Page:Popular Science Monthly Volume 20.djvu/592

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.

Mr. William H. Johnson, B. Sc, has described before the Manchester Literary and Philosophical Society, a series of experiments in the electrical resistance of iron and steel wire, from which he has drawn the conclusion that the amount of that resistance is a measure of the resistance of the iron or steel to tensile strain, and of the amount of combined carbon, sulphur, silicon, and phosphorus it contains.

The course of instruction in natural history of the Academy of Natural Sciences, of Philadelphia, which was begun in the spring of 1881, was resumed for the present winter in the first week in January. Courses of from twenty-five to thirty lectures each will be given, with practical demonstrations in the laboratory, on "Physiography and Invertebrate Paleontology," by Professor Angelo Heilprin, and on "Mineralogy," by Professor Henry Carvill Lewis. Professor Heilprin's lectures embrace general considerations relative to various features of the earth's structure and history, and the geological and geographical distribution of past and present life, with special attention in the latter half to practical paleontological demonstrations and advanced instructions. Practical work, including the methods of distinguishing minerals by their external and chemical characters, and blow-pipe analysis, is a regular feature of Professor Lewis's lectures.

Mr. Frederick Curry, an English botanist, distinguished chiefly for his studies of the fungi, died September 8th, aged sixty-two years. He had been Secretary, and was at the time of his death Vice-President and Treasurer of the Linnæan Society. His valuable collection of fungi is to be presented to the museum at Kew.

Professor J. P. Wickersham having been commissioned by the National Educational Association to inquire into the efficiency of education as a preventive of crime, reports that in the prisons of Pennsylvania, the colleges and high-schools are most insignificantly and the fairly educated classes only moderately represented, while one sixth of the crime of the State is committed by the wholly illiterate, who constitute only one thirtieth part of the population. He further concludes that about one third of the crime is committed by persons practically illiterate, mid that the proportion of criminals among the illiterate is about ten times as great as among those who have been instructed in the elements of a common-school education or beyond.

M. Pasteur has succeeded in communicating rabies by inoculation from the brain of a dog dead with the disease. He has also found that by trephining a healthy dog and placing in contact with its brain cerebral tissue from an infected animal, not only is the disease communicated with certainty, but the incubative period is in every case reduced to a few days.

The Surgeon-General of the United States Army reports that the proportion of cases on the sick list of the army last year was 1,768 per thousand of mean strength among the white troops, and 1,984 per thousand among the colored troops. The average number at one time was 44 per thousand of white, and 45 per thousand of colored troops. About one sixth of the number of white and less than one seventh of the colored sick were cases of wounds, accidents, and injuries. The proportions of deaths to cases treated were 1 to 190 among the whites, and 1 to 97 among the colored troops.

M. Fatio explains the theory of disinfection by sulphurous acid by remarking that the vapors of the acid act in two ways on all organisms that depend on oxygen for life, viz., by asphyxiating them through suppression of that element, and by gradually burning them interiorly, the acid being dissolved in their humors or aqueous parts.

A catalogue of the phenogamous and vascular cryptogamous plants of Indiana, prepared by the editors of the "Botanical Gazette" and Professor C. E. Barnes, names 1,432 species, grouped under 577 genera, and is published, though not absolutely complete, to provoke further additions. The flora of the State is divided into four groups, each marked by the physical aspect of the region in which it is found. The regions may be called the "the river-valleys" "the lake-borders," "the prairies," and "the barrens." The prairie plants are disappearing faster than any others under pressure of cultivation. The splendid forests that originally covered the greater part of the State are rapidly disappearing, and a new race of plants is springing up in their place. New species are continually appearing along the rivers and railroads.

Another prehistoric canoe has been discovered while digging in the old bed of the Rhône, near the bridge of Gardou, France. It is excavated from an oak-log, which has been left with its natural form, except that the ends have been beveled so as to give a sharp form to the prow and stern. Braces were left in hollowing out the vessel, to extend across the inside and strengthen the sides, and five pairs of holes were bored in the side, for oars. The boat is about thirty-eight feet long, three feet wide, and two feet deep, and would probably hold about twelve men. It was considerably decayed, and was somewhat broken in getting it out, but has been deposited in the museum of Lyons in a tolerably sound condition.