Page:Popular Science Monthly Volume 20.djvu/441

Rh do not escape them entirely, they are less generally and less severely afflicted by contagious diseases; they are comparatively exempt from such diseases as consumption and scrofula; and they have the faculty of becoming acclimated and multiplying in all latitudes. These immunities are observed, notwithstanding the apparent condition of the Jews who enjoy them may be most miserable, notwithstanding the frequency of marriages of relatives among them, and notwithstanding the unwholesome conditions of the city life to which they mostly confine themselves. They may be explained as the consequence of the operation of a variety of causes, among which are suggested an inherent superior vitality in the race; the continued preservation of its purity from admixture with foreign blood; the faithful observance of the rules of hygiene laid down in Deuteronomy, which are particularly adapted to hot climates and hot seasons; the salutary influence of early marriages, of the spirit of order and economy, of moderation in tastes, of a comparative severity of manners, and of the domesticity of Jewish family life. It may be, too, that the misery in the Jewish quarters of European cities is more apparent than real, and that their inhabitants are really better off than the people around them. The facts are brought out in the statistics from which these conclusions are drawn, that Jews are quite liable to cerebral affections, and also to diseases that afflict mature and aged persons. The latter fact is explained by the existence of a greater proportion of mature and aged persons among them.

Constitution of Comet b, 1881.—The spectral phenomena and constitution of the cornet were the subjects of several papers at the sessions of the French Academy of Sciences of June 27th and July 11th. Mr. Hugging stated that the lines as shown in his photographs indicated the presence of nitrogen with carbon and hydrogen, probably as cyanogen. M. Berthelot remarked that the exhibition of the lines of hydrocyanic acid would furnish an argument for the hypothesis of the electric origin of the light, as the spectra of acetylene and hydrocyanic acid are characteristic of the electrical illumination of a gas containing carbon, hydrogen, and nitrogen, whether free or in combination. M. Thollon described the nucleus as giving a brilliant continuous spectrum, and the nebulosity around the nucleus as showing three bands, one quite distinct, the others dim, separated upon a ground forming a continuous spectrum. The spectrum of the bands resembled that given by the blue flame of alcohol, and therefore indicated the presence of carbon or some of its compounds. M. Wolff recognized—1. A wide continuous spectrum, pale, but visible in all the regions of the comet; 2. A continuous spectrum, almost linear, lively bright, given by the nucleus; 3. The spectrum of the three bands—yellow, green, and blue—characteristic of the light of all the comets hitherto examined. The existence of a solid or liquid matter, luminous either by itself or by reflection, was indicated in the nucleus, and that of an incandescent gas, probably acetylene, in the surrounding nebulosity, while the light of the tail appears to come from a luminous or simply illuminated pulverulent matter. The polariscopic observations indicated the existence of reflected light, that is, of nongaseous matter endowed with the power of reflection. M. Thollon noticed the modifications that took place in the spectrum as the comet receded from the sun. The violet rays were soon extinguished, while the yellow and red rays continued of full brilliancy. The bands appeared nearer the nucleus every day till the first day of July, when they were seen on the nucleus itself. M. Thollon supposes that the mass of the comet is formed partly of an incandescent gas, characterized by the banded spectrum, and partly of an incandescent solid or liquid matter in a state of extreme division, emitting a proper white light, and also capable of reflecting a part of the light it receives from the sun.

A South African River-Antelope.—Major Serpa Pinto, the African traveler, found on the Cuchibi a new antelope, of curious and remarkable habits. It bears, he says, among the Bihenos the name of quichôbo and among the Ambuellas that of buzi. It is of the size, when full grown, of a one year-old steer, has dark-gray hair, extremely smooth, straight horns, about two feet long,