Popular Science Monthly/Volume 31/June 1887/Popular Miscellany

From Wikisource
Jump to: navigation, search

POPULAR MISCELLANY.

Elective Studies in American Colleges.—Most of the leading colleges of the country, according to President Barnard, are admitting the elective principle more or less freely into their courses of study. In 1876 Yale College extended its very limited optional list from a minute fraction of the studies of the junior year to about one fourth of those of both junior and senior years. It was enlarged again last year, so that now, out of sixteen hours weekly, seven only are given to prescribed studies in the junior year, and three hours only in the senior. At Princeton one third of the time is given to prescribed studies in the junior year, and three hours in the senior. At Bowdoin about four fifths of the studies are prescribed during both junior and senior years. At the University of Pennsylvania and at Williams College the published announcements indicate that the time of the two later years of the course is about equally divided between prescribed and optional studies. At Rutgers it is allowed to elect one study during the junior and senior years. At Union one third of the time is given to elective studies during the senior year only; but this institution offers also elective courses, a classical and scientific course running through the entire four years. At Brown electives are offered as early as the sophomore year, when they occupy about one fifth of the time. In the same institution, in the junior year, they extend to one third, in the senior to about one half. At Amherst electives cover about one half the time during the second and third of the three terms of the sophomore year, and during the whole of the two later years. In the University of Michigan all the studies are elective after the close of the freshman year; and at Harvard University there are no prescribed studies at all.

 

Medicines and Digestion.—Dr. Robert G. Eccles lately called the attention of the Brooklyn Pathological Society to the importance of regarding the effect of medicines to be administered upon digestion. "We never stop," he says, "to question the wisdom of pouring into the stomachs of the sick, in the most promiscuous manner, drugs that inhibit or check the production of life- and health-giving peptone. In all chronic diseases, the paramount consideration is that of the patient's nutrition. Where we can not destroy the pathogenic micro-organisms outright, the patient's only hope in the struggle for life lies in the strength of his cells, and their power to triumph over their foes. The most important consideration at those times is digestion. To interfere with it, or check it, is in many cases criminal. When our remedies are incompatible with the gastric juice, the time of taking is likely to be of far more importance than the medicine itself. To weaken patients by the production of artificial mal-nutrition, gives their diseases the advantage over them, when a little more knowledge would have enabled us to aid the vital forces instead of handicapping them." The author described the properties of various remedies in this light, and gave accounts of a large number of experiments which he had made on the subject.

 

Coal-Tar Colors and Medicines.—Sir Henry Roscoe lately addressed the Royal Institute on "Recent Progress in the Coal-Tar Industry." He said that the hydrocarbons, the essential elements, or skeletons of all organic compounds, are classified as the paraffinoid—the bases of the fats—and the benzenoid hydrocarbons, which give rise to the essences or aromatic bodies, to which all the coal-tar colors, finer perfumes, and anti-pyretic medicines belong. The natural petroleum-oils consist almost entirely of paraffines, and are therefore commercially inapplicable for the production of colors. Coal may by suitable treatment be made to yield oils of a valuable character; and these products are now extensively obtained from the coal-tar which is a residue of the gas-making process, and of coking, when the conditions of temperature are properly managed. Even to enumerate the different chemical compounds which have been prepared during the last thirty years would be a serious task. To illustrate the amount of coloring-power concealed in coal, Sir Henry Roscoe presents tables showing that one pound of the mineral affords magenta enough to color 500 yards of flannel; aurine sufficient for 120 yards of flannel 27 inches wide; vermilline scarlet for 2,560 yards of flannel or alizarin for 255 yards of Turkey-red cloth. "We are at present acquainted, among the derivatives from coal-tar, with about sixteen distinct yellow colors, about twelve oranges, more than thirty reds, about fifteen blues, seven greens, and nine violets; and a number of browns and blacks, besides mixtures of the several chemical compounds, giving rise to an almost infinite number of shades and tones of color. These colors are capable of a rough arrangement according as they are originally derived from one or other of the hydrocarbons contained in the coal-tar. In the class called azo-colors, an azo or nitrogen group replaces the hydrogen in phenols and amido-compounds. They are chiefly bright scarlets, oranges, reds, and yellows, with a few blues and violets. Next in importance to the color industry comes the still more novel discovery of the synthetical production of antipyretic medicine. The initiative in the production of these compounds was given in the discovery by Professor Dewar, in 1881, that quinoline, their basis, is an aromatic compound; from it he obtained aniline. Kairine, the first of the antipyretics in the order of discovery, is manufactured from quinoline. It effects a remarkable lowering of the temperature of the body, which, however, is of much shorter duration than that effected by quinine; but, with the exception of its burning taste, it exerts no such evil effects as are often observed after the administration of large doses of quinine. Antipyrine, the second of these febrifuges, was discovered in 1883. It is made from aniline and aceto-acetic ether. As a febrifuge, it is superior in many respects to kairine and even to quinine. It equals kairine in the certainty of its action, while in its duration it resembles quinine. It is almost tasteless and odorless, is easily soluble in cold water, and takes the form of a white crystalline powder. Its use in medicine is accompanied by no drawback. A third artificial febrifuge is thalline, which is said to be used as an antidote for yellow fever. None of these substances are anti-periodics; and consequently they can not supplant quinine in cases of ague and intermittent fevers. Another group of coal-tar products comprises the artificial aromatic essences. Among these are cumarine, the principle of "new-mown hay"; vanilline, of vanilla, with its derivative vanillen, which is used in preparing "essence of heliotrope"; mirbane, a soap-perfume, and the artificial oil of bitter almonds. The most remarkable of all the coal-tar products is probably saccharine, a substance which surpasses sugar in sweetness. It is not a sugar, for it contains sulphur and nitrogen, nor does it act as a nutriment, but it is non-poisonous, and passes out of the body unchanged.

 

A Lesson in Practical Anthropology.—Sir C. W. Wilson, in a paper read in the British Association, on "The Wild Tribes of the Soudan," after describing the tribes and their clans, with their divisions and alliances, remarked that it was interesting to observe how thoroughly General Gordon had understood the situation in that region, and at once pointed out the remedy. When he left England, his instructions had been to proceed direct to Suakin, open up communication with the supreme sheik of the Hadendowas who had taken no part in the rebellion, and isolate and crush Osman Digma by raising against him the surrounding tribes, whose sheiks he knew personally. There can be little question that if this policy had been carried out early in 1884, before Sinkat fell and Baker Pasha had been defeated, it would have been successful. But, unfortunately, General Gordon's plans were changed and he proceeded up the Nile. Mr. Hyde Clarke congratulated the section on having had such a paper submitted to them, and said that Sir Charles Wilson had given them a useful exemplification of the value of anthropological studies. They had seen how incidents in the war in the Soudan had turned rather on the knowledge of the men than of the physical features of the country.

 

Photography of the Stars.—Professor Edward S. Holden has given, in the "Overland Monthly," a popular account of the methods and an estimate of the expectations of stellar photography. The photographic telescope requires special construction and arrangement of the lenses, which differentiate it from ordinary telescopes. If it is set fixed, the image of the star passing across the sensitive plate will leave a "trail," which is the visible representative of the direction of the star's diurnal motion. If arranged with a driving-clock, so as to follow the star in its motion, it will give a bright point, the photographic image. If we wish to make a picture of the sky, we must register the stars by such points as these. But the trails have various advantages, one of which it that they can not be mistaken for dust or for pin-holes on the plate itself; to avoid the liability to which, the dot-pictures are always repeated. The position of dots in latitude and longitude can be very accurately measured; the latitude of the star can be even better determined from its trail, but its longitude must be determined by special devices. The proper length of exposure for a star of the first magnitude is not more than 51000 of a second. For a star just visible to the naked eye, half a second is enough; for stars of the tenth magnitude, twenty seconds; of the twelfth, two minutes; of the thirteenth, five minutes; of the fourteenth, thirteen minutes; and for the faintest stars visible, an hour and twenty-three minutes.

 

Fire-Proof Mixtures.—The processes employed to make cloths and woods uninflammable ought to satisfy the following conditions: 1. The preservative substance or mixture should be cheap and easily used. 2. It should not change either the cloths or their colors. 3. It should not be poisonous or corrosive. 4. Cloths or woods impregnated with it should remain uninflammable after having been exposed for a month to a temperature of 100º and over. "La Nature" gives a few of the preparations which seem best to satisfy the different conditions required. A mixture applicable to all light fabrics consists of pure sulphate of ammonia, 8 kilogrammes; pure carbonate of ammonia, 2·5 kilogrammes; boric acid, 3 kilogrammes; pure borax, 2 kilogrammes; starch, 2 kilogrammes, or dextrine, or gelatine; water, 100 kilogrammes. Cloths should be dipped in the solution at a temperature of about 84º, till they have soaked it well up, then partly dried in the air, and afterward dried enough to be ironed like starched clothes. The quantity of starch, dextrine, or gelatine, may be varied according to the degree of stiffness it is desired to give the goods. This mixture is good for ball-dresses. A quart of it will serve for the preparation of about sixteen yards of goods. A mixture applicable to canvas that is already painted and to mounted scenery, to wood-work, furniture, curtains, bedclothes, cradles, doors, and windows, and which can be mixed with dyes, consists of sal-ammoniac, 15 kilogrammes; boric acid, 5 kilogrammes; glue, 50 kilogrammes; gelatine, l·5 kilogramme; water, 100 kilogrammes, with lime enough to give the proper consistency. It should be employed at a temperature of from 122º to 140º. The pieces may be dipped into it or painted with it. In case of decorations already painted it is enough to whitewash the backs of the canvases, and the frames on which they are hung, with the preparation. A kilogramme of it will paint five square metres of surfaces. A mixture applicable to heavier canvases, cordage, straw-work, wood, and carpentery, consists of sal-ammoniac, 15 kilogrammes; boric acid, 6 kilogrammes; borax, 5 kilogrammes; water, 100 kilogrammes. It is used at a temperature of 212º. The immersion should continue fifteen or twenty minutes, after which the piece should be aired and then dried. Another mixture is applicable to plain or printed papers. It consists of sulphate of ammonia, 8 kilogrammes; boric acid, 3 kilogrammes; borax, 2 kilogrammes; and water, 100 kilogrammes. It is used at a temperature of 122º. To resolve the problem completely—that is to reduce the action of heat on combustible articles to a simple calcination and render them uninflammable, and consequently incapable of starting or supporting a fire—the compositions should protect the fibers of the cloth or wood from contact with the air during the whole continuance of the heat; and the combustible gases disengaged by the heat should be mixed with so strong a portion of other, incombustible gases as to be no longer inflammable. Therefore, the cloth or the wood should be painted with a very fusible substance which, on the first impression of heat, will cover the surface of the fibers, adhere to them, and prevent the contact of the air. Salts that crumble under the action of heat, or of long-continued dryness, those that are hard to melt, efflorescing and hygrometric substances, are, therefore, not the most suitable for these applications. Borax and boric acid, which are included in the four receipts here given, are very fusible, and are not changed by heat, but only by an excess of moisture in the air, and well fulfill the first condition. Hydrochlorate, carbonate, and sulphate of ammonia readily give off incombustible gases, which have also the positive quality of extinguishing combustion, and thus admirably fulfill the other condition. Hence the compositions recommended possess all the desired qualities. They have also responded satisfactorily to varied tests of experiment.

 

A New African Region.—The Rev. David Asante, a native missionary of the Basle Gold Coast mission, Africa, recently visited during a journey of exploration the hill-country of Booso, where he says the temperature is cool, rains are frequent, and rivulets numerous. The country is thinly peopled by a population subject to goitre and extremely dirty, whose children and bachelors wear no clothing. Wives, being harder to get—by the process of wooing and winning their consent—than in most African countries are treated well. The fetich-worship is less subtile than on the coast, but the poison-ordeal is frequently resorted to, and accounts for the small population. When a person dies, a whole village sometimes submits to take an infusion of a poisonous bark. Quarrels are settled by resorting to the same dangerous arbiter, thefts are discovered by it, babies who cry much are made to swallow the infusion to prevent their growing up wicked, and parents who lose several children in succession take it in order that the cause of their affliction may be discovered.

 

Petroleum Products as Fuel.—The residues of the distillation of petroleum have been employed in the Caucasus for several years as a combustible, and have appreciated from having no value in 1874 till they command a price six times higher than crude naphtha, which is now employed as a cheaper fuel. Naphtha has been considered dangerous on account of its explosive qualities, but it has been found that they disappear when the liquid has been exposed to the air for a few days till it has lost its volatile constituents, which compose about fifteen per cent of its substance. Crude naphtha, right from the springs, is burned in the locomotive-furnaces of the Balachanskoi rail-road, and there are no accidents. Naphtha is the fuel that develops the greatest quantity of heat, and it also possesses the great advantage of not containing sulphur or other injurious substances. Ninety per cent of the theoretic calorific power can be realized from it, while not more than sixty per cent can be got from solid combustibles. In 1859, doubts were expressed in Russia as to whether petroleum could be used as a combustible; now it is employed exclusively on all the ships in the Caspian Sea, and only half as much of it is required as used to be consumed of coal. The maximum force to be obtained from petroleum is equivalent to two and a half times what coal will furnish; and experiments on the railroad from Baku to Balachan show that a given weight of naphtha will take the place of eight and a half times the weight of wood, although the theoretically calculated difference in calorific power is only as three to one. Petroleum is very conveniently introduced into the furnaces of locomotives with the injectors that are used; the combustion is very easily regulated, and the furnaces last well in the absence of sulphur, while no smoke, sparks, or ashes, are emitted.

 

Make Room for City Children.—Dr. James B. Russell, health-officer of Glasgow, while he admits that the moral delinquencies of parents, and particularly drunkenness, are important factors to the death-rate of children in cities, insists that too much influence should not be attributed to them. The child of sober, industrious parents, in a city of good sanitary conditions, still lacks room for his complete well-being. The element of space comprehends all the physical conditions of health so completely that the name density is recognized by vital statisticians as the best standard of comparative measurement. Then, as the child grows up, comes the natural desire for play and exercise, which is essential for health and growth. Pent up as city children are, their play becomes in great part mischief. The prevailing characteristics of children's play correspond with the manners, habits, and occupations of the adult population; thus, city children may very often be seen playing at being drunk, or at policemen and thieves, and at fighting. Nothing can be more pitiful than this compulsory perversion of a natural instinct into unwholesome ways. Among the best methods of recruiting city children, the author recommends the system of holiday "colonies," which is in vogue in several European countries. Selected, poor, weakly children, between the ages of seven and fourteen, are sent in colonies of from ten to forty each, under teachers, and the month constituting the school holiday is spent at farm-houses or school-houses in the open country. The improvement in health from these outings has been proved not to be temporary. Provisions for a similar purpose in some of the cities of the United States are commended. The laying out of cities needs to be modified with reference to the requirements of children. Wherever the element of space is involved in any proposed legislation, let the people support that which will give them the most space about their dwellings. They would save increased taxation in doctors' bills and burial expenses. They should remember that the most useful open spaces are those which are close to their houses. Distant parks are not substitutes for the occasional simple play-ground in the heart of the city. Both together form a provision for the young children as well as for the adults.

 

The Great Inland Depression of Brazil.—It is interesting, says Mr. J. W. Wells, in a paper on "The Physical Geography of Brazil," to note the great depression that extends through the center of the South American Continent, practically similar to what exists in the North American. A canoe can be navigated from the Rio Orinoco to the Rio Negro, thence to the Amazons, then up the Rios Madeira, Mamoré, Guaporé, and Alegré, where it will not be more than five or six hundred feet above the sea. It can then be hauled across a low, grassy flat, as is often done, to the Rio Agoapehy, and then descend by the Rio Jauru and Rio Paraguay to Buenos Ayres. The distance from the Amazons to the Plate by this route is about twenty-five hundred miles, of which sixteen hundred and fifty miles have already been traversed by steamers, leaving eight hundred and fifty miles to be navigated. But it must not be inferred that the whole of this route offers an almost uninterrupted course of navigable rivers; on the contrary, the remaining eight hundred and fifty miles that have not been explored by steamers, not only contain insurmountable obstacles to the passage of even the lightest-draught steamer, but in many places to even the ascent of a canoe. Yet this route will most probably be, in the more or less remote future, the main line of internal communication. By far the greater part of the lands of this natural way are as undeveloped as the Congo of Africa. A connection also exists between the Rio San Francisco and the Rio Tocantins. A canoe can leave the former river and go up the Rios Grande, Preto, and Sapão. The source of the last river is in a beautiful lake in a valley surrounded by fortress-looking table-topped hills; the margins of the lake are bordered by groves of grand Burity palms; on the west the lake drains out into a quick-flowing, considerable stream, the Rio Diego, joins a Rio Preto, and thence onward by the Rio do Sonno to the Tocantins. This journey could be made without once taking the canoe out of the water, except to descend with safety a few rough stretches on the western outlet of the lake.

 

The Gapes in Chickens.—Dr. H. D. Walker has contributed to the "Bulletin" of the Buffalo Society of Natural Sciences the result of the special investigations which he has made to determine the origin of the gape-worm (Syngamus trachealis) of fowls, lie believes it to be a parasite of the earth-worm (Lumbricus terrestris). Taking the opportunity of a prevalence of the gapes among the chickens, in 1883, and acting under the advice of Dr. Leidy, he sought for the Syngamus in the embryonic or larval condition, in some intermediate part. This might, he thought, be the earth-worm, the sow-bug (Oniscus asellus), or the garden-slug, all of which were found around the infected coops; while the coops that suffered most were near a bare spot of ground which was full of earth-worms. Parasites were found in the earth-worms and in the slugs. The three animals were fed separately to different chicks. No significant effect followed the feeding with slugs or sow-bugs, but the chicks fed with earth-worms developed symptoms of gapes. Experiments were made in artificial culture, and are described in the author's paper. For prevention of gapes, Dr. Walker recommends keeping the chickens away from the ground by putting them on floors, and destroying the earth-worm and its parasite by some preparation fatal to both, such as common salt; asafœtida and garlic, which have been relied upon to cure or prevent gapes, had no effect upon the Syngamus.

 

Dr. Bickerton's Experiments in Color-Blindness.—T. H. Bickerton, of the Royal Ophthalmic Hospital, Moorfields, has recorded the results of his personal examinations of 5,087 subjects, during five years, for color-blindness. Holmgren's tests were used. Of 3,087 men and boys tested, 179 failed at the first test (a very pale, pure green), either by omitting green, or by putting in some other color. Of these, 74 passed successfully the remaining tests, and were considered to have but a very slight chromatic defect, which might be disregarded. Rejecting these, there were 105 cases of color-blindness, or 3·40 per cent of the whole number. Of 1,841 women and girls examined, 3 only, or 0·162 per cent, were to a greater or less extent affected, and of these one so slightly affected that it was cast out, leaving 2 pronounced cases, or 0·108 per cent. Sixty-four male lunatics afforded 1 complete and 1 incomplete case, while 95 female lunatics were all correct. The social status of these and other persons examined varied from the lowest to the highest, and the ages ranged from five years upward. A large majority of them were under twenty-one. Besides those included under the head of very slightly color-blind, there were others whose color-perception was feeble. Among the lower social grades, as represented by the children in orphanages and reformatories, a considerable number made mistakes in the examinations, and these errors were made not only by those of dullish intellects, but also by those who, according to their mistresses, were sharp girls. Cases of this kind were retested after some months' tuition in colors, and in most instances, where ignorance was suspected, the second trial proved the correctness of that conclusion; but there were others who, although they fulfilled the test, did it with the utmost difficulty. Of the 105 cases of color-blindness, Dr. Bickerton further remarks: "Not one so affected was aware of the defect, and a number of them do not believe it to this day. It may seem curious that people who can not distinguish as different colors red, green, and brown, and in some few cases blue and yellow also, do not themselves discover their peculiarity in their vision for colors. Yet, strange as it may be, so it is, and you will find it exceptional for a color-blind to realize in the first instance the defect himself."

 

Effect of Climatic Changes on Species.—Any theory of the distribution of species, to be acceptable, must take account of the great gaps which appear in the extension of many kinds. Mr. Edward Forbes and many other modern botanists believe that the question is one of changes of climate; or that the climatic variations of the past are reflected in the fauna and flora of the present. Their views are partially confirmed by the observations which Professor A. Blytt, of the University of Christiania, has made of the climatological relations and the distribution of plants in Norway. Nearly all the climatological lines there run more or less in the shape of the coast, so that the climates are ranged in bands, the changes being observed as one goes from the interior toward the sea, or vice versa. In keeping with the same are the variations of the flora. The plants may be divided into groups, wherein the species belonging to the same group have a somewhat similar extension, while each of the groups is confined to special climatological conditions, and is found only in those parts where the conditions corresponding with its nature prevail. The flora is generally monotonous; but there are certain places dependent partly, perhaps, on the character of the soil, but as much upon exposure to the sun and protection from the changeableness of the coast climate, where a rich vegetation may be found. The flora is destitute of peculiarly characteristic species, because it has come to the country by immigration after the Glacial period, from other countries which were free from ice at that time. This immigration must have taken place during repeated changes of climate. "After several thousands of years with a severer climate that favored the immigration and extension of northern and eastern species, other thousands of years followed with a milder climate. During this period fresh immigrants came from the south and southwest, compelling the older flora to retreat. In this manner the climate must have changed several times since the Glacial age, and the distribution of the plants must have changed in accordance therewith. The periods of variation are reflected in the present flora, and it is the former which have led to the great gaps in the extension of coast as well as inland plants. The sunny screes, the slate districts, and the moist coast tracts, are asylums where the different floras have found refuge. In the intermediate parts they have been dislodged by the new-comers. But certain species, being indifferent to the variations, extended constantly, at the expense of others, and this is the reason of the Norwegian flora being so monotonous."

 

Artificial Digestion.—O. Petersen, of St. Petersburg, has made experiments to ascertain the influence of certain medicines on digestion. The problem he set himself to determine was the time required to digest from 20 to 40 grammes of dried albumen by the aid of 450 centigrammes of a specially prepared artificial gastric fluid. Alcohol in the proportion of five per cent did not hinder digestion, but the process was retarded as the percentage rose, and stopped at ten per cent of alcohol. Antipyrin, in light doses, was without influence, but in larger quantities slightly retarded the action. One or two grammes of bromide or iodide of potassium hindered the process a little. The organic preparations of iron scarcely affected the time required for the digestion, while reduced iron and the inorganic salts slowed the action, as did also magnesium and sodium sulphates, even in moderate doses. A gramme-dose of chloral hydrate had no slowing effect, though a marked retardation occurred with a dose of a gramme and a half. Chloride of sodium did not retard digestion, even when employed in large doses.