Popular Science Monthly/Volume 8/March 1876/Miscellany

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Exhibition of Scientific Apparatus.—There will be opened next April, at the South Kensington Crystal Palace, London, a universal exposition of scientific instruments. This exposition will continue for six months. Its object is to bring together as large a number as possible of scientific instruments possessing an historic interest, for instance, Tycho Brahe's astrolabes, Galileo's telescopes, Lavoisier's balances, Franklin's lightning-rods, the remnants of Charles's balloons, Giffard's injector, Leon Foucault's pendulum and gyroscope, etc. All the cost of transportation will be borne by the Department of Arts and Sciences. The home committee consists of one hundred scientific men, with the lord-chancellor. It is stated in the Moniteur Industriel Belge that an invitation has been sent to every civilized nation to take a part in the exhibition.

Fossil Coniferæ.—Prof. J. W. Dawson, in the American Journal of Science for October, invites correspondence from geologists who have examined the remains of coniferous trees in the carboniferous rocks of the United States. Hitherto, he says, little attention seems to have been given in this country to these remains of ancient vegetation. In Nova Scotia, several species are known, and are to some extent characteristic of definite horizons. In the carboniferous sandstones of the United States such remains seem to be frequent, but Dr. Dawson has seen no detailed account of them. The subject, he adds, is deserving of the attention of microscopists in the coal districts, as there can be little doubt that several interesting species remain to be discovered; for instance, the curious dictyoxylon of Williamson, found also in Nova Scotia, would probably reward patient slicing of trunks showing structure. The Devonian has treasures of the same kind. In the United States it has already afforded Dadoxylon Halli from New York, and D. Newberryi from Ohio, besides the curious Ormoxylon Erianum. No doubt other species remain to be discovered, especially in the Upper and Middle Devonian.

Habits of Hermit-Crabs.—In the American Journal of Science for October, Mr. A. Agassiz records some observations on the hermit-crab. He raised a number of these animals from a very early stage in their life till they reached the condition in which they require the protection of a shell. A number of shells, some empty, others occupied by living mollusks, were now placed in the glass dish with the young crabs. The empty shells were at once taken possession of. The crabs which were not so fortunate as to obtain untenanted shells remained riding about upon the mouth of their future dwelling, and on the death of the tenant, which generally occurred soon after in captivity, commenced at once to tear out the animal, and, having eaten him, proceeded to take his place within the shell. The question arises, How did the crab acquire the faculty of performing this act? Not by imitation, in this instance at least. Possibly by inheritance; Mr. Agassiz, however, is inclined to regard the act as purely mechanical—rendered necessary by the conditions of the young hermit-crab. "When the moult has taken place, which brings them to the stage at which they need a shell, we find important changes in the two hind-pairs of feet, now changed to shorter feet capable of propelling the crab in and out of the shell; we find, also, that all the abdominal appendages except those of the last joint are lost, but the great distinction between this stage and the one preceding it is the curling of the abdomen; its rings are now quite indistinct, and the test covering it is reduced to a mere film, so that the whole abdomen becomes of course very sensitive. It is, therefore, natural that the young crab should seek some shelter for this exposed portion of his body, and, from what I have observed, any cavity will answer the purpose; one of the young crabs having established himself most comfortably in the anterior part of the cast skin of a small isopod, which seemed to satisfy him as well as a shell, there being several empty shells at his disposal."

Position of Science in English Schools.—In their sixth report the British Commission on Scientific Instruction relate their observations on the state of science-teaching in public and endowed schools. The present state of scientific instruction in the upper schools is declared to be extremely unsatisfactory. The returns furnished by the public schools show that, even where science is taught, from one to two hours' work per week may be regarded, with very few exceptions, as the usual time allotted to it in such classes as receive scientific instruction at all. Moreover, the instruction in science is generally confined to certain classes in the school. Of the 128 minor endowed schools from which returns were received, only 18 devote as much as four hours per week to the teaching of science, and only 13 have a laboratory of any kind. The commissioners hold that science is a complementary and not an exceptional part of education; that it should not be regarded merely as a by-work, whether to satisfy the natural curiosity of most, or to develop the peculiar tastes of a few; and that, if need be, Greek should yield place to it in the universal curriculum.

Liebig's Influence on German Science.—Dr. Thudichum recently delivered a lecture before the London Society of Arts, on "Liebig's Discoveries, and their Influence on the Advancement of Arts, Manufactures, and Commerce." Toward the end of the lecture he indicates, as follows, one of the indirect effects of Liebig's researches: "The Prussian and other German universities now teach students of science and agriculture in great numbers, where thirty years ago law and theology filled the auditories. In that time the number of students of Protestant theology has decreased in Prussia from upward of 2,000 to less than 800, and in Hesse-Darmstadt from 50 to 13. One-sixth of all parsonages are without incumbents, because there is no one to receive the appointments. Such is the beginning of the great reformation which is now being wrought in human affairs by science."