Popular Science Monthly/Volume 14/March 1879/Popular Miscellany


Printing and the Perpetuity of Modern Civilizations.—The subjoined remarks on the influence of printing on the permanency of our modern civilizations are from the able address delivered in August last before the American Association for the Advancement of Science, by Professor A. R. Grote, Vice-President of Section B:

Those who have brought together the story of the ancient civilization of Greece have agreed with unanimity that the separation between the mass of the people and the intellectual portion became at length insurmountable, and finally led to national destruction. This makes for our own view, that it was to a defect or incompleteness in the machinery for the dissemination of knowledge that we must ascribe the dying out of the older states. An intellectual aristocracy was established in Greece, which, in order to maintain its superior position, and thus, from natural and selfish motives, endeavored to prevent the spreading of new facts, but it was assisted in this action by the limitations which an ignorance of the art of mechanically duplicating writing threw around it. Philosophers have explained the fall of Greece, by considering it as a necessary step in the progress of humanity and the perfection of a future bloom of knowledge. And so in one sense it may be; but still exactly where the defect lay, and where there is a positive advantage in the conditions of modern civilization, and wherein modern civilization more adequately protects the state, have sometimes escaped them. To understand this fully we must come back to natural history, to anthropology, at last. A large class of persons with a certain bias persistently decry our modern civilization, and look for its more or less speedy evanishment, merely because Rome perished and Greece decayed. But nowhere in nature is there exact repetition, and to understand the new civilization we must remember that it rests on a larger average intelligence, brought directly about by the discovery of the art of printing. There is then a distinct reason, a scientific ground, for the opinion that our present civilization rests upon a surer basis than did those which preceded it, and this we may safely bring forward in the cause of truth. For science is in danger always of being regarded as the enemy of the state, because it tends constantly to modify existing ideas. But if we can show the necessity for a constant modification of our ideas, arising out of our own constitution, then it may be seen to be unreasonable to defame those who follow the search for truth. And it being undoubtedly true, as Locke says, that, of all the men we meet with, nine out of ten are what they are, good or evil, useful or not, by their education, we can see how wide-reaching the effect of our improved basis of civilization must be upon us as a people, and how important it is to understand the real direction in which it works.

The Causes of Ocean-Currents.—An important contribution to the theory of ocean currents is made by Professor Zöppritz, of the University of Giessen, who aims to show that these currents are produced by the impulsion of the winds. As Mr. Croll observes, in bringing Zöppritz's paper under the notice of English readers in "Nature," one of the main objections urged against this theory is that the winds can produce only a surface movement, while many of the ocean-currents extend to great depths. The reply to this objection is, that if the surface waters be impelled forward with a constant velocity by the wind or any other cause, they will drag along with themselves, though with a velocity somewhat less, the layer immediately below themselves. This second stratum now exerts the same influence on a third adjoining stratum, and sets it in motion in the same direction. The third stratum, in like manner, draws with itself a fourth, and so on. The propagation of this velocity is only bounded by the limits of the fluid itself. If these limits consist of a solid plane parallel to the strata, then the propagation of the velocity will cease only at that point, i. e., between the last liquid stratum and the first solid stratum. Among the results found, the author lays particular emphasis on two: "In the first place, the steady motion arising in the interior of an unlimited stratum of water from an unvarying surface velocity makes itself felt with linearly decreasing velocity down to the bottom. Hitherto the view frequently expressed was, that the influence of surface currents reached only to very moderate depths. Secondly, it was found that all variations according to time, whether periodic or aperiodic, of the forces acting on the surface, propagate themselves downward with extraordinary slowness, the periodic in very quickly decreasing amount. Taking both statements together, it follows that the movement of the chief part of the stratum of water exposed to periodically varying surface forces is determined by the mean velocity of the surface, and that the periodic variations are observable only in a comparatively thin surface stratum."

Population-Density and Rates of Mortality.—Some curious and interesting results are developed by Dr. Farr, F. R. S., from a study of the rate of mortality in connection with statistics of population-density. He finds that the rate of mortality increases as density of population increases, and this he proves by arranging the 619 districts of England and Wales in groups according to the rates of mortality, and showing that all the groups follow this law. Thus in the ten years 1861-’70, at one end of the scale the deaths per 1,000 of population are 15, 16, and 17; at the other end, 31, 33, and 39. The acres per capita in the corresponding districts are 12, 4, and 3, and 1·01, ·05, 1·01. The intermediate rates of mortality are 18, 19, 20, 21, 22, 23, 24, and 25, while the acres per capita are 4, 3·3, 2·9, 2·1, 1·1, ·05, and ·02. Now, excluding the London districts, about which there is some difficulty, we have 7 groups of districts where the mortality ranges thus: 17, 19, 22, 25, 28, 32, and 39. In the same districts the number of persons to a square mile is 166, 186, 379, 1,718, 4,499, 12,351, and 63,823. Thus, in Liverpool, the densest and the unhealthiest district in England, there were 63,823 to an acre; of whom 39 per 1,000 died annually. This series of facts may be put in a different way; The nearer people live to each other the shorter their lives are. Thus the proximity of people in 53 districts is 147 yards, the mean duration of life is 51 years; in 345 districts the proximity is 139 yards, and the mean duration of life is 45 years; in 137 districts the proximity is 97 yards, and the mean duration of life is 40 years; in 47 districts the proximity is 46 yards, and the mean duration of life is 35 years; in 9 districts the proximity is 28 yards, the mean duration of life is 32 years. In Manchester district the proximity is 17 yards, and the mean duration of life is 29 years; in Liverpool district the proximity is 7 yards, and the mean duration of life is 26 years. This is a determined law, and, the duration of life being given in one set of conditions, the duration of life in another set of conditions is determined from the proximities.

An Interesting Collection of South American Fossils.—Prof. Cope bought the collection of fossil bones from the Argentine Confederation which were brought to show at the Paris Exposition. Several countries are said to have wanted them. They will be of value in this country, because the chief portion of them are not to be found anywhere in the United States. They come from Patagonia, and the collection includes about one hundred and fifty specimens of animals. There are nineteen skeletons, chiefly of large animals, almost completely whole, among which are armadilloes and sloths. One of the armadilloes has a curious tail which increases in size toward the end, at which point it takes an oval shape and is from a foot to eighteen inches wide. Unlike that of all other armadilloes, it is without joints, except that at the base. It is supposed to have been a fighting weapon. Another rare specimen is a sabre-toothed tiger, of which there is only one other known specimen in the world. The size of the sloth skeletons varies from that of a small black bear to the largest elephant. The sabre-toothed tiger and the club-tailed armadillo are supposed to have been monarchs of the forests in their day. It has not yet been determined to what institution of science the collection is to be presented.

Artificial Diamonds.—In examining the papers of their deceased father, J. N. Gaunal, Messrs. A. and F. Gaunal found one which purported to be a copy of a memoir presented by him to the Paris Academy of Sciences in 1828, and which gave an account of a process for the artificial production of diamonds. The Academy simply buried the communication in its archives, and never mentioned it in any way. The substance of this document is now published in "Le Monde de Science et de l'Industrie," from which we take the following particulars: Equal weights of carbon sulphide and of phosphorus, both as pure as possible, are put in a flask, and a little water added which floats on the top and prevents the sulphide from turning to vapor and from taking fire. The whole having been placed in some situation where it will not be disturbed, the sulphur of the sulphides combines with the phosphorus and releases the carbon, which falls to the bottom and assumes a crystalline form. This result takes place slowly, and not till after the lapse of six months was M. Gaunal able to obtain diamonds the size of a grain of millet-seed. As for the purity of these small diamonds it was proved by the strictest tests, and that not only by M. Gaunal but also by others. The experiment was repeated several times in the course of many years by M. Gaunal, and always with the same result. The artificial diamonds consist of pure carbon in dodecahedral crystals, and they scratch steel like the natural diamond.

Protection of Iron Surfaces from Rust.—We have already briefly described Professor Barff's method of rendering the surface of iron unoxidizable, yet, by way of introducing some remarks on the results of the process published in the "Lancet," we may repeat that it consists merely in subjecting the iron to the action of superheated steam—steam having a temperature of 1500° Fahr. This steam is generated in an upright boiler, and is then conducted through the "superheater," which imparts to it the necessary temperature. The iron articles to be acted on are placed in a chamber built of fire-clay, and the steam being admitted to it a coating of magnetic, or black, oxide of iron is produced on the surface. And now for the result. The article has a dull black appearance, and is susceptible of a high degree of polish. The surface coating is absolutely adherent, and is so hard that it is not removable by ordinary methods, for instance, an iron rasp has no effect on it; and the same is to be said of all the agents which under ordinary conditions oxidize iron. Salt or fresh water, vegetable acids, and even the London atmosphere, are unable to produce the slightest tarnish. Iron vessels which have contained water for weeks are entirely free from rust. Iron piping and ornamental castings, which have for months lain among the wet leaves in the garden outside Professor Barff’s laboratory, are unchanged. The cost of the process is trifling, less than that of "galvanizing." The sanitary and domestic uses of iron thus prepared are numerous, as for water-pipes and cisterns and for cooking apparatus.

Plants and Atmospheric Humidity.—Two questions of considerable interest, viz., that of the effect of living plants on the atmosphere of houses and that of the relations between forests and atmospheric humidity, appear to have no little light thrown upon them by the ingenious researches of Dr. J. M. Anders, published in the "American Naturalist." We can not state with any degree of fullness the author's experiments to determine the amount of vapor transpired by plants in proportion to the area of their leaf surface. Suffice it to say that according to these experiments the "Washington elm," at Cambridge, Massachusetts, with its 200,000 square feet of leaf surface, would transpire seven and three quarter tons of watery vapor in twelve diurnal hours of clear weather. Carrying the calculation further, a grove consisting of 500 trees, each with a leaf surface equal to that of the elm mentioned, would return to the atmosphere 3,875 tons of aqueous vapor in twelve hours. In-doors, transpiration is during the day only about one half as active as in the open air, but at night it is about equal in the two situations: hence the transpiration of a plant in-doors is more than one half as much in twenty-four hours as it would be outside. It follows that growing plants increase the humidity of the atmosphere in a closed room. This point is very important where rooms are heated by hot air furnaces. In such apartments the air is drier than in apartments heated by a stove or an open fireplace. In a dry atmosphere of the temperature of 65° to 68° Fahr. a great demand is made upon the system to supply the air with moisture, the skin and pulmonary mucous membrane are dried, and a condition is induced which is expressed in irritability of the nervous system, paleness and susceptibility of the skin to cold, liability to pulmonary diseases, and, in short, deterioration of all the functions. Now, if the presence of a certain number of thrifty plants in an occupied apartment, warmed by dry air, would have the effect of raising the proportion of aqueous vapor, it is clear that plants in rooms heated by a hot-air furnace would, in an hygienic point of view, be of very decided value, since they may become the means of obviating very distressing symptoms, or even disease itself. As for the question of the relation of forest growth to atmospheric humidity and consequently to rainfall, such relation would appear to be clearly established by the author's researches.

Source of Organic Matter in Igneous Rocks.—Associated with the sheet of trap-rock which forms the First Newark Mountain, New Jersey, there occurs near Plainfield an amygdaloid trap passing into a metamorphosed shale. Many of the cavities in the amygdaloid rock are filled with a jet black carbonaceous mineral, closely resembling the "albertite" of New Brunswick. Above the amygdaloid is a metamorphosed shale, traversed by seams and fissures, which are frequently filled with the same albertite like mineral. Finally, resting on these metamorphosed beds are slates, shales, and sandstones, which contain fossil fishes and an abundance of obscure vegetal remains. From this state of facts Mr. J. C. Russell ("American Journal of Science" for August) infers that the organic bodies in the uppermost strata furnished by their decomposition the carbonaceous material in the associated rocks, the heat derived from the slowly-cooling injected rocks playing an important part in this process. Similar deposits of carbonaceous mineral in igneous rocks are found in other localities, as at Cape Gaspé, and in the lava of Mount Etna, though in these cases it occurs in the less concentrated form of mineral oil. But Mr. Russell sees in these different forces only different stages of one and the same process. "If," he writes, "the cavities of a rock were filled with petroleum by infiltration, and evaporation slowly removed the more volatile portions, and oxidation took place to some extent, the result would be the formation of a deposit of solid hydrocarbon in the cavities. A similar process sometimes occurs with bottled samples of petroleum, by which the interior of the bottle is left coated with a solid carbonaceous layer. In the rocks, if a fresh supply of oil were furnished from time to time by infiltration, the cavities would eventually become completely filled with the solid carbonaceous residue. A vesicular lava might in this manner be changed to an amygdaloid, the cavities of which would be filled with solid hydrocarbons instead of quartz, zeolites, etc. Such, it appears to us, must have been the history of the Triassic amygdaloid we have described, the cavities of which must at one time have been filled with mineral oil. This is but an epitome of what took place on a grand scale at the great fissure, over 1,400 feet deep, in New Brunswick, which was filled with albertite, and in the case of the Grahamite in West Virginia, which also occupies an immense fissure."

Whence came the Arctic Mammoth?—Were the mammoths whose remains are found in the north of Siberia native in that region, or were they carried thither by rivers from a more genial climate? If the latter supposition were correct, we should find the remains only in the vicinity of the great watercourses, while, in fact, they occur in localities distant from the beds of streams. But here fresh difficulties face us, for, though the mammoth was covered with a thick coat of long hair, how could it live in a region where the temperature in Januuary is as low as 65° Fahr., where the summer lasts only three or four months, and where the vegetation is exceedingly scanty? The supposition is plainly inadmissible, and hence either we must believe these remains to have been transported hither, or else that in early times the climate of Siberia was much less severe than it is at present. Nor is this a baseless theory, for, as Mr. U. H. Howorth observes, the plants found in the fissures of the rhinoceros-teeth (contemporary with the mammoth) are those which now live in southern Siberia. The plant-remains associated with the mammoth (not floated from a distance, but of the locality) show the same thing, the species being larch, birch, and other trees of good size. Other evidences of the existence of a higher mean temperature in Siberia at the time of the mammoth are found in the fresh-water and land shells associated with the remains, but now extinct in northern Siberia. As for the manner of the mammoth's extinction, Mr. Howorth believes it to have been sudden. The remains must have been preserved soon after death. They were destroyed by a flood due to some sudden convulsion, which also changed the climate.

Civilization and Teeth.—From the study of 1,249 skulls, of which 844 represent modern highly civilized races, and 277 modern inferior races, while the remaining 128 belonged to Romans, Etruscans, Phœnicians, and other nations of antiquity, Professor Mantegazza reaches conclusions which go to confirm a remark made by Mr. Darwin in "The Descent of Man." "It appears," writes Darwin, "as if the posterior molar or wisdom teeth were tending to become rudimentary in the more civilized races of man." Professor Mantegazza finds that the wisdom-teeth are more frequently absent in the superior than in the inferior types, the exact proportion being 42·42 per cent, in skulls of the higher races against 19·86 in the lower. But atrophy of the third molar tooth occurs less frequently in the higher than in the lower races, viz., in 10·90 per cent, of the former, and in 20·58 per cent, of the latter. In the lower races the abnormal cases are practically equal to the normal, while in the higher they are much more numerous, the proportion being 62·91 per cent, to 37·09 per cent. Mantegazza is inclined to suppose that at a period more or less remote the third molar will disappear from the human jaw.

A New Plant.—A botanical discovery of considerable interest is announced in a letter, written by Dr. Beccari, from Sumatra. It is a gigantic aroid, which can only be compared with the Godwinia discovered by Seewann in Nicaragua. Dr. Beccari is as yet unable to determine the genus, but he believes it to be a Conophallus. The tuber of one plant was 1·40 metre in circumference, and two men were hardly able to carry it. From the tuber, as in the genus Amorphophallus, only one leaf is produced, which in form and segmentation does not differ much from that genus. But the dimensions are very different indeed. The stalk at the base in one instance was 90 centimetres in girth, was slightly less at the apex, and reached the height of 3·5 metres; its surface was smooth, of a green color, with numerous small, white dots. The three branches into which it was divided at the top were each as large as a man's thigh, and were divided several times, forming altogether a frond not less than 3·1 metres long. The whole leaf covered an area of 15 metres circumference. The spadix of a plant found in fruit had the stalk-dimensions just given; the fruit-bearing portion was cylindrical, 75 centimetres in girth, 50 centimetres long, and was densely covered with olive-shaped fruit 35 to 40 millimetres long, and 35 millimetres in diameter, of a bright-red color, each containing two seeds.

Advantages of Oral Teaching.—It would not be easy to compress within equal space a greater amount of practical common sense than we find in a recent communication entitled "Our Schools," printed in "The Examiner." "I believe," writes the author, "that one of the great stumbling-blocks to boys is want of oral teaching, in a popular style, particularly among little boys. It is a notorious fact that the grown-up world generally learns geography and history by means of newspapers and reading accounts of current events with the aid of the maps which are published from time to time for the purpose. and, if boys were taught in the same popular manner at the commencement of their education, it would do lasting good. We must all remember the dreary toil of mastering geography by learning a quantity of details out of a book about the number of inhabitants, names of rivers, the trade, the religion, and manners and customs of any country, without any means of impressing facts on the mind, while history becomes a positive treadmill when left to a boy's private reading. When the Prince of Wales went to India, if any one with an attractive manner of talking had taken a series of cartoons simply showing the rivers, the principal cities and mountain ranges, and some of the pictures published in the illustrated papers, he could, by arousing deep interest, have made the way easy for acquiring a fuller, more complete knowledge. The same mode of teaching would apply to the late European wars, the Indian famine, or any other great national event or calamity. We do this kind of thing in business matters every day of our lives in committees, on trials, and in all important transactions. It should be the same with boys; they should be interested in their subject before being set to master its drier details, which would, by this very introduction, lose much of their dryness."

Retentive Memories.—A number of instances of great retentiveness and accuracy of memory are recorded by a writer in "Chambers's Journal." Among the names mentioned is that of Dr. Robert Chambers, whose power of memory was very extraordinary. For example, on a certain occasion he was heard to say, "This day forty-seven years ago, at twenty minutes past two o'clock, I was passing" such a number of such a street, and met such and such a one. The author finds in Sir Walter Scott and in Charles Dickens a like accuracy of memory, and to this attributes no small share of their success as story-writers. Then a case is cited from one of Dr. Carpenter's writings of a clergyman who, on visiting Pevensey Castle, felt convinced he must have seen it before, and that when he did there were donkeys under the gateway, and some people on top of it. On inquiry he ascertained that he had been there with a picnic party, who made the excursion on donkeys, when he was only about eighteen months old. Sometimes the whole history of a lifetime will be flashed before the mind as in an instantaneous picture. That this occurs sometimes when death, or peril of death, is imminent, is quite certain. It may be that this occurs very frequently before actual death; but this we cannot know, as all the instances of which we have accounts are those in which a man has described his sensations after having been saved from dying—especially from drowning. "When all hope of being saved is gone," says the author, "and the very struggle with the water is now made without conscious effort, it would seem that, without being prompted by the will, the memory suddenly grasps at once the deeds of the life that now appears about to close, and at the same time—and this is the most singular fact of the phenomenon—recognizes the usual rectitude or wrong of each act [?]. There is," he continues, "a case of this kind recorded of an English naval officer, who thus remembered the events of his life at the moment when he was struggling hopelessly in the wake of the ship from which he had fallen; and he confessed that he had been especially struck by the sudden coming into his thoughts of a schoolboy lie that he had long forgotten."

Economic Statistics of the World.—A general review of the economic statistics of the world in 1877 is published by Professor Neumann Spallart, of Vienna; from it we take the following statements:

Railways.—In the last three decades the network of European railways has risen from 9,000 kilometres (5,580 miles) in 1847 to 154,200 kilometres[1] (95,604 miles) in 1877. Of these 154,200 kilometres 27,500 are in Great Britain and Ireland; 24,800 in Austro-Hungary; 23,400 in France; 18,000 in Russia; 30,000 in Germany. The remainder is distributed among the smaller states. According to these figures Europe has 150 kilometres of railway for each thousand square kilometres and 4·8 kilometres per 10,000 inhabitants. These ratios are exceeded in Belgium, Great Britain and Ireland, Switzerland, the Netherlands, etc.

America.—In 1830 the United States had 42 kilometres of railway; now they have 128,000 kilometres (79,360 miles), or 133 kilometres for every 1,000 square kilometres of surface, and 28 kilometres per 10,000 inhabitants. In the remainder of this continent there are 17,000 kilometres of railway, of which Canada has 7,000.

In India and Ceylon there are 11,000 kilometres, or 46 kilometres per 1,000 square kilometres of area and 12 kilometre per 10,000 inhabitants. In Africa there are 2,800 kilometres, whereof 1,800 belong to Egypt. Australia and New Zealand possess 4,000 kilometres of railway.

On all these railways are employed 62,000 locomotive-engines, 112,000 passenger carriages, and 1,500,000 freight-cars; they annually carry 1,150,000,000 passengers, and 16,000,000,000 quarters of freight.

Marine.—The merchant marine of Europe embraces in all 7,400 ocean steamships with a tonnage of 3,000,000 tons, of which totals the United Kingdom contributes 5,200 steamships and over 2,000,000,000 tons of freight.

Telegraphs.—At the beginning of 1877 Europe had 351,000 kilometres of telegraph lines, whereof 65,000 belonged to Russia, 54,000 to France, 48,000 to Germany, 40,000 to the United Kingdom. America had then 183,000 kilometres. The dispatches sent over European lines numbered 82,000,000 in 1876; those sent over American lines amounted to 23,000,000. Asia and Australia have each 38,000 to 39,000 kilometres, transmitting 2,500,000 dispatches. In Africa there are only 15,000 kilometres, almost exclusively in Egypt, Algiers, and Tunis, and the number of dispatches sent is 1,200,000. There are 560 submarine cables, representing a total length of 65,000 nautical miles.

Postal Service.—The postal service now extends to the uttermost bounds of civilization, embracing the whole globe, from Hammersfest to New Zealand.

In Europe over 3,000,000,000 letters and postal-cards are carried yearly. In this total the United Kingdom is represented by over 1,000,000,000; Germany by 700,000,000; France by 366,000,000; Austro-Hungary by 300,000,000; Italy by 120,000,000. This would give for England 33 letters per head of the population; for Switzerland, 24; Germany 15; France 10. Turkey figures for only 0·2 of a letter per capita. In America the number of letters and postal cards carried was 700,000,000; in Asia, 150,000,000; in Australia, 50,000,000; in Africa, 25,000,000.

Gas-Stoves and the Products of Combustion.—City people are wont to express their surprise at the stupidity of the countryman who extinguishes a gaslight by blowing it out, and then sleeps in the same room. Yet the same acute city people will set up a gas cooking-stove, and will never think of the necessity of carrying away the products of combustion. Plainly, in view of the prospective large employment of carburetted hydrogen gas as a domestic fuel, it behooves the sanitarian to emphasize the necessity of proper regard for sanitary requirements. The public will have to be instructed in the simplest elements of science, and drilled to heed the plainest teachings of every-day experience, or else the general introduction of gas as a fuel will at first occasion a fearful amount of mortality. The observations of the editor of the "Lancet," in a house in the "West End" of London—the fashionable quarter of that metropolis—might be repeated any day in the "best quarter" of our American cities. The editor of the "Lancet" visited the kitchen of the house in question, having been asked to give an opinion as to the wholesomeness or otherwise of the cooking arrangements. He found a gas hot-plate with five circles of burners, each circle having 12 or 15 jets, so that when the hot-plate was fully heated 60 or 80 jets were in active combustion. Each jet produced about two cubic feet of carbonic acid per hour, a total of 120 to 160 cubic feet, in addition to sulphurous acid. No chimney was provided for the escape of the gas, and the very intelligent inmates of the house could not understand why the cook looked so pale and ill; as for the cook herself, though she often felt "giddy and fit to fall upon the floor," she never suspected the gas-stove! Now, since each of the gas-jets had an effect equal to the respiration of one human being, it is evident that the population of that kitchen practically amounted at certain times to sixty or eighty persons; and the exhalations from this "black hole" had no way of escape except through the kitchen door and into the house. This instance of the stupidity of "intelligent" people is so typical that it deserves to become "classic."

Effects of a Diet of Shingle-Nails.—The cows of a large dairy-farm in Hungary having been all simultaneously seized with disease, the symptoms being high fever, difficult respiration, and inflation of the body, it was determined to slaughter two of them and to make an examination of the bodies. The organs of the chest appeared perfectly normal. On opening the stomach its contents were found partly fluid and partly of pappy consistence, and among this matter were discovered a number of shingle-nails of various lengths, some of them free, and others partially imbedded in the walls of the stomach. Renewed investigation cleared up the mystery as to how these nails got there. About a year before, a shed on the estate caught fire, and the shingles of the roof were torn off, nails and all, in the attempt to put out the flames. In the winter the damaged materials were burned in the farm-buildings as fire-wood, the ashes subsequently strewed upon a clover-field, and the nails contained in the latter unfortunately were raked up with the hay crop obtained from it in the following summer. Every cow upon the farm had to be slaughtered, and in every case nails were found in the second stomach.

The Electric Light as a Source of Nitric Acid.—It is known that, when combustion takes place at high temperatures, small quantities of the nitrogen and oxygen of atmospheric air combine, forming several oxides of nitrogen, many of which are strong, corrosive acids. This is the case when electric sparks are passed through air, also during combustion in air of hydrogen. It therefore appears probable that, as the temperature of the electric arc is undoubtedly very high, nitric acid, or some other oxide of nitrogen, might be produced by the electric light. This subject has been investigated experimentally by Mr. T. Wills, with results strongly confirmatory of this theoretical inference. The first experiment was rather surprising. A glass cylinder placed over an electric lamp (Foucault's regulator) for two minutes, and afterward examined, was seen to contain a perceptible amount of red fumes, due to peroxide of nitrogen (N2O4). The air surrounding the lamp was next drawn through a solution of potash, and the amount of nitric acid estimated; this gave ten to twelve grains of nitric acid produced per hour (it may eventually prove to be more, the difficulty being to collect the whole of it). The next step in the research will be to examine the various forms of electric light, with a view to determine the amount of nitric acid produced by each.

In an Ants' Nest.—The columns of the Popular Miscellany from month to month give evidence of the interest with which naturalists study the ways of ants. Indeed, the life-history of that interesting insect seems to be full of surprises for the persevering observer. Here is an account of a nest of Formica nigra, in which a number of Termites were kept as slaves. While entomologizing in Portugal in 1877, in the neighborhood of Cintra, Mr. Henry O. Forbes found a nest of F. nigra under a stone. On turning the stone over, he observed great consternation in the community, evidently caused by the fear lest a colony of Termes lucifugus, which the Formicas had enslaved, should escape. The Nigras instantly began seizing the Termites, driving them underground by the nearest orifices, in the mean time wrenching and pulling off their wings. In the nest there was also a large number of Termite larvæ, and the great object of the Nigras seemed to be to get these underground as speedily as possible. The ants fell on them with fierce impetuosity, seizing them anyhow and anywhere, dragging them against the most strenuous opposition into the nearest apertures of the underground home. Very often this opposition resulted in a long and savage fight, in which the larvæ were badly wounded, being deprived sometimes of their antennæ, sometimes of half their jaws, and not seldom killed outright. Occasionally, however, the larvæ were victorious, beating off the Formicas. The observer saw at the end of a long fight one larva drawn by its antennæ, while it strenuously held on to a small ball of earth which had proved a vain anchorage for its feet, for larva and clod together were dragged for a long distance through the grass. At last it seized one stalk so firmly that its enemy could not drag it farther; whereupon, after reconnoitering the ground for a little distance, the latter disappeared, but shortly returned with a companion, by whose aid the larva was detached. This done, the helper went his way, while the abductor proceeded with his captive till lost to view.

Pearls and their Origin.—People are still to be found who believe in the myth which ascribes to pearls a sort of animal nature—being born of other pearls, feeding like other animals, and growing larger by the conversion of food into their own substance. A glass tube purporting to contain some of these growing pearls and certain "grains of rice," on which they fed, was lately sent from Australia to Mr. Frank Buckland, who in turn placed it in the hands of a competent conchologist, Mr. Hugh Owen, for examination. Mr. Owen, honestly desirous of dissipating the crass ignorance which alone makes belief in such absurdities possible, takes the trouble to state briefly, in "Land and Water," the natural history of pearls, in substance as follows: Pearls are concretions found either attached to the interior of certain bivalve shells, or enveloped in the folds of the mantle of the animal that inhabits the shell; the latter are most valued. All pearls are formed of the same substance as that lining the inner surfaces of the shells in which they are formed. The peculiar luster is caused by alternate layers of thin membrane and carbonate of lime, and depends on very minute undulations of the layers. The most valuable pearls are found in the soft portions of the mollusca, and are believed to be originally a grain of sand, or some other irritating substance, which the animal covers with a nacreous deposit. That this is the correct theory is seen on cutting or slitting pearls, when each one is found to have a foreign body as a nucleus. Such being the natural history of pearls, the story of "young pearls feeding on rice" should not be heard outside of the nursery. It may be added that the "rice-grains" in the collection presented to Mr. Buckland are identified by Mr. Owen as marine shells of the genus Cypræa, the end or apex of each being carefully filed or ground off to represent the effect of having been fed on by the pearls.

Survival of Serious Brain Injury in a Pigeon.—A remarkable case of recovery of all the faculties in a pigeon from which four fifths of the upper portion of the cerebrum had been removed, is recorded by Dr. J. H. McQuillen, in the "Proceedings" of the Academy of Natural Sciences of Philadelphia. The author, who is Professor of Physiology in the Philadelphia Dental College, on February 4th of last year, exposed the cerebrum of a pigeon, and cut out four fifths of the upper portion in slices: this he did in illustrating to his class the fact that the sensorium thus exposed could be cut pinched, or burned, without any sign of pain on the part of the animal. The usual phenomena followed, viz., profound stupor, the bird standing motionless on the table, with eyes closed, head sunk between the shoulders, and feathers ruffled. At the close of the demonstration, this pigeon was given to Professor Emily White, M. D., of the Women's Medical College, with the request that an effort should be made to keep the bird alive, and ascertain whether the mutilated organ would regain its functions. In March a note was received from Professor White, in which she stated that the pigeon had apparently recovered all its faculties. "He is," it was added, "perhaps less excitable than normal, and seems perfectly tame, but bright." Dr. McQuillen at once sent for the bird, and observed with surprise the complete recovery of the voluntary movements of walking and flying, the power of feeding itself and drinking as usual, and the general manifestations of intelligence. The bird continued in full possession of its faculties for six months, and then was put to death and an examination made. On removing the scalp a fibrous structure, analogous to pericranium, was found, occupying the place from which the bone had been removed in making the vivisection. Cutting this away, a small amount of fluid escaped, and the cranial cavity thus exposed was found occupied by a white substance resembling the cerebral structure that had been removed six months before. Placing a section of the upper portion of this, which had been stained with hematoxyline, under the microscope, a number of bipolar cells characteristic of the gray structure were observed.

Pigments of the Hair.—By treating with dilute sulphuric acid different kinds of human hair, Mr. H. C. Sorby obtains three distinct pigments, a red, a yellow, and a black. The red pigment is probably convertible by oxidation into the yellow. Very red hair is characterized by the presence of the red constituent unmodified by any other coloring substance; golden hair has less of the red and more of the yellow pigment; in sandy-brown hair the black and red constituents are associated with a large proportion of the yellow; in dark-brown hair the black pigment is present in larger quantity, while in black hair this dark substance predominates over the rest. Singularly enough, Mr. Sorby found in the hair of a negro about the same proportion of the red pigment as in the very red hair of a European. If in this case the development of the black pigment had been checked by any cause, he would have presented the curious spectacle of a red-headed negro.

Wallace's Theory of Zoölogical Derivation.—To illustrate Wallace's theory of the derivation of all animals from the north, a writer in "Nature" designed a map of the world on a polar projection, the northern hemisphere being projected somewhat beyond the southern tropic. This map clearly shows how the land-surface of the globe is built around the pole, and exhibits the extremities of America, Africa, and Australia, extending into the great ocean. If, now, the subdivisional regions (zoölogically) of each of these three great projections, and of the whole, be marked in colors, a succession of zoölogical strata (so to speak) appears. By carrying an ideal section from the supposed center of creation in the north through either of these three great extremities, and thence to the nearer and afterward the more remote of their dependencies, we pass in each case through zoölogical strata of different types, until we arrive at those where no land mammals are to be found at all. And this succession in space, as evidenced by geography, corresponds in a rough way with the succession in time as revealed by geology: 1. As we recede in distance, we meet with increased dissimilarity. 2. This dissimilarity partakes of a recession in type. 3. Some of these geographical districts seem to have their counterparts in geological periods. The Ethiopian region, as Wallace has shown, presents us with the exiled Miocene fauna of Europe. Eocene forms may be seen in its dependency of Madagascar. Highly isolated Australia, with its marsupials, etc., appears as if it were still in the secondary age. Oceanic islands, such as New Zealand, give no land mammals at all. In others, the reptiles "possess the land."

Antiquity of the Practice of Inoculation.—Inoculation as a means of mitigating the severity of smallpox was practiced in Eastern countries ages before its introduction into the West by Lady Mary Wortley Montagu. The Chinese appear to have practiced it as early as the sixth century. Smallpox is by the Chinese called "heaven's flowers," and their term for inoculation is "cultivating heaven's flowers." Their mode of procedure is to pulverize the scabs taken from a smallpox patient, and to blow the powder thus obtained up the nostril of the child. The powder is injected into the left nostril in the case of a boy, and into the right in the case of a girl. It is impossible to tell whether the disease induced will be severe or not. In some years there are few if any deaths, at other times the mortality is much the same as that from smallpox. A lucky day is carefully chosen for the operation, and at a time when the child is in good health. No particular rules are observed in selecting the matter, except that it is always taken from a mild case of the disease. Gradually, however, vaccination is coming into use in China. The suspicion with which vaccination was formerly regarded by the people as a subtle device of the foreigners to destroy the inhabitants of the Central Flowery Kingdom is dying out, and Dr. Osgood, of Foochow, who has every opportunity of knowing, says that "vaccination is gaining ground every year, and is destined in time to drive out inoculation." But the process of substitution must necessarily be very slow in so strictly conservative a country as the Chinese Empire.

  1. One kilometre is about 58of a mile.