Page:Popular Science Monthly Volume 3.djvu/544

528 his late work on the "Physiology of Circulation," Dr. Pettigrew gives the following as the rate of the heart-beats in man at different periods of life: In the human foetus the heart beats 140 times per minute; at birth, 130; second year after birth, 100; third year, 90; fourteenth year, 80; middle age, 70; old age, 60, or even less. The variation in the frequency of the beat of the heart in the lower animals is still more remarkable.

the United States statistics, it appears that the percentage of insanity, idiocy, etc., is greater among the white population of this country than among the black. Thus, among the whites, one in 2,253 is deaf and dumb; among the colored race (blacks and mulattoes), only one in 3,780; insane whites, one in 943; colored, one in 2,750; idiotic whites, one in 1,575; colored, one in 1,530. The statistics of blindness, however, are more unfavorable for the colored race: blind whites, one in 2,000; colored, one in 1,469. The insane females, both white and black, outnumber the insane males, 19,202 against 18,179; but the male idiots are greatly in excess of the females—14,476 against 10,046.

is found in Bombay a minute variety of ants which surround their nests with a series of concentric circular walls an inch or an inch and a half high, and about the same distance apart, the innermost wall being the highest. The object of these walls or fortifications is not yet known.

a botanical exploration of the region around the river Coanza, in Lower Guinea, Dr. Welwitsch's party found their supply of provisions exhausted. The men accordingly went in search of food, with senses quickened by hunger. They were so fortunate as to discover an enormous mushroom, as large as an umbrella, which made soup enough to satisfy the hunger of 20 men. This specimen was the first of the species seen by Welwitsch, but subsequently he often met with it, and learned that these great mushrooms are brought to market at Pungo Adongo by the natives, and there sold at from one to three pence each, according to size.

act of Parliament of the year 1843, mechanics' institutes, literary and scientific associations, and the like, were exempted from local taxation in England. The Government now proposes to do away with the exemption, thus imposing a tax on knowledge. If the measure succeeds, many societies must close their doors, and the work of popular education will receive a serious check.

A "" to commemorate the services rendered to science by the late Prof. Liebig, is to be published by the Royal Bavarian Academy of Sciences, of which body he was president. The volume will contain an obituary notice of the deceased, and three separate dissertations upon the services rendered by him to physiology, agriculture, and theoretical chemistry, to be written by Profs. Bischof, Vogel, and Erlemeier.

amount of tobacco paying duty and cleared for consumption in Great Britain steadily increases. Thus in 1841 it averaged 13¾ oz. per capita; in 1851, 16¼ oz.; In 1861, 19½ oz.; and in 1871, 21½ oz.

average number of persons per house, in various cities of the United States, is as follows: New York, 14.72; Cincinnati, 8.81; Brooklyn, 8.64; Boston, 8.46; Jersey City, 8.37; Hartford has 5.56; Rochester, 5.36; and Toledo, the lowest, 5.20. The densest population is that of the Fourth Ward, New York, where there are 24.61 persons to each dwelling.

Russian Government is about to construct a railroad from Nijni-Novgorod on the Volga, to the Japan Sea, about 4,200 miles. This line, in conjunction with that from Nijni-Novgorod to St. Petersburg, will connect the Baltic Sea with the Pacific. The road will run east in latitude 56°, 850 miles to Tobolsk, crossing the Ural Mountains. From Tobolsk it will take a southeast course 1,500 miles to Irkutsk, on Lake Baikal (latitude 53°). The remainder of the route is not yet determined on, but it is expected that work will be commenced on the western end during the present year.

, near the Oswego Falls, is a noted fishing-ground, containing abundance of pickerel, pike, perch, bass, and indeed nearly all the fresh-water fish. But a sort of epizooty recently broke out among the pickerel, which threatens to utterly destroy all the fish of that species contained in the lake; indeed, it is believed that they are already destroyed. The other fish in the lake are not affected by the disorder.

has no very high opinion of the value of English university education. He said recently in Parliament that "a Scotch university teaches a man how to make a thousand a year, an English university how to spend it."

, of London, has sailed for the north-pole in the yacht Diana. Mr. Smith expects to join his supply-yacht, the Samson, at Cobbe's Bay, on the north-west of Spitzbergen, latitude 80°. From that point he will push as far northward as the ice will permit. He purposes returning home in one year at the farthest.