenses, which differentiate it from ordinary telescopes. If it is set fixed, the image of the star passing across the sensitive plate will leave a "trail," which is the visible representative
