Page:Popular Science Monthly Volume 44.djvu/589

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that the earth is spherical; that the land above the waters is only a protuberance on the surface of the globe; that the continents are grouped in the northern hemisphere; that there exists a universal attraction; that the elasticity of vapors is a motive power; that the continents have uprisen; and that chemical elements exist, more or less as Lavoisier conceived them.

The largest continuous distinct forest district in West Prussia is known as the Tucheler Haide, and extends over an area of thirty-five square miles. It is subject to great aud sudden changes of temperature. Snow has fallen as late as May 19th, and night frosts have occurred as late as the 1st and 3d of June. Prehistoric remains are found belonging to the later stone and to the bronze ages. The inhabitants are occupied almost entirely with forestry and agriculture. Polish is still the prevalent language, though German is now generally understood.

As to the speed with which the migration flights of birds are accomplished, Canon Tristram, in the British Association, quoted Herr G├Ątke as maintaining that godwits and plovers can fly at the rate of 240 miles an hour. Dr. Jerdon had stated that the spine-tailed swift, roosting in Ceylon, would reach the Himalayas, a thousand miles, before sunset. In their ordinary flight the swift was the only bird the author had ever noticed to outstrip an express train on the Great Northern Railway.

Tobacco juice is very useful to agriculturists as a remedy for sheep mange and an insecticide, but its value is greatly lessened by its rapid fermentability. Experiments are making in the French Department of Manufactures for a process for concentrating an extract which shall be rich in nicotine and capable of indefinite preservation. A colorless extract is also sought which cultivators may use upon flowers attacked by insects.

Photographs of the invisible are what M. Zenger calls two pictures which he took about midnight of August 17th from a window looking out upon the lake of Geneva. They gave weak images of the lake and of Mont Blanc, which could not be seen in the darkness. Mr. Bertrand remarks that invisibility is a relative term, the significance of which depends on the power of the observer's eyes. The photographs were taken with a light of very small intensity, and did not represent an invisible object. So sky-photographs taken in observatories show stars which can not be discerned by the most piercing vision.

The absorption of light by platinum at different temperatures was the subject of a recent memoir to the Academy of Sciences of Turin by Signor Rizzo. The author obtained pellicles of unoxidizable platinum under the action of heat the transparency of which he found increased with the temperature, especially in the more refrangible regions. The determination of this fact establishes a new correlation between light and electricity, the augmentation of the electrical resistance of a conductor being accompanied by an increase of transparency.

An International Congress of Applied Chemistry has been called by the Belgian Association of Chemists, to meet in Brussels August 4, 1894. A number of interesting subjects appertaining to biological chemistry are to be considered, including those of the establishment of a Review of Reviews of Pure and Applied Biological Chemistry; pure yeast in practical fermentation; new researches of the relations of oxygen and yeast; raw grains in brewing; studies on the morphology and physiology of vinegar eels; analyses of grains as suitable for brewing, distilling, and the manufacture of glucose; and analysis of molasses with a view to distilling. Communications may be addressed to M. H. Van Laer, General Secretary of the Congress, 15 Rue de Holland, Brussels.

According to one of the latest visitors to the Ainus of Japan, Mr. A. H. Savage Landor, the supposed pious ejaculations, on the strength of which these people have been credited with a religious system, are really execrations.

An examination of the molluscan fauna that accumulate in the fresh-water pipes of Paris, brought there from the rivers whence the water is drawn, has been made by M. A. Locard, of Lyons. The author's attention was given chiefly to the study of the changes the animals undergo in their new abode. The medium differs from that of their native one in that it is one of water in perpetual motion, that food supply is scant, that the temperature is more constant than in open air, and that there is no light. Under these conditions the animals appear diminished in size, pale in color, somewhat elongated in shape, probably by the mechanical action of the running water, and with shells uniform, glossy, brilliant, without incrustations and without vegetable deposits. Though their presence contributes impurity to the water, it is not enough, under ordinary conditions, M. Locard believes, to do harm.

The schooner Ripple, in which the Swedish explorers Bjorling and Kalstennius started in 1892 on their expedition to study the fauna and flora of the arctic shores, has been found by Captain Mackey, of the Aurora, of Dundee, fast in the ice of Carey Island, Baffin Bay. The vessel had been cleared of boats and provisions, indicating that she had been abandoned. The dead body of a man was found in a cairn on the shore; and in another cairn close by were manuscripts written in English, with in-