Page:Popular Science Monthly Volume 22.djvu/446

432 Professor of Physics in the University of Naples and Director of the Seismological Observatory on Mount Vesuvius, has recently died, at the age of seventy-five years. He was appointed to the two posts in connection with which he has gained scientific renown in 1854, and has since pursued the study of earthquakes and the phenomena associated with them, with a real devotion. He was the inventor of an electro-magnetic seismograph, by which the most delicate indications of subterranean action could be detected.

has recently submitted to the French Society of Encouragement a new substance, which he has named, after himself, "poteline," and which appears to be susceptible of numerous applications. It is a mixture of gelatine, glycerine, and tannin, and is, according to the inventor, absolutely impermeable to the air. When warmed, it becomes liquid, or nearly so, and takes all the contours of an object. M. Potel has made corks of it, which form an economical substitute for metallic capsules, and secure an hermetic closing. He has used it as a coating to preserve meat. At a temperature of 112°, it envelops the meat, kills the genus of putrefaction, and prevents any new germ passing in. According to M. Potel, meat thus treated will retain all its freshness for two months.

to the experiments of M. Demarcay, the metals which are generally regarded as fixed, even iron, give out real vapors at relatively low temperatures. Cadmium, for example, volatilizes at 257° and zinc at 302°. Magnesia had already been found to be volatile below a red heat, when acted upon by water and chloride of silicon.

the aid of M. Lippman's electrometer, M. Trousseau has succeeded in measuring the electrical conductibility of the poorer conductors, particularly of glass. Common glass is very perceptibly conductive, Bohemian glass is less so, while cut glass has no sensible conducting powers. M. Dumas regards this classification as repeating from the electrical point of view the one which he has established as dependent on the presence of alkaline salts in the vitreous mass; of which cut-glass has none, Bohemian glass very little, and common glass a considerable quantity.

founder of the Russian Geographical Society and President of the St. Petersburg Academy of Sciences, died in August last. His name is identified to a considerable extent with the history of Russian polar and exploring expeditions, and with the discovery of some island groups in the Pacific. He had published narratives of his Arctic expeditions and of a voyage round the world.

fact that an aniline black can be formed with vanadium has provoked investigation into the feasibility of the production of that metal for commerce. MM. Osmond and G. Witz have found a considerable source of supply in the foundry-scorias of Creuzot, France, which contain two per cent of vanadic acid. The scorias have only to be treated with hydrochloric acid to obtain from them a green liquor which can be used directly in dyeing.

has been urged against the theoretical importance of the agency of insects in fertilizing flowers, that the insects relied upon are rare upon mountain-heights, where the flowers that should be fertilized by them are still abundant. The observations of M. Ch. Musset, of Grenoble, France, which range up to 10,000 feet in height, tend greatly to break the force of this objection. He finds that all the orders of insects are represented to the height of 7,400 feet, and that the number of nectar-seeking insects is proportionate to the number of flowers. The hours of wakefulness and of sleep of the nyctitropic flowers—the number of which is greater than is supposed—and those of the insects are synchronous. The apparent number of nectar-seeking insects, also, is related to the number of their favorite flowers.

Professor of Zoölogy at the University of Copenhagen, and Inspector of the Natural History Museum of that city, died October 23d, aged sixty-six. He was eminent in ornithology, and was author of a memoir on the birds of the Campos of Brazil, and of numerous papers in the scientific periodicals of Copenhagen.

has produced imitations of the forms of lunar craters, by turning a current of gas into a melted metallic mass at the moment when solidification is about to begin. He obtained exact representations of the different varieties of hollows shown upon the moon by using different metallic mixtures.

of Bristol, has proposed to the British Association a scheme for securing a complete record of published scientific work, the essential feature of which is, that each nation furnish a record of its own work and of that only, and exchange with all other nations for their records. National committees are to attend to the preparation of the records, the transmission of exchanges, the translating and the composition of the records into a single work, and an International Congress is to take care of the uniformity and the successful working out of the scheme.

death is announced, at forty-three years of age, of M. Georges Leclanché, the inventor of the oxide of manganese constant elements.