# Popular Science Monthly/Volume 20/January 1882/Popular Miscellany

POPULAR MISCELLANY.

Finding the Center of Population.—The computation of the center of population of a country, as explained by Mr. F. D. Y. Carpenter, who has performed the work for the United States, for the census of 1880, is not a simple or an easy process. As defined in the "Statistical Atlas" of 1874, this center is the point at which equilibrium would be reached were the country taken as a plane surface, itself without weight, but capable of sustaining weight, and loaded with its inhabitants, each individual being assumed to be of the same gravity as every other, and consequently to exert pressure on the pivotal point directly proportioned to his distance therefrom. In other words, it is the center of gravity of the population of the country. It may be illustrated otherwise, by saying that it is the point at which, if all the population should assemble, the aggregate distance traveled by all those coming from any two opposite points of the compass would be respectively equal. It is found approximately by assuming a point as nearly as possible to the true position of the center, and then finding its north, south, east, and west moments of population; that is, the four aggregate products formed by multiplying the local populations by the distances of their centers north and south of the assumed parallel, and east and west of the assumed meridian. The sums of the north and south moments, and those of the east and west moments should be severally equal to each other. The differences which will appear between the several sums in the trial-work, divided by the total population of the country, will give the measures of correction to be applied to the assumed point, in order to deduce the true center from it. In the case of a population so extensively and diversely scattered as that of the United States, there is room for any amount of refinement in the details of the calculation. The larger cities arc treated as special centers. Leaving them out, the population of the country is grouped by square degrees—that is, by the spaces, included between two consecutive degrees of latitude and of longitude, the centers of which, except where there are reasons for exception, are taken as the local centers of population. By this process, the center of population of the United States for 1880 is placed in latitude 39° 4' 8" and longitude 84° 39' 40", or at a point in Kenton County, Kentucky, one mile south of the Ohio River, and eight miles west by south from the heart of the city of Cincinnati. This location is, after all, only approximate, and extreme accuracy is hardly attainable under ordinary modes of calculation. In fixing it, the surface of the country has been assumed to be plane, whereas it is spherical or spheroidal, and a parallel of latitude has been made one of the axes, whereas the arc of a great circle should have been taken. Then there are differences in the kind of map-makers' projections that are used, all distorting the spheroidal surface in attempting to represent it as a plane, but some giving worse distortions than others. Mr. Carpenter believes that if it were practicable to make an absolutely correct calculation, the actual center would be found about thirty miles to the north and a trifle to the east of the present estimated location, or in Butler County, Ohio. The center is thrown so near the northern boundary, by the fact that our country in general shape is the segment of a zone; and the case is supposable, if the segment were extended far enough in longitude, in which the center of population would be situated entirely outside of the country.

Movements of Plants.—Mr. Thomas Meehan, of Philadelphia, has recently noticed some apparent irregularities in the motility of various plants which have not been adequately accounted for. The expansion and closing of the petals of Draba verna, which take place in connection with the diurnal erection and drooping of the pedicle, appear to require a clear light; yet while at one time the expansion seemed to be prevented by a cloudiness that hardly dimmed the Bun's rays, it was at another time not at all interfered with during a densely cloudy, warm, and moist day that followed a thundershower. The earliest flowers of Lamium amplexicaule are the largest ones in the Isle of Wight; here the case is reversed: the flowers never expand; and plants alongside of each other under the same conditions and external influences vary a week in the time of their flowering. The drooping branches of the Kilmarnock willow have grown from the upward branching Salix caprea without any known external influence to determine a different direction of growth, and they bear erect catkins, while erect branches bear pendulous ones. Such facts should teach us that external causes have but little influence with motility, and that in many cases a combination of circumstances controls the influences attributed to one. The facts will vary with various observations—those of one observer seeming rather to conflict with than to confirm another—and it is too soon to form any conclusion as to the motive cause.

Inscriptions of the Mound-Builders.—Major William S. Beebe, of Brooklyn, gave an interesting account, at the recent meeting of the American Association, of his efforts to decipher the inscriptions that have been found in the mounds at Davenport, Iowa, and Piqua, Ohio. Two pieces of slate were found in a mound at Davenport, one of which was inscribed on one side, the other on both. The stone inscribed on but one side bore on its surface a series of concentric circles, between the outer two of which were twelve equidistant signs, presumably the zodiacal signs. About two years after these slates were found, two terra-cotta tablets were dug up at Piqua, Ohio, bearing series similar to each other of characters, "evidently letters," ranged in horizontal lines, on four of which the letters were in each case six in number. In the fifth and remaining instance there were five lines, but this arrangement was at some distance in the longitudinal direction of the tablet from the groups first mentioned, which were in both cases written in couples. Major Beebe claimed that these groups of six letters each, when separated into alternate threes and read right and left respectively, are the names of eight of the zodiacal signs on the Davenport slate—the other four signs, Capricorn, Aries, Cancer, and Libra, being represented by four initial letters on the back of one of the Piqua tablets. These letters represent the North, South, East, and West, respectively, and correspond to the "world-holders," as they were called, to which a particular importance was attached. The most significant detail of this identification is that the forms of the letters are almost precisely those that occur about the Mediterranean, whose phonetic values have been determined by Alois Hess in his work on the classification of old Spanish coins. Should this identification be correct, the point arises whether this alphabet originated in this country or in the old. Major Beebe claims to have traced each form of letter to aboriginal American picture-symbols, in which the same significance obtains in both European and American forms. Having fixed the significance of the letters, he has, he says, deciphered the inscription on the stone from Grave Creek, West Virginia, and that on the axe found at Pemberton, New Jersey.

Cremation in Italy.—As an evidence of the progress which cremation is making in Italy, the Journal of the Italian Hygienic Society states that one hundred and thirty-nine cremations have taken place in the crematories at Milan and Lodi, and that the number increases every month. Nine societies and nine committees for cremation exist in the kingdom, and new crematories are to be built at Rome, Varese, Leghorn, Pavia, Cremona, and Udine. Signor Loria, of Milan, has recently offered the municipality of the city twenty thousand francs for the establishment and maintenance of a laboratory for making autopsies of bodies destined to be incinerated when that is deemed expedient, or may be called for by the circumstances of the case. The French Government apparently does not favor the movement much. To a petition from the municipality of Paris, asking permission to incinerate bodies in certain cases, the Minister of the Interior replied that the law of the year XII, prescribing burial, would have first to be repealed, and the Government did not consider that the question had yet been enough studied by science or advanced in public opinion to justify the assumption of the responsibility of presenting it to the legislative bodies.

Sanitation of Cemeteries.—The Municipal Council of Paris in 1879 appointed a commission on the sanitation of cemeteries, with instructions to inquire especially whether that object could not be fully accomplished by the employment of chemical or physical agents combined with drainage; whether it could be assured for the future by the same means; and whether the disappearance of the organic parts of bodies could not be expedited by the addition, in the coffins or the soil, of chemical agents and other substances; and whether such additions were likely to do any harm. This committee, after a careful examination of the soil and air within the cemeteries and around them, has reported that, though accidents may have occurred from the escape of gases in close tombs and churches where bodies have been buried, they are not to be feared in the open air; that deleterious gases produced by the decomposition of corpses buried at the depth of a metre and a half (five feet) do not reach the surface; that nearly the entire organic constituents of dead bodies are consumed in the course of five years, and that consequently a tolerably permeable soil is not likely to be saturated; that this consumption may be accelerated by drainage; and that there is no danger to wells if they are at a reasonable distance away. These conclusions agree fully with those expressed by M Robinet in his article "Are Cemeteries Unhealthy? "[1] They may possibly be modified in consequence of the researches that have brought the cadaveric alkaloids, the ptomaines, to light, and of M. Pasteur's discoveries concerning the preservation of carbuncular germs in the soil.

Rodents, Fossil and Living.—M. E. L. Trouessart, in attempting to explain the geographical distribution of living and fossil rodents from the point of view of the doctrine of evolution, divides the living rodents into four principal groups, or tribes: the cosmopolitan rats and their allies, which appear to find everywhere and under all circumstances conditions favorable to their existence and multiplication; the sciuromorphs (squirrels and marmots) and the lagomorphs (hares), almost exclusively of the northern hemisphere; and the hystricomorphs (porcupines, Guinea-pigs, and capybaras), which are now confined to the southern hemisphere. The study of the fossil rodents shows that these four types were neither as narrowly confined to particular regions nor, except the hares, as clearly defined and separated from each other as now. The types of the southern hemisphere were represented during the Miocene epoch in the north of both continents, and appear to have been driven south by glacial cold. The existing types of rodents first appear in the Eocene epoch, and by the side of them mammals with similar dentition, of which the chiromys of Madagascar may be regarded as the last survivor. Some of the mammals of the secondary epoch present the characteristic incisors of the rodents, with molars indicating a carnivorous or at least a more omnivorous nature than that of. the great majority of the modern rodents. Similar incisors are found in a number of insectivorous animals, as, for example, among the shrew-mice and several types of ungulates. We are thus led to conclude that this type of the rodents played at the beginning of the Tertiary period an important part in the history of a number of orders which have now become more specialized.

Whales and their Habits.—A correspondent of "Land and Water," who accompanied the Dundee whaling fleet to Davis Strait and Lancaster Sound last summer, mentions the change that has taken place in the geographical distribution of the Arctic whale. A century or two ago this animal was found everywhere north of the sixtieth degree of latitude, and extended many degrees farther south on the east coast of America. It abounded on the northern shores of Europe and the coasts of Iceland and Greenland, frequenting the islands of Jan Meyen and Spitzbergen in incredible numbers. Now it has deserted Spitzbergen and the north of Europe, it is becoming rare on the coasts of Greenland, and seems to be retiring farther into the unpenetrated recesses of the Polar Sea. Whalemen are not agreed as to whether the-animals are actually diminishing in numbers. Some believe that they are still as numerous as they were at the beginning of the century; others predict that the time of their total extinction is approaching. They are still sometimes seen in enormous numbers. Whales exceeding forty-seven and forty-eight feet in length are caught every year. Captain Deuchars, of the Dundee fleet, two years ago took a whale sixty-five feet long, the "bone" of which measured twelve feet ten inches, and which gave twenty-four tons of pure oil. The largest whale ever caught in Davis Strait, in 1849, had a "bone" fourteen feet long, and yielded twenty-seven tons of oil. The destruction of "suckers," or baby whales, which is considerable, may have something to do with the present decadence of the fishery. Whalemen think that no animal should be killed whose "bone" is not more than six feet long. Whales may live to a very great, but no one knows to how great, an age. Although dead ones are often found floating on the water, none are ever discovered that have died from natural causes. Whales are monogamous, and are much attached to their consorts. The correspondent who furnishes these facts tells of an animal which came back every day for a fortnight through great peril from the fleet to the place where its mate had been taken, regularly going over the course followed by her in her flight, looking for her. The animals sleep on the surface of the water, enjoy fine weather and sunshine, and are often seen at play on bright days. When they are together in large numbers, the water becomes covered with an oily exudation from their bodies, which has a sickly smell, and attracts flocks of "molly" petrels. They can live only on the most minute marine animals, for, though a whale's mouth "would hold a whale-boat, with all its crew, its gullet would be choked by a herring. When feeding, it swims through the water with its mouth wide open, a constant stream passing in at the front, through the upright whalebone plates at the sides, and out again at the back. The small animals which form its food are entangled in the long hairs which fringe the internal edges of the plates, and from time to time, as they become collected in sufficient numbers, the whale closes its mouth, raises its tongue, and swallows the mass." Its favorite food is a black pteropodous mollusk, resembling a humble-bee, and, after this, jellyfish, of which it takes millions to make a meal. Fortunately for the whale, these creatures go closely massed together in shoals many square miles in extent. After man, the whale's worst enemy is the grampus, which attacks it savagely, and is very destructive to the species. Its protection from both enemies is the ice; and it is, consequently, now found almost exclusively in the neighborhood of ice.

Typography and Eyesight.—Dr. Javal considers the subject of typography in relation to the hygiene of the eyes in the "Revue Scientifique." His conclusions differ materially only in a few points from those which Professor Herman Cohn has published. He believes it important to make the several letters, particularly those which are allied in form, as distinct as possible, and therefore favors those fashions in the cutting of the types which tend to accentuate the distinctions. The superior importance of the upper part of the letters, which is generally recognized, is enforced by the fact that in the case of the irregularities in the lines occasioned by the "long letters," eighty-five instances occur in which the long strokes rise above the line to fifteen in which they fall below it. Of the groups of letters resembling each other the members of the one composed of a, c, e, o, and s, are most likely to be confounded with each other, and more clear distinctions in the formation of their upper curves are eminently desirable. The strokes of which the letters are composed should not be made so thick as to blur the figure of the whole letter, which is the feature the practiced reader regards; and only young readers require a particularly heavy stroke. The thin lines that cut off the strokes at either end are not without importance; and Dr. Javal prefers the English method of drawing them so as to leave a curve between the stroke and the line, to the French method of leaving a sharp angle. These lines may be used with good effect, with slight variations in their position to assist in marking distinctions between letters which are otherwise somewhat alike. Dr. Javal regards the width of the letters as of more importance than their height, and the spacing between them as of more moment than the separation of the lines by leads; he does not consider leaded matter as really more legible than "solid"; and he ascribes a superior legibility in English books to the predominance of short words, giving more horizontal spacing. He would prefer a large type "solid" to a finer type leaded, although he admits that a "solid" page has a blackish, heavy, and somewhat disagreeable aspect. If attention is paid to his views regarding the breadth of the letters and the inter-literal spacing, he believes that the height, in the case of ordinary reading matter, may be considerably reduced without marring the legibility. Different considerations must prevail in regard to schoolbooks, in which the typography must vary according to the age of the pupil, within limits which can be determined only by experience.

Accommodative Cultivation of Infections Organisms.—Dr. A. Wernich has considered, in "Kosmos," the extent to which the molds, the microbic parasites of the body, and the germs of infection, are able to adapt themselves to new conditions of existence, assume new forms, and produce different effects. When microbes are observed in great numbers, as they may be sometimes in the tissues and secretions even of healthy persons, much more of sickly ones, the temptation is very strong to associate them with the production of disease, and is apt to mislead. Naegele has expressed himself in favor of the doctrine of transformation, and says that the same fungoid, transferred successively from one medium to another, may produce, in milk, lactic acid; in meat, putrefaction; in wine, gum; in the ground, nothing; in the human body, disease; and that it may, in each place, gradually adapt itself to the new conditions, and even, in the course of successive transformations, acquire new facilities for adaptation. If four vessels, carefully cleansed, are tilled with different fluids—such as carbolic acid, urine, Cohn's mineral plant-food, and Pasteur's fluid—all clear of bacteria, and a drop of the same putrefactive mixture is added to each of them, they will, in the course of forty-eight hours, show very different degrees of disturbance, according to their adaptation to promote the growth of the infective organisms. If the organisms themselves are examined, they will be found, although all originating from the same source, to be only similar, not identical. Even Pasteur, who stoutly advocates the specificity of the ferments, has been obliged to admit a few exceptions to his theory. Dr. Wernich had already called attention to observations by himself and others which tended to show that fungoids, which seemed harmless growths on the more exposed tissues, might, if the capacity of the body for resistance should be depreciated, become aggressive, and develop dangerous disorders. Grawitz cultivated a mold that grows on sour solids, but does not flourish in the bodies of animals, through successive generations, till he adapted it to a higher temperature than its natural one, to pastes, sweetened and alkaline fluids, and to blood. A living animal inoculated with spores of the last variety died in a few hours in consequence of a general development of the fungoid vegetation, particularly in the kidneys and liver. Dr. Wernich believes that he has evidence that the strength of the infective qualities of these organisms may be greatly increased by an accommodative culture. Cultivation in substances unfavorable to their growth is, on the other hand, found to cause a depreciation of their inoculative efficacy. If we select the most favorable substance for the growth of a mold, and plant upon it the most vigorous stocks we can obtain, we will soon perceive unmistakable indications of an increase of vigor. The period required for the development of the germs is shortened, and the organisms give way to their successors of the next generation in continually diminishing periods. The infective force becomes so much greater that the slightest contact is sufficient to effect a transplantation to a new medium, and the greatest pains are necessary to prevent a transfer without apparent contact of spores of the same kind as those which, subjected to unfavorable conditions of culture, require painful attention to induce them to take root in any new soil. A similar development of activity and infective power may be observed in the case of epidemics. The germs of disease do not exhibit their full vitality at once, as do poisons when absorbed, but require a period of incubation and the favor of diminished power of resistance in the body before they can exhibit their full effect. The first cases are indefinite, and hardly recognizable in their real character, and affect only the weakly; as the epidemic acquires strength, its manifestations are mere determinate, and it affects all. The manner in which this growth of activity is produced may be illustrated by experiments that have been made in the inoculation of animals, in which an increase in infective power has been very distinctly perceived to accompany each successive transfer from one animal to another. Dr. Wernich suggests that there are some questions relating to the subject that need yet to be explained, and that it will not be safe to form definite conclusions upon it until after further investigation.

Explosive Force of Coal-Dust.—The Rev. H. C. Hovey has communicated to the "American Journal of Science" the results of the investigations of Mr. Gilpin, Inspector of Mines for Nova Scotia, into the part played by coal-dust in spreading and augmenting the explosions which took place in the Albion mine in November of last year. The mine was thoroughly ventilated, and was reported by the night-watchman, an hour before the explosions began, to be free from gas, except in small and harmless quantities. Yet the explosions, once begun, were continued at intervals till the mine was all aflame and had to be flooded. On examining the gallery shortly after the original explosion, dead bodies of men and horses were found six hundred yards from the shafts, and the wood-work was splintered, but nothing bore any marks of fire, "and the conclusion was plainly justifiable that the flame of the explosion had not extended thus far. The walls of the galleries had been swept clear of timber, and presented the appearance of having been brushed with a broom. Volumes of coal-dust had been driven along by the force of the blast, and lay in waves and drifts on the floor of the levels, into which the party sank to their knees. It was found that clouds of the finer particles had been carried to the shaft and beyond it into the main north level, where a secondary explosion had taken place. . . . Secondary explosions caused by extracted or generated gas are nearly always in the vicinity of the first one; but here is a case where the second was half a mile from the first, with an intervening space of at least a quarter of a mile known to have been free from flame and presumed to be free from gas, because men were in it with lamps which showed no indications of its presence." The conclusion is drawn that the fine dry particles were driven on by the force of the first explosion across the shaft, where the dampness preserved them, into the "lamp-cabin," where they were readily ignited by the lamp which was kept burning openly, and thus caused the second explosion; "and it is probable that the same agency was efficient in producing, or at least augmenting, the subsequent explosions that made it necessary to flood the whole mine." A competent explanation on chemical principles of the remarkable exhibition of force and heat accompanying dust-explosions is needed.

Significance of Ancient Masons' Marks.—Professor Franz Rziha, of Vienna, has published the results of investigations, to which he has devoted many years, into the origin and meaning of the masons' marks which arc frequent in the constructions of antiquity and the middle ages, and which he specifies as occurring in Grecian, Roman, and Syrian buildings, as well as in later ones. They have been regarded as mystic signs, arbitrary marks, private signs, or simply as letters. Professor Rziha believes that they had a far wider significance, and that they formed, before the now recognized laws of statics on which the building art rests were made known by Galileo, the means by which the master transmitted to his students the secrets of his art, and to his workmen the principles of his plan. Particular figures were employed as a kind of a graphic key to the conditions of a consistent structure. The circle, square, cross, and triangle furnished the four elements of graphic delineation; the compass, rule, and square were the three tools absolutely necessary to guide the work, and were indispensable in securing the proportions best adapted to give strength to all parts of the building. The geometrical properties and relations of the figures used thus served to indicate the proportions that were to be obtained. Professor Rziha maintains that the figures were never arbitrary, but that they were always derived from and conformable to common geometrical types. A comparison of more than five thousand masons' marks which he has made shows that, however independently individual signs may have been chosen, the combination of the lines is subject to a law in the shape of a geometrical pattern, of which the lines, whether straight or curved, must be a part. He has traced out some of these original designs, and has been able to adapt the lines of the marks to them without any artificial straining—in strong confirmation, he believes, of his theory. After reviewing the modifications which these marks underwent in time and in different countries, Professor Rziha shows how it is possible to ascertain from them the ages at which buildings were erected.

Physiological Immunities of the Jews.—The "Revue Scientifique" has drawn the conclusion, from a comparison of the vital statistics of different countries, that the Jews nearly everywhere enjoy certain physiological immunities which distinguish them from the other inhabitants, among which are the following: their general fecundity (proportion of births to the whole number) is less; while the relative fruitfulness of their marriages to those of other races varies in different places; a greater proportion of their children survive everywhere; illegitimate births and still-born children are more rare among them; the proportion of males to females among the births is greater; their mortality is lighter, the mean duration of life is greater; they increase more rapidly by the excess of births over deaths; while they do not escape them entirely, they are less generally and less severely afflicted by contagious diseases; they are comparatively exempt from such diseases as consumption and scrofula; and they have the faculty of becoming acclimated and multiplying in all latitudes. These immunities are observed, notwithstanding the apparent condition of the Jews who enjoy them may be most miserable, notwithstanding the frequency of marriages of relatives among them, and notwithstanding the unwholesome conditions of the city life to which they mostly confine themselves. They may be explained as the consequence of the operation of a variety of causes, among which are suggested an inherent superior vitality in the race; the continued preservation of its purity from admixture with foreign blood; the faithful observance of the rules of hygiene laid down in Deuteronomy, which are particularly adapted to hot climates and hot seasons; the salutary influence of early marriages, of the spirit of order and economy, of moderation in tastes, of a comparative severity of manners, and of the domesticity of Jewish family life. It may be, too, that the misery in the Jewish quarters of European cities is more apparent than real, and that their inhabitants are really better off than the people around them. The facts are brought out in the statistics from which these conclusions are drawn, that Jews are quite liable to cerebral affections, and also to diseases that afflict mature and aged persons. The latter fact is explained by the existence of a greater proportion of mature and aged persons among them.

Constitution of Comet b, 1881.—The spectral phenomena and constitution of the cornet were the subjects of several papers at the sessions of the French Academy of Sciences of June 27th and July 11th. Mr. Hugging stated that the lines as shown in his photographs indicated the presence of nitrogen with carbon and hydrogen, probably as cyanogen. M. Berthelot remarked that the exhibition of the lines of hydrocyanic acid would furnish an argument for the hypothesis of the electric origin of the light, as the spectra of acetylene and hydrocyanic acid are characteristic of the electrical illumination of a gas containing carbon, hydrogen, and nitrogen, whether free or in combination. M. Thollon described the nucleus as giving a brilliant continuous spectrum, and the nebulosity around the nucleus as showing three bands, one quite distinct, the others dim, separated upon a ground forming a continuous spectrum. The spectrum of the bands resembled that given by the blue flame of alcohol, and therefore indicated the presence of carbon or some of its compounds. M. Wolff recognized—1. A wide continuous spectrum, pale, but visible in all the regions of the comet; 2. A continuous spectrum, almost linear, lively bright, given by the nucleus; 3. The spectrum of the three bands—yellow, green, and blue—characteristic of the light of all the comets hitherto examined. The existence of a solid or liquid matter, luminous either by itself or by reflection, was indicated in the nucleus, and that of an incandescent gas, probably acetylene, in the surrounding nebulosity, while the light of the tail appears to come from a luminous or simply illuminated pulverulent matter. The polariscopic observations indicated the existence of reflected light, that is, of nongaseous matter endowed with the power of reflection. M. Thollon noticed the modifications that took place in the spectrum as the comet receded from the sun. The violet rays were soon extinguished, while the yellow and red rays continued of full brilliancy. The bands appeared nearer the nucleus every day till the first day of July, when they were seen on the nucleus itself. M. Thollon supposes that the mass of the comet is formed partly of an incandescent gas, characterized by the banded spectrum, and partly of an incandescent solid or liquid matter in a state of extreme division, emitting a proper white light, and also capable of reflecting a part of the light it receives from the sun.

A South African River-Antelope.—Major Serpa Pinto, the African traveler, found on the Cuchibi a new antelope, of curious and remarkable habits. It bears, he says, among the Bihenos the name of quichôbo and among the Ambuellas that of buzi. It is of the size, when full grown, of a one year-old steer, has dark-gray hair, extremely smooth, straight horns, about two feet long, and set at a slight angle to each other, "twisted around the axis without losing their rectilinear shape," and terminating in a broad spiral. The feet are furnished with long hoofs similar to those of the sheep, and are curved at their points; and this arrangement, together with the sedentary habits of the animal, renders this remarkable ruminant unfitted for running. "Its life is therefore, in a great measure, passed in the water, it never straying far from the river-banks, on to which it crawls for pasture, and then chiefly in the night-time. It sleeps and reposes in the water. Its diving powers are equal, if not superior, to those of the hippopotamus. During sleep it comes near to the surface of the water, so as to show half its horns above it. It is very timid by nature, and plunges to the bottom of the river at the slightest symptom of danger. It can easily be captured and killed, so that the natives hunt it successfully, turning to account its magnificent skin and feeding off its carcass, which is, however, but poor meat. Upon leaving the water for pasture, its little skill in running allows the natives to take it alive; and it is not dangerous even at bay, like most of the antelope tribe. The female, as well as the male, is furnished with horns. There are many points of contrast between the life of this strange ruminant and that of the hippopotamus, its near neighbor. The rivers Cubangui, Cuchibi, and the upper Cuando offer a refuge to thousands of quichobos, while they do not appear either in the lower Cuando or the Zambesi. I explain this fact by the greater ferocity of the crocodiles in the Zambesi and lower Cuando. which would make short work of so defenseless an animal if it ventured to show itself in their waters."

Does Sea-Water contain Free Carbonic Acid Gas?—M. P. Martin Duncan maintains that carbonic-acid gas is not present in seawater in a free state, and cites in support of his view Tornö, of the Norwegian Deep-Sea Expedition, who has been quoted, erroneously it seems, on the opposite side. It appears from a careful examination of Tornö's essay that that author, in the course of his experiments, found that sea-water had an alkaline reaction, and then began to believe that the carbonic-acid gas which had been taken from the water in other experiments had been produced by the decomposition of neutral carbonates during the boiling. He then proved by experiment that the saline mixture in sea-water, on the temperature being raised to the boiling-point, decomposed neutral carbonates, and that all previous experiments for measuring the carbonic-acid gas in sea-water had been faulty. Of ninety-seven milligrammes of gas per litre of water found in one specimen, he estimated that about fifty-three milligrammes entered into the formation of neutral carbonates, and that the remaining forty-four milligrammes, instead of occurring free as gas, united with the carbonates to form bicarbonates. In one passage of his essay he speaks of sea-water as "an alkaline fluid which does not contain the smallest trace of free carbonic acid."

Photometry.—M. J. Janssen attaches importance to the application of photography to photometric measurements. It not only permits the registration of all the visible rays, but also reaches the ultra-violet rays, and is competent to give valuable ideas relative to the temperature of bodies. While ordinary photometric comparisons between two sources of light are essentially fugitive, and require the simultaneous presence of both bodies, photography furnishes permanent terms of comparison which we may bring to bear whenever we will, and may even bequeath to the future. The relative photogenic intensities of two different sources may be easily ascertained by causing them to act in succession on two similar plates. Comparisons of the photographic power of the sun and a star may be made directly, but it is necessary to obtain an image of the star of perceptible dimensions; this may be done by putting the plate on which the image is to be received out of focus, so that the rays from the star, instead of falling upon a point, shall form a small circle of light.

Disinfection of Alcohol.—M. Naudlne recently described to the Chemical Society of Paris a method which he had discovered for relieving alcohol of the bad taste it often acquires from the substances from which it is distilled. This spirit, as prepared from various grains, fruits, beet-roots, etc., is produced in many qualities, each of which acquires some special and relatively disagreeable flavor from whatever article has been subjected to distillation; and the alcohols are therefore classified in the arts according to the sources from which they are derived, and subdivided into those of "good taste," "middling taste, and "bad taste." Other alcohols are found along with the vinous alcohol in fermentation, but, as a rule, they do not materially affect its taste. The case is different with the aldehydic or acetonic bodies that are produced, whose pronounced and disagreeable taste is obstinately persistent in rectification. The methods which have hitherto been employed to take away these tastes depend on oxidation; this acts, however, upon the alcohol itself, and generates odorous ethereal substances which only give another bad taste instead of the original one. No better results have been obtained with other substances that have been recommended, including potash, soda, oil, fat, soap, and sodium. M. Naudine has adopted a course which has been suggested by the fact that hydrogen, in a nascent state, converts the acetones into secondary alcohols. His method consists in the subjection of the alcohol to be purified to the action of the Gladstone and Triber reducing pile, or a similar battery, whereby hydrogen is developed and acts immediately upon the impurities of the spirit.

Speed of Explosives.—M. Berthelot has been investigating the speed with which explosive phenomena are propagated in gases. For this purpose, he filled with the explosive mixture of oxygen and hydrogen, carbonic oxide, and oxygen under atmospheric pressure, an iron tube about sixteen inches long and a third of an inch in bore, so arranged that the passage of an explosive could be accurately registered at a point close to where the spark was applied, at the middle, and at the farther end of the tube. The experiment showed the speed of propagation to be about twenty-five hundred metres (8,125 feet) a second. The results should not be regarded as furnishing the absolute value of the speed of the explosive force, for the quantities measured are too small for that; but they at least give an indication that the speed is much greater than had been supposed. Bunsen, for example, in 1867, had estimated it at thirty-four metres a second for detonating gas, and one metre for carbonic oxide mixed with oxygen. The rapid propagation of explosive phenomena appears to be due to the transmission of the successive shocks of the gaseous molecules, which have been brought into a vibratory condition more intense than the heat disengaged in their combination. The phenomena of explosion are, then, more complex than a simple movement of transmission, or even than the propagation of a sonorous wave.

Fossilized Standing Trees.—M. Fayol has observed fossilized trees standing perpendicular to the planes of stratification of the beds that contain them, in the coal measures of Commentry. In the bed of Boseaux the trunks are so numerous as to resemble a fossil forest. The standing trees are fragments of trunks, without branches or roots, and occur generally in the grits, occasionally in the conglomerates, rarely in the shales, but not in the coal-beds. Prostrate trees are numerous in the shales, less abundant in the grits, and rare in the conglomerates, while numerous traces of them may be distinguished in certain parts of the coal-beds. The prostrate trees are a hundred times more numerous than the standing ones, and are found almost everywhere in the beds. These facts may be explained as the results of a transporting movement. A recently pulled-up plant, when thrown in the water, stands vertically, then sinks to the bottom in the same position, and afterward falls prostrate, remaining in each position for some hours or even days. If the trees were carried by the current to a lake or estuary, they would, according to the condition they were in, either float around for a while or sink at once, and would become fossilized in the position they took.

Disinfecting Powers of Sulphurous Acid.—Dr. Victor Fatio, of Geneva, has made a series of interesting experiments on the disinfecting power of sulphurous acid, particularly with reference to the destruction of the phylloxera and its eggs. From them he has found that the application of the acid, in the proportion of fifty cubic centimetres of the liquid acid to one cubic metre of air, is sufficient to kill all the phylloxera and eggs in a closed box in two hours; that the same effects may be obtained immediately in the open air by sprinkling the box with fifty cubic centimetres of the acid to one square metre of surface; that confinement for a few minutes with the former proportion of acid is sufficient to kill the phylloxera and soft insects of an analogous nature and their eggs, and purely herbaceous plants, while dry seeds exposed to it retain their germinative powers; and that its application is equally efficacious against the parasites in museums, while it does not harm the specimens which they infest. Plants and insects of a moist texture are the more readily affected by the acid. A high temperature is favorable to the operation by promoting the diffusion of the acid gas; a moist atmosphere is against it, by its tendency to hold the gas in solution. The application of the anhydrous acid has advantages over that of burning sulphur in that it can be made where sulphur can not be burned, is safer, and more convenient.

1. Published in the "Popular Science Monthly" for September, 1881.