# Popular Science Monthly/Volume 44/February 1894/Notes

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A Correction.—The article on Vegetable Diet, by Lady Walb. Paget, which appeared in the Monthly for November, 1893, was reprinted from the Nineteenth Century, to which magazine it should have been credited.
The Franklin Institute, Philadelphia, has the awarding of certain medals for meritorious discoveries and inventions which will contribute to the promotion of arts and manufactures, as follows: The Elliott Cresson medal, gold, for some discovery in the arts and sciences, or for the invention and improvement of some useful machine, or for some new process or combination of materials in manufactures, or for ingenuity, skill, or perfection in workmanship; the John Scott Legacy Premium (twenty dollars) and medal, bronze, for useful inventions; and the Edward Longstreth medal of merit, silver, for useful invention, important discovery, and meritorious work in science or the industrial arts, or contributions to them. Persons desiring full information on the subject may correspond with William H. Wahl, secretary.
M. Dybowski, in a recent journey in the interior of Africa, encountered a tribe who have reduced cannibalism to such a system that they have only one object of purchase—slaves to be eaten. They refuse to sell food or any other products of their country for anything else, and the surrounding tribes capture and export canoe loads of slaves for this purpose.
Attention was recently called by M. Dollo in the Belgian Geological Society to some scientific conceptions of Dante. Thus there are references in the Commedia Divina, which was published about 1320, to the facts that the moon is the principal cause of the tides; that the surface of the sea is uniform except for the waves; that there exists a centripetal force, causing bodies to fall; ​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 Gätke 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 ​instructions to forward them to the nearest Swedish consul. The manuscripts have not been fully examined.
Prof. Frankland says that while the virility of many bacteria can be greatly reduced by successive cultivations, and the poisonous effects of such active bacteria as those of typhoid and cholera can be intensified by passing them repeatedly through the bodies of animals which at first offered great resistance to their pathogenic action, this increase in toxic effect can not be produced by artificial cultivation, and it has not been found possible to convert a harmless organism into a pathogenic one.
A curious case of resuscitation of an optical image has been described by Prof. T. Viguoli from his own experience. After a railway journey in a bright sun and two days' walking in the heat, he looked from the room in which he was engaged in conversation upon a balcony standing out in the bright sunlight. Early in the morning two days afterward, while lying awake in bed, he saw upon the ceiling an exact reproduction of the balcony, in all its colors and details. The image disappeared on closing the eyes, and reappeared on opening them again. Its appearance was not changed when it was regarded with one eye, looking with either alternately. It was interrupted by putting the finger in front of the eye, and responded in every respect to the usual features of ordinary vision. A cage of birds which hung upon the original balcony appeared, swinging as the real cage did.
What is undoubtedly the first publication of Asa Gray, although it is not included in the published lists of his writings, has been sent to Garden and Forest. It is a catalogue of the indigenous flowering and filicoid plants growing within twenty miles of Bridgewater, Oneida County, New York. It consists of nine pages, is dated January 1, 1833, or when the author was just in his twenty-fourth year, and is contained in the forty-second annual report of the Regents of the University of the State. It is also included in Prof. Britton's List of State and Local Floras of the United States and British America, where it is entered under Onondaga County.
Concerning his experience with horseshoes of aluminum, M. Japy reports that as that metal is four times lighter than iron a complete outfit of shoes of it will weigh no more than a single iron horseshoe. Horses accustomed to iron shoes when shod with shoes of aluminum imagine themselves barefooted, and are as careful in planting their steps as if they were unshod. The shoes open out as the hoof expands, and consequently never cramp it. An aluminum horseshoe will last from forty to sixty days, according to the composition of the alloy and the kind of work done by the horse. M. Japy concludes that aluminum can be utilized in shoes for race and carriage horses, and that it may be of service in the treatment of diseases of the hoof. It should, however, be used-only by persons experienced in working the metal.
An instrument which he calls a formenophone has been invented by a French engineer, M. E. Hardy, for detecting the presence and estimating the proportions of gaseous impurities of an atmosphere by the sound they give in a pipe. It is based upon the principle that air passing through an organ pipe gives a definite and constant tone, while if any other gas is mixed with it the tone varies according to the gas and the quantity of it. Two instruments of similar construction are used—one arranged so that pure air, the other that the air to be measured shall be made to pass through pipes of identical construction.
The importance of taking thorough precautions in the case of animals dying of infectious disease is newly illustrated in an observation made by the Russian Diatroptoff. The water of a particular well was supposed to be the cause of an epidemic outbreak of anthrax among certain sheep. No contamination was found in the water, but the mud at the bottom of the well contained a microbe which produced anthrax on being inoculated into a sheep. The germs are supposed to have percolated through the soil to where they were found. The anthrax among the sheep ceased on the well being closed.
In a paper on Grinding and Polishing, Lord Rayleigh, after referring to the accuracy with which optical surfaces can be worked, said that the operation of grinding did not produce scratches on a glass surface, but that pits were cut into an otherwise plane surface by it. A surface so ground, when used for a lens, gave excellent definition, but great loss of light by irregular reflection. To remove this defect the lens had to be polished, by which operation the pits were gradually removed. He gave reasons for believing that in the process of polishing the glass was worn off molecularly, whereas grinding removes fragments of the glass. He found that in polishing a certain thin disk of glass a thickness equal to about six wavelengths of yellow light was removed. It was easy to remove as small a depth as half a wave-length by means of hydrofluoric acid if proper precautions were taken.
Molds differ from bacteria, according to Prof. Frankland, in their action, and produce an oxidation, or burning up, instead of fermentation.
A new section, that of physiology, has been formed in the British Association. It is the ninth section, and will be designated by the letter I.