# Popular Science Monthly/Volume 43/July 1893/Notes

Layout 4
Japanese jugglers have exhibited a trick which consists in throwing knives at a person extended against a structure of boards, into which the knives appear to stick alarmingly close to the subject. The trick has been copied or imitated by European prestidigitateurs; but instead of real knife throwing and sticking, an illusion is arranged. Knives are hidden in recesses in the board structure, skillfully concealed by shutters, which open by a spring controlled by the target-subject. When a knife is thrown he moves one of these springs, and causes the hidden knife to emerge and appear as if stuck in the board, while the shutters instantly close; or the same is effected by means of wires controlled by persons behind the scene. The operator who throws the knife either casts it skillfully behind himself, among the scene-slides, or else throws it so that it shall strike, not into the boards, but on one side, where it falls noiselessly upon the carpet. The latter method is the best, because it enables the spectator to see the knife pass across the stage.
A full account of the Polynesian canoe is in preparation by Dr. N. B. Emerson, of Honolulu. The author points out in an article on the subject that the various migrations of the ancient Polynesians and their progenitors, from whatever sources derived, must have been accomplished in canoes or other craft, and that the waa, the pahi, etc., of to-day, however modified they may be under the operation of modern arts and appliances, ​are the lineal descendants of the seagoing craft in which the early ancestors of the Polynesians made their voyages generations ago. He holds, therefore, that a comparative study of the canoes can not fail to shed light on the problems of Polynesian migrations and relationships.
The presidents of sections of the British Association for its meeting at Nottingham in September are: Section A, Prof. R. B. Clifton; Section B, Prof. Emerson Reynolds; Section C, Mr. J. IT. Teal; Section D, Canon Tristram; Section E, Mr. Henry Seebohm; Section F, Prof. J. S. Nicholson; Section G, Mr. Jeremiah Head; Section H, Dr. Robert Munro.
The summer course in botany of the Torrey Botanical Club and the College of Pharmacy of the City of New York includes an annual course of ten lectures delivered between the last of April and July 1st, with ten conducted excursions—having the nature of extended out-of-door lectures—into the woods and fields. The course is provided as a means of instruction for business and professional men and women desiring to become practically acquainted with the chief principles of the science and with the local flora, but who have not the ordinary means of study provided by the schools and colleges.
A memorial volume is announced to be published by Wilhelm Engelmann, Leipsic, in honor of the seventieth birthday of Rudolf Leuckhart. It will include numerous contributions in the lines of their work by grateful pupils of Leuckhart, and will be illustrated by a portrait in heliogravure, forty plates, and forty-three figures in the text. In the list of contributors we observe the English names of Charles W. Stiles, C. L. Herrick, G. Herbert Fowler, Edward Laurens Mark, and C. O. Whitman, editor of the American Journal of Morphology.
A discovery made by Mrs. Zelia Nuttall and a reconstruction of the calendar system of the ancient Mexicans are described in the Report of the Peabody Museum of American Archæology and Ethnology as showing from astronomical data that the Mexican calendar has an antiquity of at least four thousand years.
An interesting testimonial was recently presented by Italian men of science to Prof. Maurice Schiff, of Geneva, on the occasion of his seventieth birthday. Prof. Schiff was from 1863 to 1876 Professor of Comparative Physiology in the Istituto dei Studi Superiori in Florence, where he introduced valuable improvements in teaching. He retired from that chair in consequence of the agitation excited against him by the anti-vivisectionists. He went to the school at Geneva, where he has acquired great fame and popularity. During his career he has enriched medical literature with many valuable contributions. The testimonial to him is an illuminated text on parchment, conveying the esteem and admiration in which his character and career are held, composed in Latin by Prof. Cavazza, and signed by an imposing number of surgeons, physicians, and medical teachers.
Investigations of the fermentation of tobacco by Suchsland have resulted in the discovery of different kinds of micro-organisms as active agents in the operation in the several varieties. Pure cultures of bacteria obtained from one kind of tobacco and inoculated upon another kind generated in the latter a taste and aroma resembling those of the tobacco from which they were taken. The discovery is greatly calculated to simplify the imitation of the finer varieties of tobacco.
An immunity against cholera is claimed for habitual users of vinegar, which is attributed by Mr. Hashimodo to the acetic acid contained in the best vinegar—a substance deadly to the comma bacillus. These bacilli were killed in fifteen minutes in an experiment in which they were treated with a vinegar containing only from three to four per cent of acetic acid.
The latest application of aluminum is to visiting cards, which are described as being thin, flexible, brilliant with a metallic luster, light, and admitting an impression of the names as distinct as it is made on paper. They can be made at a cost of about a dollar a hundred.
The results of experiments by Prof. Marshall Ward tend to prove that the action of sunlight is a far more powerful agent in the purification of the atmosphere than has hitherto been recognized. The author has discovered, for instance, that the anthrax bacillus, while it will withstand the greatest extremes of temperature, is killed by direct sunlight. Water is also thus purified.