Page:Popular Science Monthly Volume 31.djvu/591

 On examination of specimens of the stones the author found their principal distinguishing characteristic to be the presence of spherical bubbles, rarely pear-shaped, or having stringy portions showing how they had moved, but with the ends always rounded, and presenting a cloudy appearance or an arrangement in wavy groups. In natural rubies the cavities are always angular or crystalline in outline, and are usually filled with liquid; or, sometimes they are arranged with the lines of growth, forming part of a feather, as it is called by jewelers. In many genuine rubies we find a silky structure which appears under the microscope to be a series of cuneiform or acicular crystals, usually iridescent. No traces of these have been found in the artificial specimens. The stones are about equally hard and of nearly equal specific gravity with genuine rubies. Their color is good, but not so brilliant as that of a very fine ruby. The syndicate of diamonds and precious stones of Paris has directed that all stones of this kind shall be marked artificial, else they will be considered fraudulent, and sellers of them will be dealt with accordingly.



retiring President of the American Association for the Advancement of Science, who will give the presidential address at the New York meeting, is Professor Edward S. Morse, of Salem, Massachusetts. He will review what American zoölogists have done to advance the doctrine of evolution. Professor S. P. Langley, of Washington, will enter upon the office of president at this meeting. The vice-presidents, who are to preside over the several sections, are: A. Mathematics and Astronomy, William Ferrel, of Washington; B. Physics, W. A. Anthony, of Ithaca, New York; C. Chemistry, Albert B. Prescott, of Ann Arbor, Michigan; D. Mechanical Science, Eckley B. Coxe, of Drifton, Pennsylvania; E. Geology and Geography, G K. Gilbert, of Washington; F. Biology, W. G. Farlow, of Cambridge, Massachusetts; H. Anthropology, D. G. Brinton, of Media, Pennsylvania; J. Economic Science and Statistics, Henry E. Alvord, of Amherst, Massachusetts.

American Public Health Association will hold its fifteenth annual meeting this year at Memphis, Tennessee, November 8th to 11th. The topics to be considered are: "The Pollution of Water-Supplies"; "The Disposal of Refuse Matter of Cities"; "The Disposal of Refuse Matter of Villages, Summer Resorts, and Isolated Tenements"; and "Animal Diseases dangerous to Man."

Indian Government has arranged a scheme for the complete and systematic botanical survey of India, for which purpose the country has been divided into four great districts, with a superintendent of survey in each. The flora of the Philippine Islands has been under study by Dr. Sebastian Vidal, Director of the Botanical Garden at Manila and the commission for studying the forest flora; and the work is provided for, for still another year at least, in the public budget.

in opening a new Industrial Institute at Bromley, England, recently, said that hitherto the country had prided itself upon the practical knowledge of its artisans, but it had relied too entirely upon that knowledge. The consequence had been that the countries which nurtured the intellects of the people had stepped in, and with their superior mental education had showed the world that the competition of the day was not one of local advantages, but a competition of intellect. England was realizing her position now, and training her sons by technical schools to compete intellectually with the countries round her, from whom she had learned her lesson.

in a paper on "House Construction in Relation to Health," suggests that great sanitary advantages might be gained if towns were laid out with the streets in the diagonal directions—northeast and southwest, northwest and southeast. Some of the suburban towns near New York are laid out in this way, and—the sun shining into all the rooms some time during every day in the year, and nearly every day into all the windows—the effect is very cheering and salutary.

fact is suggestive of the intensity of the strain of city life, that, while from 1852 to 1868 the population of Chicago increased 5·1 times and the death-rate 3·7 times, the deaths from nervous disorders increased 20·4 times.

are accustomed to inhabit the buildings at South Kensington while the exhibitions are in progress. When the exhibitions close, they become starved, and leave the buildings in obviously great numbers. The rat population appears to have been greater than ever during the recent Colonial and Indian Exhibition, and they appeared everywhere, even eagerly going into the traps, which they avoided at other times. At length they entered upon a struggle for existence among themselves, and kept it up till all the young and weaker rats were devoured. 