Popular Science Monthly/Volume 3/July 1873/Miscellany

From Wikisource
Jump to navigation Jump to search


The New Planet Vulcan.—The observation of certain disturbances in the motion of the planet Mercury, and the appearance: it particular periods of well-defined circular black spots, passing rapidly across the disk of the sun, have led astronomers to suspect the existence of a ninth planet, interior to Mercury, and with a period of revolution, according to M. Leverrier, of 19.70 days. Such a spot was seen to cross the sun on March 26, 1859, the observer being a French physician named Lescarbault, who thereupon claimed the discovery of the planet, to which the name of Vulcan was assigned. It should be added, however, that other observers had previously witnessed a similar phenomenon. The spot was again seen by Mr. Lummis, of Manchester, on the 20th of March, 1862. From calculations based upon these and other observations, Mr. Hind, of the Twickenham Observatory, England, in a letter last year to the London Times, suggested 10 o'clock a. m. on the 24th of March, 1873, as the time when a conjunction of the supposed planet with the sun might be expected to occur. "If the hypothetical body," says Mr. Hind, "is not found upon the sun's disk at that time, it will be, I think, a sufficient proof that my surmises are incorrect." Prof. Kirkwood, in a recent letter to the Tribune, states that "Mr. Cowie has just reported the appearance of such a spot on the sun at Shanghai, China, on the morning of March 24, 1873, thus fulfilling the prediction of Mr. Hind, and rendering the existence of such a planet reasonably certain. Prof. Kirkwood's calculations, as given in the letter above quoted, make its sidereal period 34 days, 22 hours, 31 minutes. In a subsequent letter, Prof. Kirkwood calls attention to the fact that similar spots have been observed on the sun, at other dates, which cannot be referred to the same asteroid, and he thence infers the existence of a zone of minor planets within the orbit of Mercury. Why none of these have ever been seen during total eclipses of the sun he explains as follows:

"It is well known that a marked difference obtains between the light-reflecting capacities of the various planets of our system. Mercury, for instance, is in this respect very much inferior to Venus and Jupiter. (See Proctor's "Other Worlds than Ours," p. 67.) The difficulty, then, in regard to the invisibility of these asteroids when the sun is eclipsed, may be obviated by supposing their surfaces so constituted as to reflect but a small portion of the sun's light."

Education in Sierra Leone.—Mr. John Pope Hennessy, ex-Governor of Sierra Leone, delivered recently, before the London Society of Arts, an admirable lecture on "the British Settlements in Western Africa." We give a synopsis of that part of the discourse which treated of the state of education. It is the avowed purpose of the British Government to train the natives to habits of self-control, so that they may be finally suffered to govern the country themselves. But that no great progress has been made in the preliminary work of education is admitted on all sides. In 1869, "education was most inadequately provided for" in Sierra Leone. In 1870 the "conspicuous listlessness and inattention of the scholars" are noted by the Director of Public Instruction. In 1872 Mr. Hennessy was himself convinced that the system in use was only "an incentive to the formation of a thoughtless, idle, and indolent character." And at Cape Coast matters were still more unpromising. In 1872 the government chaplain calls loudly for compulsory education, because he cannot induce the scholars to attend to their duties.

That the fault does not lie with the natives is very satisfactorily shown by Mr. Hennessy. On his second visit to Lagos, King Docemo told him that all his chiefs and principal people were most desirous of having their children educated, but they did not want their religious ideas to be interfered with. The king's own son was obliged to quit a school under English control, being unwilling to believe in the teachers' "mission to enlighten the natives in matters of religion." All the "chiefs and captains of companies" at Cape Coast assured Governor Hennessy that "they would give any thing for a good education;" but their religion must not be interfered with. A few low-caste natives, they said, in hopes of promotion to clerkships and catechistships, would continue to frequent the English schools; but the only result would be "flagrant hypocrisy and idleness."

The same testimony was given by all the native chiefs whom Mr. Hennessy met. Bey Inca, King of the Small Scarcies, had sent his son to the Portuguese settlements, to learn Arabic and Portuguese, and he was about sending him now to Senegal, to learn French, and to complete his Arabic. That youth would one day be the ruler of a country on the border of the British settlement of Sierra Leone, and yet he would be ignorant of the English language—a thing deeply to be regretted, thought King Inca.

Purification of Bone-Black.—The refined bone-black of commerce is seldom possessed of the qualities usually ascribed to it. Its decolorizing properties are weak, and, besides, it always contains sulphate of lime, which dissolves in the liquids to be clarified. Herr Gräger, in Dingler's Journal, gives the following process for purifying bone-black: It is to be ground to powder, and then boiled in from four to six times its weight of water, containing 4 or 5 per cent, of carbonate of soda. After standing four days, the water is drawn off, and hot water poured on instead. This having been in turn drawn off, the bone-black is next treated with commercial chlorhydric acid, and again heated. The latter treatment is followed until the liquid is no longer turbid from the presence of ammonia. The amount of acid to be used is much greater than is commonly supposed. The next step is to wash with common water, to filter with distilled water, and to dry the bone-black at a temperature of from 212° to 248° Fahr. One hundred parts of crude bone-black yield 20 parts refined. The product is a light powder, very fine, with intense decolorizing power, and but a small quantity need be used to produce the required effect.

The Mistletoe.—The following, over the signature of R. W. Newberry, occurs in the New York World: "About last Christmas-time I noticed on two occasions in the World that the existence of the 'mistletoe' in this country was doubted. I knew of its existence, but didn't want to make the assertion till I had the proof, which I enclose herewith. I found it on Staten Island many years ago growing on pepperidge-trees. In Maryland it affects the same tree, and also the oak. There is plenty in Virginia, and the specimen I send you was collected from a persimmon-tree at the Bangle Gold-Mine, near Concord, Cabarrus County, N. C, which place I had occasion to visit last week. The number of days it has been gathered and the journey have rather spoiled the sample."

Prof. S. Lockwood says that the false, or American Mistletoe, used to be found on the Nyssa multiflora, the pepperidge, or gum-tree, in Mercer County, N. J., which probably is its northern limit in the Eastern States. But this is not the true mistletoe of Europe, which belongs to the genus Viscum. The American parasite is the Phoradendron flavescens. It infests a number of the deciduous trees, and almost covers some of the oak-trees in Plaquemine Parish, La. The professor says that he received specimens in full bloom, last January, from that locality.

The statements of the Torrey Botanical Club, in regard to certain illusions concerning the English mistletoe, will be interesting in this connection. The idea that the English plant is limited to the oak is an error, it being believed that it is not to be found on more than three oak-trees in all Great Britain. There are but few people in England that have seen it grow at all, and they have generally found it on the apple and wild-crab trees. And yet, as a decoration, with holly, ivy, and laurel, it abounds at Christmas, and is bought with these plants at two-pence a bunch. This genuine English mistletoe under which the girls are kissed in the Christmas-games, is a sort of "pious fraud," being imported in enormous quantities into England from Belgium in immense crates. In Belgium it is plentiful on old and exhausted apple-trees. Indeed, the real Druid mistletoe of the English oaks has become almost like that ancient personage, a thing of the past.

A Viviparous Fly.—In the American Naturalist is an interesting account, by Prof. Lockwood, of the Sarcophaga carnaria, a species of flesh-fly, which brings forth its larvæ or maggots alive, instead of laying eggs. Fine engravings are given of the fly, its pupa, and larva. The professor succeeded in rearing some of the grubs until they became perfect flies, it requiring 13 days to effect the complete series of changes. One of the grubs he put alive into 95 per cent alcohol, in which fluid it sustained life 134 minutes. This larva was six days old. One seven days old was placed in turpentine, where motion ceased only at the end of 27 minutes. One in essence of peppermint lived 70 minutes; and another, in Fowler's solution, only ceased to manifest motion at the end of 53 minutes.

From these experiments Dr. Lockwood is led to remark: "In the light of such facts, what reprobation is too severe upon the useless and cruel practice of drenching horses with violent medicaments for the bots? The ailment thus known is due to the presence in the animal's stomach of the larvæ of the bot fly (Gastrophilus equi), which clings to the walls of the stomach by its formidable mouth-hooks." As further evidence of the tenacity of the larvæ of certain flies, this naturalist says: "Long ago my attention was called to the tenacity of larval life when exposed to poisons, I was forced by the claims of justice to take part in a toxicological examination of the internal organs of a person who had been nine months buried. These were put in a large glass jar, and the jar filled with water. It was summer. In three or four days, I noticed the presence of a great number of large white larvæ, doubtless of the common blow-fly. We obtained enough bichloride of mercury to establish the fact that the woman had died by taking a very large quantity of this terrible poison. Naturalists know how well this drug will preserve animal tissues. And in this case, the blood in the capillary vessels was of a bright color, as if fresh. And, despite the presence of so much poison, the larvæ grew. Whether they would change to flies, I cannot say. Another case is that of a horse of a friend, which was injured by accident and had to be killed. The animal was opened, and the walls of the stomach were found to be covered with the larvæ of the bot-fly. A piece of the stomach was spread on a board in the sun. Some turpentine was poured on the larvæ but with little effect, as not one was detached, when it was examined an hour afterward. Some whale-oil was poured on them. They let go immediately, and soon all died."

This subject of the tenacity of life in insects has lately engaged the attention of Belgian naturalist Plateau. We give his more important results. At the bottom of an open vessel holding a little over a quart of fresh water he placed a very small vessel containing the insect, and covered it with a piece of cotton netting. Terrestrial insects placed in these conditions, impelled by their specific lightness, rise to the lower surface of the net-work. The movements of their legs soon cease, they do not appear to suffer, and quickly grow torpid. The aquatic Coleoptera and Hemiptera, on the contrary, instead of submitting passively to their fate, endeavor to quit their prison swim rapidly about, try to come to the surface, and so struggle on till they are quite exhausted and lie at the bottom as if dead.

M. Plateau, after keeping the insects thus under water for a certain length of time, took them out and dried them on blotting-paper. He found that the terrestrial Coleoptera recovered after immersion in several instances, for 96 hours, while the aquatic swimming Coleoptera and Hemiptera had no such power of resistance to asphyxia. The author accounts for this by the rapid waste of oxygen caused by the greater activity of the aquatic insects. He also tried the effects of cold heat on the aquatic insects. It was found that these insects, in the latitude of Belgium can live for an indefinite period in water at the temperature of melting ice; but that they cannot remain alive in ice itself for half an hour. This he accounts for by the fact that in ice the insects are entirely deprived of all power of motion, thereby losing completely their animal heat. The author finds that the highest temperature which fresh-water spiders can endure, without injury, oscillates between 33°.5 and 46°.2 Cent. Comparing this with the results of experiments made on animals belonging to other groups, M. Platenu'a conclusion is, that the highest temperature endurable by aquatic vertebrates, articulates, and mollusks does not exceed 46° Centigrade.

Parthenogenesis in Shrimps—The Apus cancriformis or crab-shield shrimp has no less than 60 pairs of feet. each made up of an almost incredible number of joints.A German naturalist of the last century, Schaeffer, counted the joints in one of these animals and found them to number almost 2,000,000. Friedrich Brauer of the Vienna Academy of Sciences, has lately been studying the process of reproduction of these animals; and he finds that from the unfecundated eggs of the female spring females only, while the fecundated eggs produce only males. The experiments on the reproduction of the females extended over three generations. He also finds that the male Apus has one footless ring more than the female. With regard to parthenogenesis or the production of offspring with unfecundated eggs, C. Vogt, in the course of an address before the Swiss Society of Natural Science, stated that he observed in in another crustacean of the same order as the Apus, namely the Artemia salina, or brine-shrimp.

A Blood-sucking Squirrel.—Mr. Thomas G. Gentry recently reported to the Philadelphia Academy of Sciences the observation of a notable change of habit in a common red squirrel. Having had his attention called to the circumstance that the birds in a certain locality of Mount Airy were being rapidly killed off in the night-time, he found on going to the spot, that the author of the slaughter was a chickaree, or common red squirrel, which he caught in the very act of sucking the blood of one of its innocent victims. Mr. Gentry states that, with at most two exceptions, the Rodentia subsist principally or entirely upon vegetable matter, especially the hard parts of plants, such as nuts, bark, and roots; and he thinks that the taste for blood shown in this instance may have risen from the habit which some squirrels have of sucking the eggs of birds. "This adoption of another mode of life by S. Hudsonius, he thought a discovery of some note, as usurpation of habits leading to functional and structural changes in an animal’s economy is accounted as element of no mean weight in the development hypothesis, according tho the testimony of able writers upon Evolution."