Democratic Sentinel, Volume 4, Number 5, Rensselaer, Jasper County, 12 March 1880 — POPULAR SCIENCE. [ARTICLE]

POPULAR SCIENCE.

Hydrophobia.— Mr. Gal tier, a learned professor fat Lyons, has been inoculating rabbits with the virus of mad dogs, in order to find whether the malady will yield to any treatment he may devise, but has not been successful. The madness shows itself in the rabbit in abont three weeks. M. Galtier finds that the virus of a mad dog will be as powerful, when presei ved in water, twenty-four houra afterward, as it was at first. The Damposcope.— This is the name given by its inventor, Prof. Forbes, of Anderson’s College, Glasgow, to an instrument designed to detect the pres ence of fire-damp in mines. The principle embodied in it is that when a tun-ing-fork is sounded and brought near a tube of a certain length full of air, the tube will resound to the note produced by the fork. By this machine the firedamp in a mine can be estimated to the amount of 0.5 per cent. It has already been adopted in some of the mines in Lanarkshire, Scotland. Ancient Mound.— An ancient mound resembling the Aztec mounds of the Mississippi valley has been discovered in Japan. A scientific examination of the remains that have been dug up from it furnishes reason for believing that cannibalism was practiced by the Japanese in prehistoric times. The human bones that were found among the bones of beasts gave evidence that the flesh upon them had been cooked, and the marks still left upon the joints are such as could have been made only by human teeth. Desert of Sahara.— Lieut. Seaton, U. S. N., a'tributes tlm origin of the Desert of Saraba to the destruction of the forests with which the banks of the Saharan streams were once lined. The inhabitants, being a pastoral people, destroyed the forests to secure pasturage. “ Consequent upon the destruction of the forests, the periodical rains were replaced by short, though violent, storms, the waters from which, instead of soaking in, as in the past ages, slipped by on the rocky masses, carrying away the rich surface-mold, and bringing about the drying of the springs, and, as a direct consequence, of the rivers.” The Human Ear. harps in a room, with the same number of strings, and each string perfectly attuned to a corresponding string in the other. Touch a string in one, and the corresponding string in the other will give out the same sound. Try another string, and its com spending tone will be sounded. So with all the strings. So with any combination of the strings. It would not matter how you played the one harp, the other would respond No doubt the response would be weaker. That is what one would expect ; but the response, as regards pitch and quality, would be almost perfect. Now substitute for one harp a human ear, and the conditions would, according to theory, be the same, except that the responsive mechanism of the ear is much smaller than that of the responsive harp., In the ear there are minute cords, rods or something, in such a state of tension as to be tuned to tones of various pitch; sound a tone, its corresponding rod or cord in the ear will respond, perhaps feebly, but still with energy sufficient to excite the nerve filament connected with it; the result is a nervous current to the brain, and a sensation of a tone of a particular pitch.— Good Words. **

Man and His Present Costume.— Sight and hearing are the two senses which the natural man, in common with the lower animals, possesses in great perfection, and it is evident that, in addition to its usefulness to him as a mere animal, the eye affords him interest and delight long before his other senses become intellectually developed. In the very earliest stages of his existence we have proof in scratched outlines of auimals that he observes with curiosity and pleasure the varieties of auimal form which surround him. In his progress toward modern civilization he rejoices iu beautiful combina ions of line and gorgeous arrangements of color. All through the long ages till the seventeenth century this is distinctly visible, but growing fainter from the sixteenth, and it is when modern discoveries and appliances in the nineteenth have placed almost unlimited means in his power of gratifying this instinct that it disappears altogether. Costume vanishes, utensils and weapons cease to be ornamented, or are ornamented with a conscious effort instead of natural impulse, beauty of form aud color no longer lia3 auy charm, and the eye bf comes indifferent. The ugliness of most things connected with our ordinary habits is most remarkable. A well-dressed gentleman ready for dinner or attired for auy ceremony is a pitiable example—his vesture nearly formless auil quite fo'dless if he cau have his will. His legs, unshapen props—his shirt front, a void —his dress coat, an unspeakable piece of ignobleness. Put it iuto sculpture and see the result. The genius of Pheidias might be defied to produce auything satisfactory. We see without disapproval ugly, shapeless, ignoble forms, and it must be remembered that these form the language iu -which the artist has to speak. The human form, the noblest and most interesting study for the artist, is distorted in the case of men’s dioss by such monstrous garments, and in the case of woman’s dress by extravagant, arrangements which impede all simple nobility and refined grace of movement.— Nineteenth Century.

Jupiter. —Jupiter’s diameter is about eleven times that of the earth, and his mean density is about a quarter that of the earth, or about a thr.i more than water. Now, a bulky body may be composed of heavy materials, and stiil, as a whole, be light, like an iron -ship or lump of pumice stone, that will float in water. The pumice lump is light on account of its vesicular forma'ion, so that the mass consists of heavy felspathic material and the air it contains. Extract the air, and the pumice loses its floating power, though sti’l far from heavy in proportion to its bulk. Most of the earth’s crust is formed of solids much heavier than water. Granites are more thaii two and a half times heavier than water, slaty rocks about the same, and so are ordinary limestones, the variations of all being from about 2.5 to 2.9. The ironstone group contains denser minerals; red hematite has a specific gravity of 4.5; magnetic ironstone, 4.5 to 5.2, etc., and many other ores are heavy. At some remote period, when only part of the now-solid earth had been condensed from gaseous and vapory matter our planet might have had a mean density like that of Jupiter, as its rocky materials contain between 40 and 50 per cent, of oxygen; and, while condensations and chemical combinations were going on rapidly, our globe must have been the scene of Thunders, lightnings, and prodigious storms. And it is probable that certain stars which have suddenly blazed forth with passing splendor have exhibited to us the spectacle of conflagrations extending over millions and billions of square miles. Color-changes in Jupiter— 3uch as those noticed by Mr. Browning and the writer in 1899-70—may have°been caused by soda-flames, though not fierce enough or extensive enough to add materially to his ordinary luminosity, which is estimated as always ex-

ceeding, though not in a very high degree, what it would Ye by mere reflection of light received from the sun.— Belgravia.