Popular Science Monthly/Volume 8/January 1876/Miscellany

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The Frailty of Modern Art.—The old masters made their own colors. The material which entered into their pigments came to them unadulterated, and the excellence of the paint depended on the brain mixed in it. Hence, their paintings to-day, though lacking somewhat freshness of color, have a mellowness which age can only give to pigments of the highest excellence. Modern pictures will not ripen, their colors fade, and the mellowness of the old masters is unattainable. Holman Hunt, of England, has called the attention of lovers of the fine arts to this deplorable fact. And the reasons are given. The artist's colors are no longer made by himself. Their manufacture is a business from whose secrets he is shut out. Artist's colors are subject to fearful adulteration. Even the oils cannot be genuine, as things go. The materials of which they are made go to the maker in a sophisticated state. Linseed and poppy-seed are adulterated before they reach the oil-maker's hands. So too, is it generally with the crude material for the pigments. A high-priced vermilion from an eminent dealer, upon analysis, yielded twelve per cent, of red lead. So the artist, who puts his whole life and soul into a painting that should be "a joy forever," has this immortality of art quenched by the use of dishonest paint.

Oscillations of Lakes.—The "seiches" of the lake of Geneva have for several years, as we learn from Nature been under investigation by Forel, of Lausanne. The term "seiche" is applied locally to certain oscillatory movements occasionally seen on the surface of the lake. The phenomenon had been investigated by previous observers, among them Saussure and Yaucher, who attributed it to variations in atmospheric pressure; in this, Forel agrees with them. The same phenomenon occurs in other Swiss lakes, and Forel believes it will be found in all large bodies of water. He recognizes in the "seiche" probably the most considerable and the grandest oscillatory movement which can be studied on the surface of the globe. His investigations have led him to the conclusion that the "seiche" on the Swiss lakes is an oscillatory undulation, having a true rhythm, and that the phenomenon is not occasional, but constant, though varying in degree. The duration of a "seiche" is a function of the length and depth of the section of the lake, along which it oscillates; this duration increases directly with the length, and inversely with the depth of the lake. The instrument he has devised for the investigation of the phenomenon he calls a plémyramàtre ("tide-measurer").

Contents of a Kitchen-Midden.—Prof. Cope lately exhibited to the Academy of Natural Sciences of Philadelphia a collection of animal remains, fragments of pottery, flint arrow-heads, etc., taken from an Indian kitchen-midden in Charles County, Md. The animal remains included the bones of seventeen species of vertebrata and two of shells. Of the vertebrates four were mammals, two birds, four reptiles, and seven fishes. The mammals were the Virginia deer, raccoon, gray squirrel, and opossum. Most of the deer-bones had been split into pieces lengthwise for the purpose of extracting the marrow. The birds were represented by a number of parts of the turkey, and the tarsometa-tarsus of some natatorial bird of the size of a widgeon. The reptiles were all turtles, and included the snapper, the box-tortoise, and two emydes. The fishes represented were the sturgeon and the gar, there were also numerous bones of Siluroid fishes of at least two species. The mollusks were Unio purpureus and Mesodon albolabris.

Habits of Blind Crawfish from Mammoth Cave.—In November, 1874, Prof F. W. Putnam collected a number of blind crawfish (Cambarus pellucidus) in the Mammoth Cave, which he kept alive for several months afterward in Massachusetts. The habits of these animals and the reproduction in them of lost parts are the subject of a communication by Prof. Putnam, published in the "Proceedings of the Boston Society of Natural History." The animals eat but very little in captivity. When food is dropped into the jar in which they are kept, they dart backward, then extend the antennæ, and stand as if on the alert. The animal continues in this attitude for several minutes, and then cautiously crawls about the jar with antennæ extended. On approaching the piece of meat, and before touching it, the animal gives a powerful backward jump and remains quiet for a while. It often repeats this three or four times before touching the food, and when it does touch it the result is another backward jump. When it has become satisfied that there is no danger, it takes the morsel in its claws and conveys it to its mouth. "I have twice," says the author, "seen the meat dropped as it was passed along the base of the antennæ, as if the sense of smell, or more delicate organs of touch seated at that point, were again the cause of alarming the animal. When the jaws once begin to work, the piece of meat, or bread, if very small, is devoured, but if too large, only a few bites are taken, and the food is dropped and not touched again."

A detailed account is given of one of the specimens, in order to show the mode of reproduction of lost members. This specimen, a female, was captured November 13th, being then perfect in all respects, except the right, large claw, which was as yet rudimentary. Total length of the animal from tip of large claw to end of tail, not quite two and a half inches. From November 14th to 24th, the crawfish lost in battle most of her antennæ, the third, fourth, and fifth legs from the left side, the fifth from the right side, and the two end-joints of the third leg on the right side; January 28th or 29th she cast her shell and came forth with a soft white covering, which was nearly two weeks in hardening. All the legs which were perfect before were now of the same size, but in addition the great claw of the right side was developed to about one-half or two-thirds the size of its fellow, and was apparently of as much use. The two missing joints of the third leg on the right side were also developed, though not quite to their full proportions. The fifth leg on the right side, and the third, fourth, and fifth of the left side, were reproduced, but in a very small and rudimentary manner. The antennæ were about two-thirds their full size. On April 20th the shell was again cast; the crawfish had now all the legs and claws nearly perfect. The great claw of the right side was very nearly as large as that of the left. The tip of the third leg of the same side was perfect, and all the legs that before were rudimentary were now developed apparently to their full proportionate size, with the exception of the last on the right side. Antennæ about full length.

From these observations, it will be seen that the parts are not reproduced in perfection on one shedding of the shell, but that each time the shell is cast they are more nearly perfect than before.

Sound and Fog Signals.—Among the papers read at the Philadelphia meeting of the American Academy of Sciences, was one by Prof. Henry on "Sound and Fog Signals," of which we present an abstract. The author stated the results of experiments made last summer, under the direction of the Lighthouse Board, at Block Island, and at Little Jail Island, at the east end of Long Island Sound. One set of experiments was made to investigate the cause of an echo apparently heard from the ocean: the results were not such as to solve the problem, though they favored the hypothesis that the echo was due rather to a reflection from the waves than from the air. Another set of experiments was directed to investigating the effect of elevation on the hearing of sound; the result was to show that a sound traveling against the wind is heard farther away on an elevation than at the sea-level. In five cases, sound was heard five times farther with the wind than against it, the wind's velocity being about five miles per hour. The effects of sound traveling with the wind, against it, at right angles to it, etc, were shown in diagrams representing curves of audition. In still air these curves are nearly circular; with wind uniform in velocity throughout the whole space the curves are approximately elliptical. The curves differed according to the different conditions. It appeared to be demonstrated that sound is heard farthest with a moderate wind, and that with a strong wind it is heard a less distance in every direction than in still air, and perhaps to a less distance than with a wind of moderate velocity. These experiments will be resumed next summer.

Origin of the Numerals.—Having never met with any explanation of the origin of the numerals, or rather of the figures symbolizing them, perhaps I am right in supposing that nothing satisfactory is known of it. In that case the following may be interesting to your readers: The first column contains the original figures, each containing

as many lines as the number which It is intended to represent. The other columns show the transitions likely to result from quick writing.—W. Donisthorpe in Nature.

Location of Sensory Centres in the Brain.—At the recent meeting of the British Medical Association, Dr. Brunton read a paper communicated by Dr. Ferrier, entitled "Abstract of Experiments on the Brains of Monkeys, with special reference to the Localization of Sensory Centres in the Convolutions." The experiments, which were conducted by trephining and the destruction of the sensory centres by means of a red-hot wire, led to the following results, as stated by the Lancet: These centres are bilateral, so that when, for instance, one of the centres of touch was destroyed, there was loss of tactile sensibility in the corresponding half of the body. Stimulation of the centre of hearing caused the animal to prick up its ears as if it heard something, while destruction of the whole of this centre rendered the creature totally deaf. Destruction of the centre of vision corresponding to one eye only, rendered the animal temporarily blind in that eye, the function, after twenty-four hours, being carried on by the opposite centre. In the discussion which followed. Dr. Nairne pointed out that other observers had arrived at conclusions different from those of Ferrier, and that the brain of a monkey could not be taken as exactly similar to that of a man; but Dr. Brunton thought the mistake made by German and other investigators who differed from Ferrier was, that they took the brains of animals lower even than the monkey to correspond with that of man. Dr. Dupuy said that he had found, when the centres of motion on one side of the brain were removed, that paralysis followed for a short time throughout the corresponding part of the body, but that, when the centres were removed from both sides of the brain, there was no paralysis at all.

Health of Children in Utah.—In a report made by Surgeon E. P. Vollum to the Surgeon-General on "Some Diseases of Utah," it is stated that the adult population of that Territory is as robust as any within the limits of the United States. The children furnish two-thirds of all the deaths, most of which occur under five years of age. In Salt Lake City, as appears from the register kept by the undertakers, the male deaths exceed the female in number about 50 per cent., but Surgeon Vollum could not get the relative proportion. The polygamous children are as healthy as the monogamous, and the proportion of deaths about the same, the difference being rather in favor of the former, who are generally, in the city especially, situated more comfortably as to residence, food, air, and clothing, their parents being in easier circumstances than those in monogamy. It is perhaps still too early to form an opinion as to the influence of polygamy on the health, or constitutional or mental character of the Anglo-Saxon race in Utah; but Surgeon Vollum has been unable to detect any difference in favor either of monogamy or polygamy. So far as he can learn, polygamy in Utah furnishes no idiocy, insanity, rickets, tubercles, struma, or debasing constitutional condition of any kind.

Vehicles of Infection.—A number of cases of the transmission of contagious diseases by means of clothing, articles of furniture, and other objects that had been in contact with persons stricken by such diseases, are brought together by a writer in Chambers's Journal, in order to show the great importance of thoroughly disinfecting such vehicles of infection, before making use of them again. The author, Mr, William Chambers, in the first place quotes Sir James Simpson's remedy for hospital-infection, namely, building such establishments of cast-iron, and casting them anew when contaminated. A servant-girl in Morayshire died of scarlet fever. Her clothing was sent back to her parents, but en route the box lay over for a few days at a railway-station. On reaching its destination, the contents of the box were dispersed among friends and neighbors. The children of the station-master, who had played around the box, and every recipient of the infected clothing, were stricken with the fever. Again, the clothing of a soldier who had died of cholera was sent home to his friends. While the garments were "in the wash," a man was employed on the roof of the cottage, repairing the thatch. He inhaled the poisonous fumes of the washing, and died of cholera. Scarlet fever of a malignant type appeared in a family at Carlisle, and two of the children died. In this case, the carrier of the infection was a retriever-pup, which had been reared in a house where scarlatina was present. It is stated in a pamphlet by Dr. McCall Anderson, of Glasgow, that a peculiar disease was introduced into a family in that town under the following circumstances: Some mice, caught in a trap, were seen to have on the head and front legs crusts of a sombre yellow tint, of circular form, and more or less elevated above the level of the neighboring healthy parts. A depression was noticed in the centre of each crust, and the parts where these had fallen off were ulcerated, and the skin appeared to be destroyed throughout the whole thickness. These mice were given to a cat, which soon exhibited, above the eye, a crust similar to those on the mice. Later still, two young children of the family who played with the cat were successively affected with the same disease, yellow crusts making their appearance on several parts of the body, on the shoulder, face, and thigh. Other instances are cited by Dr. Anderson, where mice, affected in the same way, had transmitted the disease to the human subject, both indirectly through cats, and directly through the mice themselves having been handled by children.

Practical Education.—A correspondent of the Moniteur Industriel Belge communicates to that journal a description of a school of practical instruction, situated in one of the suburbs of Paris. The writer exhibits to us a system of education in which the future occupations of the pupils are kept steadily in view, and where every step of progress in study marks an advance in real knowledge. A few instances will best show the method of instruction. Suppose a lesson in botany is to be given, and that the special subject is some textile plant. The pupil sees, in the botanic garden attached to the school, a few stalks of hemp growing. The botanic characters of the plant are explained to him; he is told how it grows, and what are the conditions favorable to its growth; then he is shown how it is treated in order to obtain the fibre, how the latter is spun, woven, etc. In giving instruction on minerals, a like course is followed. For instance, the subject is iron-ore: various kinds of ore are exhibited; the processes are explained, by means of models and designs, of the reduction of iron and its manufacture. So in mechanics: models of machinery are shown and explained; better still, the pupil is taken to the workshops where he sees various kinds of machines in operation. His understanding of things is tested by questions, and by being required to draw the objects he has been looking at, and to explain their working. Topography and geography are taught in the same commonsense way, the pupil being led to map out an ever-widening area. He begins with the plan of the school, then gives its relative position in the commune, in the canton, in the arrondissement, and so on. The great principle of instruction in this school is "to make knowledge concrete, practical."

Revivals and Religious Insanity.—In a paper by G. H. Savage, M.D., of the Bethlehem Hospital for the Insane, London, on "Religious Insanity and Religious Revivals," the lists of cases admitted to the hospital during the four months April to August, in the three years 1875, 1874, and 1873, are compared. The result does not show any increase of insanity traceable to the recent religious excitement in England. Indeed, the author sees no reason for regarding religious insanity as a peculiar, well-defined species of mental disease. According to him, it is simply an accident of education, temperament, or sex, whether certain subjective feelings develop themselves into a morbid religious idea, or into an illusion of being persecuted and annoyed by others. "Many persons," he adds, "verging on insanity—in fact, in the melancholy stage of the disease—seek religious consolation, and, not-withstanding this, go mad; they would probably have gone mad in any case, and the most that can be said against the service is that it precipitated the attack." But to return to the figures. In 1875, from April to August, there were admitted to Bethlehem 42 male patients, and of these 9 suffered from religious insanity. During the same time 55 women were admitted, of whom 8 had religious delusions. That was 21.4 per cent, of the men, and 14.5 percent, of the women. During 1874, in the same period, 30 male admissions gave 6 religious cases, and 47 female cases gave 16 that is, 16.6 and 34 per cent, respectively. In 1873, 28 male admissions gave 4 religious cases, or 14.2 per cent.; 28 female admissions gave 8 religious cases, or 28.4 per cent.