# Popular Science Monthly/Volume 31/October 1887/Popular Miscellany

Layout 4
POPULAR MISCELLANY.
Economy of Food.—In his American Association paper on "Economy of Food," Professor L. O. Atwater laid down the principle that "the cheapest food is that which furnishes the actually nutritive materials at least cost." The nutriments of vegetable food are, he said, in general much less costly than the animal foods. The animal foods have, however, the advantages of containing larger proportions of protein and of fats, and the protein at least in more digestible forms. Flour, meal, and other staple vegetable foods, furnish the nutriments at only a fraction of their cost in ordinary animal foods. At market prices, current in the Eastern States, the cost of the protein ranges at from eight to thirty-four cents a pound in the staple vegetable foods, and from eighteen cents to somewhat over one dollar a pound in the staple animal foods. In oysters it ranges at from two to three dollars a pound, in salmon sometimes to five dollars a pound, in beef at from ten to twenty-five cents a pound from about forty cents to one dollar and ten cents. In many of the usual food-fishes the nutritive material is dearer than in beef. The less expensive kinds of meat contain as much nutriment as the costlier kind; and the different grades of flour have a much more nearly equal nutritive value than is commonly supposed. Among the vegetable foods, wheat-flour, corn-meal, and other cereal products are in general the cheapest and most economical. Wheat flour at six dollars a barrel and potatoes at forty cents a bushel would furnish nutritive material at about the same cost. The prices of the choicer food-materials are regulated by flavor as well as by the amount of nutritive material, which in some is hardly a fraction of the price. With exceptions that are easily explained, the prices of foods that are bought and used for their nutriment tend to shape themselves proportionately according to the actual values. Taking the world through, the mass of people select those foods which furnish the actual nutrients at the lowest cost; but there are marked exceptions in the United States, where many, even among those who desire to economize, use needlessly expensive kinds of food. "They too often endeavor to make their diet attractive by paying high prices in the market rather than by skillful cooking and tasteful serving at home." Wastefulness of food shows itself in the purchasing of more than is needed; in using part of the excess to overload the alimentary organs and throwing the rest away; in purchasing food that seems cheap but is really dear; in using costly materials where less expensive ones would serve as well; and in the false economy of using too little of one material and too much of another. Great evils accrue from these practices, in the loss of money and the deterioration of health; and "some of the wisest students of physiology and hygiene are persuaded that improper eating, and especially overeating, is a source of more disease than any other one thing."
Clothes-Moths.—Clothes-moths, injurious to woolen goods and furs, are of the species of Tinea—pellionella, biselliella, tapetzella, or rustica. The most common one is Tinea pellionella, which in its mature state carries about half an inch expanse of wings. Its fore-wings are shining, grayish-yellow, with three indistinct brownish spots in the middle, and its hind-wings are whitish-gray. It is abundant in houses, and may be found at any time between January and October, though most abundantly in the early summer months. The moth is innocent. The larva, which does all the damage, is a tiny caterpillar, dull whitish, with a reddish-brown head. It is the only one of the four species that makes a tunic or movable case for itself. This case is very ingeniously constructed, and consists of an outer layer of fragments of the articles it has fed upon, and an inner layer of silk, forming a soft and smooth lining. It is nearly cylindrical in form, but of slightly larger diameter across the middle, and a little flattened above, and it is open at both ends. These cases are varied in their appearance, and of different colors, according to the color of the goods from which they are formed. The case is enlarged as the insect grows, both by adding to its length and to its circumference. For the latter enlargement, the case is split and patched up in two slits at each end, with an ingenuity that borders on intelligence. The chrysalis state is assumed inside of the case, the caterpillar becoming, by throwing off its last larval skin, a little, yellowish-brown, helpless thing, similar in form to the chrysalides of the larger moths. The chrysalis is anchored by fine threads to the cloth in which the insect lives. From this the perfect insect emerges, when its time has been fulfilled, lays its eggs, and then dies. The eggs are extremely minute, and are deposited on the cloth, or in crevices and corners close to a supply of food. The young grubs begin life by attacking the old cases of their progenitors, with which they make cases for themselves, and begin to feed on cloths proper at a later period of life.
Polished Objects of Silicified Wood.—Mr. George F. Kunz, in exhibiting before the American Association polished specimens of jasperized and agatized woods from Arizona, referred to the description of these woods which he had published in the "Monthly" for March, 1886, their magnificent ​colors, and their capacity, on account of the large sections which they would afford, to furnish art-objects of unexampled qualities. Although it was thought that sections two or three feet in diameter might be produced, it has until very recently not been possible to get such sections polished. At last machinery was found competent to do the work; and Mr. Kunz was able to show some beautiful large specimens, which had been cut by a gang of seven saws and polished at Sioux Falls, Dakota, by water-power from the falls, on wheels fourteen feet in diameter. The objects exhibited included one column eleven and a quarter inches wide and twenty-one inches high, cut transversely across the tree so that the heart was visible on two sides of it, with the radiations in all directions; also five sections, measuring twenty-five, nineteen and a half, twenty-four, seventeen and a half, and thirteen inches in diameter, respectively, so highly polished that, when turned with the back to the light, they formed a perfect mirror. All of the specimens were brilliant in color.
Telephonic Communication between Ships.—Professor Lucien E. Blake described in the American Association a method which he had conceived in 1883 for making telephonic communication between ships at sea. A sound-producing apparatus was to be attached to each vessel, and to be worked under the surface of the water; and each vessel was also to have a sound-receiving apparatus, to take up the signals from other vessels. Signals, intelligible by means of a code, could be produced by this apparatus, which would be transmitted in all directions through the water with a velocity four or five times that in the air. For steamships the sound-producing apparatus was designed to be a steam fog-horn or whistle, specially constructed to sound under water, and to be heard at least six or eight miles off. With such whistles, a Morse alphabet, of long and short blasts and pauses, was to provide a means of extended communication, while a simple universal code would indicate a ship's course. Since ignorance of the very presence of a ship, rather than incorrect estimates of her course, has been the principal cause of ocean collisions, the simple hearing of the sound would prove a most excellent general safeguard. Bell-buoys were to have a second bell added under water, while lightships, lighthouses, and any headlands might also be provided with submerged bells, which could be rung from the shore when necessary. Sailing-craft would also have bells, which, if like ordinary locomotive-bells, could be heard at least two miles under water. By the method described, in October, 1885, signals were transmitted and received through one and a half mile in the Wabash River from a locomotive-bell, around three or four windings of the stream.
Teaching Physics in the Public Schools.—Professor W. A. Anthony, speaking in the American Association, Section of Physics, on the importance of teaching physical science in the public schools, said that proper scientific instruction in the primary schools would teach children to avoid the mistake of attempting the impossible. While grammar should be put off to the last, language should be taught by reading, not by rules; the geography, after teaching the form of the earth, should be used only as a book of reference; and the commercial departments of arithmetic should be relegated to the business-school; children in their earliest experiences have to do with heat, light, sound, movement, and magnetism. Physics should be taught by calling attention to familiar facts, and then explaining them.
Effect of Light on Bacteria and other Organisms.—Messrs. Downes and Blunt, in two papers read before the Royal Society in 1877 and 1878 on the effect of light on bacteria and other organisms, and on protoplasm, announced the conclusion that light is inimical to these organisms, and under favorable circumstances may wholly prevent their development. The effect was shown to be due to oxidation, which was stimulated by light, and ended in the extinction or in the great depression of the vitality of the organisms submitted to it. The authors furthermore declared that the maximum of the oxidizing effect was near the violet, or in the more refrangible rays, and was comparable with the chemical phenomena of ​photography. When we come to the other end of the spectrum, the yellow and red, or more refrangible rays, we find that they promote the formation of chlorophyl and so turn vegetation exposed to them green, favoring the growth of green plants. In this we may discover one of the purposes which chlorophyl fills—as that of a special coloring-matter to the plant to filter out the more injurious rays and protect the delicate protoplasmic cell-contents from their destructive action.
Healthy and Unhealthy Occupations.—The English Registrar-General has made a comparison between healthy and unhealthy occupations. Assuming the normal average death-rate of the community as the unit of comparison, and calling it 1,000, particular occupations may be regarded as healthy or unhealthy according as the death-rates among those pursuing them fall above or below that figure. The most healthy occupation appears to be that of ministers of religion, whose rate is 556. Next are gardeners and nurserymen, 599; farmers and graziers, 631; agricultural laborers, 701; schoolmasters, 719; and grocers, coal-merchants, paper, lace, and hosiery manufacturers, wheelwrights, ship-builders and coal-miners, with all of whom the average death-rate is under 775. The most unhealthy occupations are the trades connected with the liquor-traffic and hotel service, with which the death-rate is 2,205; following these are general laborers in London, 2,020; costermongers, bankers, and street sellers, 1,879; innkeepers, etc., 1,521; and brewers, 1,361. After the trades concerned with alcohol, the highest rates are furnished by occupations that involve the breathing of dust other than coal-dust and exposure to lead-poisoning. The death-rate among butchers is also high, 1,170.
Cause of Thunder.—M. Him explains thunder and the explosive noise of meteorites by observing that the air traversed by an electric spark—that is, a flash of lightning—is suddenly raised to a very high temperature, and has its volume considerably increased. The column of gas thus suddenly heated and expanded is sometimes several miles long; as the duration of the flash is not even a millionth of a second, it follows that the noise bursts forth at once from the whole column; but for an observer in any given place, it begins when the lightning is at the least distance. In precise terms, the beginning of the thunder-clap gives us the minimum distance of the lightning, and its duration the length of the column. The author points out that a bullet whistles in traversing the air, so that we can to a certain extent follow its flight; the same thing happens with a falling meteorite just before striking the earth. The noise actually heard has been compared to the flight of wild geese, or to the sound produced when one tears linen; it is due to the fact that the air, rapidly pushed on one side in front of the projectile, whether bullet or meteorite, quickly rushes back to fill the gap left in the rear. The velocity of the meteorite is so great that the matter on its surface will be torn away by the violence of the gaseous friction produced, and will be vaporized at the same time by the heat. This is undoubtedly the origin of the smoke which meteorites leave trailing behind them. With this velocity the sound following the meteorite is vastly deeper and more like thunder than that which attends the passage of the relatively slow-going bullet.
Prehistoric Chronology of America.—Dr. D. G. Brinton, Vice-President of the Anthropological Section of the American Association, gave there a "Review of the Data for the Study of the Prehistoric Chronology of America." The resemblances between American legends and Oriental myths were considered accidental. The annals of the Mexicans, the Mayas of Yucatan, and the Quichas of Peru, carry us back hardly more than five hundred years. The recollections of the more savage tribes did not extend back more than two centuries. A calm weighing of the testimony respecting the stone buildings of Mexico, Yucatan, and Peru, places them all well within our own era, and most of them within a few centuries of the discovery. The much more ancient artificial shell-heaps along the coasts furnish data to prove that the land was inhabited several thousand years ago. The industrial activity of man in America may be traced by the remains of his weapons, ornaments, and tools, ​made of stone, bone, and shell. Specimens of polished stone and pottery testify to a reasonably-developed skill; but in the Trenton gravels and a few other localities, genuine palæolithic remains have been found, putting man in America at a date coeval with the close of the Glacial epoch, if not earlier. Vast antiquity is further proved by the extensive dissemination of maize and tobacco, and by the existence of about two hundred radically different languages, both of which must have required long periods of time in development. The American race is distinctively a race by itself, and appears so in the oldest crania from the Quaternary.
The Food of American Workmen.—In his American Association paper on "Food of Workingmen and its Relations to Work Done," Professor L. O. Atwater said that statistics of the dietaries of considerable numbers of Americans, mostly of the working-classes, show that their food is ample in amount, and includes large proportions of meat. Chemical examinations of the dietaries showed them to be richer in actual nutritive material and potential energy than even the large quantities would imply. This is because they contain so great proportions of meat and other nitrogenous and fatty substances. Comparing the standard of diet prevailing among the workingmen of Massachusetts with that of Germany, it is shown that laborers in Massachusetts average just about one half more than the German standard requires. It thus appears that the food of the American laboring-man is much more nutritious on the average than that of his European competitors. It is also shown that he turns off much more work than the European workingman. He is better paid, better housed, better clothed, and better fed than the European. He has better opportunities for self-development, more to stimulate his ambition, and more hope of reward if his work is efficient. These factors are all connected, but the explanation of his superior capacity for work is to be found largely in his superior nourishment.
Optimistic and Pessimistic Diseases.—Dr. Charles Porter Hart read a paper in the American Association "On the Correction of Certain Mental and Bodily Conditions in Man," the burden of which was to indicate that diseases located above the diaphragm are optimistic in their tendencies, while those below the diaphragm are pessimistic. His attention was first called to the subject by a patient who, suffering from an abdominal disease which seemed to produce a mental aberration, possessed most decidedly pessimistic views. Upon every subject that could be suggested—social, governmental, or religious—his views were of a markedly gloomy character. According to the table of disease-tendencies which the author has constructed, chest-diseases give buoyancy to the system, abdominal diseases are depressing, and diseases of a constitutional and chronic character, like rheumatism, malaria, and dropsy, are equally pessimistic and optimistic.
The Physical Aspect of Economics.—Mr. P. Geddes, in a British Association paper on "The Physical Aspect of Economics," said that the present isolation of economic from physical and biological studies, in spite of the clear dependence of the social sciences on the preliminary one, was to be accounted for, not on rational but simply on temporary grounds—that of the pressure of detailed labor upon every specialist. Yet, the sciences were needed on every hand. The population question was a strictly biological one. So, too, was that of competition, and even of individualism versus socialism, which largely came down to a dispute between the advocates of natural and artificial selection respectively. The popular idea of progress, as lying essentially in the quantity of wealth and in the number of population, needed thorough replacement of the scientific one—that of the improved average individual quality of the organisms composing the society, and of the material surroundings upon which their evolution depended.
The Falls of the Orange River.—Mr. G. A. Farini, who has recently made a journey across the Kalahari Desert in South Africa, succeeded in seeing and photographing the falls of the Orange River, which he was told could not be done. "We had," he says, "to swim rapids, climb rocks, and descend precipices by ropes in order to take the views. The river is broken up into many streams by huge rocks and bowlders, some of them rejoining to form the main ​waterfall, and others cutting out separate channels to the great gorge, some four hundred feet deep and sixteen miles long, worn in the solid granite. These streams form many rapids, and, when the river is half full, rise and form over a hundred separate cascades, unsurpassed for beauty and picturesque grandeur. When the river is full, many of them join to make one mighty sheet of water, rivaling the great Niagara, as it pours into the abyss nearly four hundred feet below. At low water, the only time it can be approached, the Hercules Fall is one hundred and sixty-five feet high, with several smaller falls at the sides, which are three hundred and fifty feet high, and are caused by the same water before it reaches the main fall."