Page:Popular Science Monthly Volume 21.djvu/882

 Dr., of the Hartford (Connecticut) Retreat for the Insane, accounts for the increased amount of disease of the nervous system observed of late years, by reference to the larger part of the twenty-four hours which the masses of the people spend within-doors. A far greater part of the population than used to be are employed in counting-houses, business-offices, stores, and factories, inhaling a heated and contaminated atmosphere, the effect of which upon the delicate structure of the brain can not but be most unfavorable.

Mr., in his important pamphlet on "The Culture and Management of our Native Forests," says that we must learn to imitate Nature in our methods of cultivation, if we would grow new forests successfully. The primary point is to keep the trunks of the trees shaded. Nature does this by massing the plants closely together in the forests, so that they shade each other, or by giving a wide spread of limbs with low heads to trees in the open. It also protects the cambium layer with thick deposits of old bark, and we endanger the health of the tree when we scrape this off. Another important point is to keep the roots well mulched, as nature does with old leaves, thick mold, and mosses in the forest; and a third point is to protect the trees well from the southwest wind the breeze which, with its drying heat, is the most damaging to the vitality of the tree. In illustration of the validity of this rule Mr. Cleveland points to the greater luxuriance and variety of plant-life on the east side of seas and lakes than on the west side.

, of the University of Cambridge, lost his life about the 19th of July, while attempting the passage of the Aiguille Blanche de Penteret, one of the buttresses of Mont Blanc, in Switzerland. He was only about thirty years old, but had done a very large amount of original biological work for one so young. Having entered Trinity College, Cambridge, as a natural science scholar, he decided, upon the suggestion of Professor Michael Foster, to apply himself at once to original work instead of going through the ordinary routine preparation for his degree. He was afterwards encaged at the zoological station at Naples, and then at Naples and Cambridge alternately, and had just been honored by the creation of a special chair of Animal Morphology for him at the university. He was the author of a work of eminent merit on the "Development of the Elasmobranch Fishes," and had begun a work on "Comparative Embryology."

English unit, or parliamentary standard, for the estimation of the intensity of light, is a spermaceti-candle, six to the pound, burning 120 grains an hour. The French standard, or carcel, a lamp burning 42 grammes of refined colza-oil per hour, with a flame 40 millimetres high, is reckoned as equivalent to 9&#183;5 candles. The English standard for gas-lights is an Argand burner with sixteen holes, in a chimney five inches high and two inches in diameter, burning five feet of standard gas per hour, and giving a light of sixteen candles. The German standard, or Vercinskerze, is a paraffine-candle 20 millimetres in diameter, with a flame five centimetres high, 7&#183;6 of which are equivalent to a carcel. The variations of the carcel burner do not exceed two or three per cent, while those of the standard candles sometimes rise to thirty per cent.

later experiments of Professor W. O. Atwater and his aids on the effects of fertilizers and the feeding capacities of plants, as recorded in a paper just published by the Agricultural Department, indicate that Indian corn has a much greater power of gathering nitrogen from the soil or air or both than it has been credited with; that in this respect it comes nearer to the legumes than to the cereals; and that it may eventually claim a right to be classed with the "renovating" crops. The experiments are, however, not yet considered decisive. Professor Atwater, projecting a plan for continued experiments in the line to which his report is devoted, suggests that chemical and physical surveys of the land in behalf of agriculture ought to be undertaken, just as there have been topographical and geological surveys in behalf of other industries and interests.

The death is announced, July 16th, of Dr. George Dickie, Professor of Botany in the University of Aberdeen, Scotland, for seventeen years, and previously for several years in the Queen's College, Belfast. He retired from active duty, on account of impaired health, in 1877. He was the author of numerous papers and several books on botanical subjects. He was especially interested in the study of algæ.

, the philosopher and Professor of Political Economy, was drowned while bathing at Bexhill, near Hastings, England, August 15th. Professor Jevons was a grandson of William Roscoe, the merchant author, and was born in Liverpool, in 1835. He was connected with the Royal Mint at Sydney, Australia, for five years after 1854, and was appointed Professor of Logic and Moral Philosophy and Lecturer on Political Economy in Owens College, Manchester, in 1866, and Professor of Political Economy in the University of London in 1872. He was the author of several works in logic and political economy, which are recognized as authoritative.