Popular Science Monthly/Volume 30/December 1886/Popular Miscellany

From Wikisource
Jump to: navigation, search
Popular Science Monthly Volume 30 December 1886  (1886) 
Popular Miscellany
 

POPULAR MISCELLANY.

The State and Public Health.—Professor Edward Orton, in an address before the Ohio State Medical Society, on "The Relation of the State to the Health of the People," asserts that "the manner in which we are doing much of our sanitary work is far below the best knowledge of our time, and is a serious reproach upon our civilization. We are expending enough, and more than enough, to give us ample protection from the diseases which threaten us, but our ill-devised plans and our worse-constructed work leave us still, to a large degree, within their power." There is much truth in this, and the reason for it is perhaps to be found in the fact that too much is done for the sake of doing, without taking sufficient pains to do intelligently. Professor Orton would remedy the evil by putting all local sanitary work under the control of municipal boards of health, "which should be measurably permanent bodies, and which should be intrusted with largo powers." The quality of permanence should be insisted upon, that the boards may profit by their mistakes, and learn as they go, and not, being renewed every little while, go on repeating the mistakes of their predecessors or blundering into new ones. Then Professor Orton would have the work of these local boards unified under a State Board—an important matter, in consideration of the extensive geographical fields that often come under common sanitary relations. Such general supervision is particularly called for in a State situated as Ohio is, which, through most of its area at least, must depend for the future, as it does in the present, upon its rivers and lakes for its water-supply; and the question of guarding these sources becomes one of the gravest importance, which a State Board or its equivalent only is competent to deal with.


Bacterial Products as Antidotes for Bacteria.—D. E. Salmon communicated to the American Association the results of experiments which he had made in neutralizing the pathic effects of bacteria by means of the chemical products of bacterial action. They had been made upon pigeons with the bacteria of the swine-plague virus and their products. Since the demonstration of the germ theory of disease, it has become evident that there are three possible explanations of the action of these products: 1. Something is deposited in the body during the attack of disease that is unfavorable to the specific germ. 2. Something is exhausted which is essential to the development of the germ. 3. The living tissues acquire such a tolerance for the germ, or for a poison which it produces, that they are no longer affected by it. If either the first or the third of these explanations is correct, it would appear possible that immunity might be gained by introducing into the tissues the liquids in which the specific germs have been cultivated, and from which they had been removed by filtration, or in which they have been killed by suitable methods. The speaker had long been convinced of the correctness of this supposition, but it was only recently that he had been able to make a satisfactory demonstration of the principle.


Visions of the Blind.—Mr. J. Jastrow had an interesting paper, at the American Association, on "The Dreams of the Blind." Vision in dreams is connected with a recollection of sight, and the fact of its manifestation would mean that in the dreamer's brain there is developed a sight-center, the spontaneous activity of which is the material substratum of his dreams. Brain-centers, we know from observation and experiments on animals, are of slow growth. By asking what is the latest age at which a child may become totally blind and still retain dream-vision, we will be asking how long a time is necessary for the sight-center to develop, and sufficiently to enable it to function without further retinal stimulation. "Two hundred blind persons (mostly young) in the institutions for the blind at Baltimore and Philadelphia, were questioned in detail in regard to their dreams, and from their answers I conclude that the critical age is between the fifth and the seventh year. Those losing their sight before this age have no more vision in their dreams than if they were blind from birth. Those who become blind during this period may or may not lose dream-vision; while those whose eyesight is destroyed after this period find themselves quite on a par with seeing persons in dream-life. Only cases of total blindness are employed as a basis for this conclusion. With regard to cases of partial blindness it is found that the same period divides those whose dream-vision is brighter and more vivid than the partial sight of waking life from those whose waking life furnishes, though filled with imperfect sensations of sight, the material for dream-images."


The Cause of the Charleston Earthquake.—The theories of the causes of earthquakes are almost as various as the phenomena themselves; and it is the general opinion of those who have most carefully studied the subject that no single cause is competent to account for all that occur. The most evident fact about the cause of the recent shocks by which Charleston has been afflicted is, that there is nothing volcanic about it. Otherwise, our geologists incline to the belief that they are the concomitant of a line of weakness extending near the Atlantic coast from about Troy, New York, by Baltimore, Washington, and Richmond, to the Carolinas, and that the phenomena were immediately the result of a renewed faulting or displacement in the latter region. Tidal action may have had something to do with it; and notice has been taken of the fact that at the time of the severe shock at Charleston, the moon had been new, at perigee only about sixty hours, or a fair time for the accumulation of the effect, previous to its occurrence. The fact particularly illustrates Perrey's theory of tides of the fluid interior of the earth. How little, however, is really known about the causes of this or of any other earthquake is somewhat amusingly illustrated by a remark of Professor Dawson's the day after he had delivered his address as President of the British Association, and after the news had reached him of the disaster in Charleston. "The phenomena of the present earthquake convulsions in America and elsewhere, but particularly in America," he said, "are extremely puzzling, and completely upset some of the conclusions set forth in the address I read last evening." The Geological Survey has sent out a circular asking from observers as definite statements as they can obtain respecting the details of the phenomena. The questions have reference to the perceptible occurrence of the shock; its exact hour, minute, and second in standard time; the duration of the shocks; the accompanying noise, if any; the number, etc., of the shocks; the measure of intensity—whether very light, light, moderate, strong, or severe; the possibility of the existence of any other cause for what happened than an earthquake; and whatever other particulars of interest may have been noticed or learned by hearsay.


Mr. Darwin on Geologic Time.—Mr. G. H. Darwin, President of the Geological Section of the British Association, made a survey of the theories of geological time, including those of Mr. Croll and Sir William Thomson, and concluded from them that something has been acquired to our edge, but that much more remains still to be determined. It seems as likely that in this problem geology and meteorology will pass the word of command to physics as the converse. At present our knowledge of a definite limit to geological time has so little precision that we should do wrong to reject summarily any theories which appear to demand longer periods of time than those which now seem allowable. In each branch of science hypothesis forms the nucleus for the aggregation of observation, and as long as facts arc assimilated and co-ordinated we ought to follow our theory. Thus, even if there be some inconsistencies with a neighboring science, we may be justified in still holding to a theory, in the hope that further knowledge may enable us to remove the difficulties. There is no criterion as to what degree of inconsistency should compel us to give up a theory, and it should be borne in mind that many views have been utterly condemned when later knowledge has only shown us that in them we were only seeing the truth from another side.


An Inventory of the Glacial Drift.—Vice-President Chamberlin, in his address before the American Association's section of Geology and Geography, presented "An Inventory of our Glacial Drift." Having described the boundaries of the drift as represented on a wall-map, the speaker remarked that a wealth of significance lay in the sinuosities, vertical undulations, and varying characters of the southern border. It undulates over the face of the land essentially much as an arbitrary line from New York Harbor to Puget Sound, and could be reduced to horizontality—as it must have been to have marked the margin of some ancient ice-bearing body of water—only by incredible warpings and dislocations. The border presents three notable phases: one part terminating in a thickened belt, a terminal moraine; another in a thin margin; and a third in an attenuated border of scattered pebbles. The morainic border prevails in the Atlantic region and on or near the limit as far west as Central Ohio. Throughout the rest of the stretch to the Rocky Mountains the attenuated edges prevail. Of unstratified bowldery clays or tills, there is the richest variety, ranging throug diverse combinations of material, texture, and aggregation. Of moraines, terminal, lateral, medial, and intermediate varieties are found. The great terminal moraines overshadow all others in interest and importance. Outside of the chief moraines are occasional belts of older drift aggregated in the similitude of peripheral moraines. Back from the two principal terminal moraines lie similar partially determined belts, usually of less prominence and continuity. Our most unique moraines are the interlobate, developed between the tongues into which the ice-sheet of the second epoch was divided at its margin, of which about a dozen, in half as many States, are recognized. Beautiful lateral moraines abound in the mountainous regions of the West, and some were developed by local glaciation supervening upon the ice retreat of the East. Our medial moraines are unimportant, and confined essentially to mountainous glaciation. Allied to the true moraines are special forms of aggregation of the sub-glacial débris. Two classes commonly embraced in the assorted drifts should be excluded from them: the "orange sands" of the Mississippi Valley, which do not appear to possess the distinctive characteristics of glacial gravels, but are residuary in aspect; and the secondary drifts, or those that have been reworked by wholly non-glacial agencies. Eliminating these, two classes of products of glacial waters working co-ordinately with the ice are recognized: those that gathered immediately within and beneath the ice-body itself, or against its margin; and those which were borne to distances beyond its limit by the glacial drainage or by peripheral waters. The products embrace a great variety of sub-types of gravel-heapings, including isolated mounds, conical peaks, clustered hummocks with inclosed pits and basins, and sharp, steep-sided ridges, often of phenomenal length, all possessing great irregularities of material and stratification, embracing frequently, manifest disturbances. The elongated variety, resembling the great osars of Sweden, are finely developed in Eastern New England; while the hummocky variety, constituting the ill-defined class of kames, are abundant throughout New England, New York, Northern New Jersey, Pennsylvania, Ohio, Indiana, the greater part of Michigan, Northern Illinois, Eastern and Northem Wisconsin, Northern Minnesota, North-Central Iowa, Eastern Dakota, and many parts of Canada. Of valley drift, attention was directed to the moraine-headed valley trains, and the loess tracts. The former show progressively coarser material toward their origin, and merge into expanded heads, blending with the moraines in which they begin. The broad tracts of fine silt, designated "loess," occupy the Mississippi up to East-Central Minnesota, the Missouri up to Southern Dakota, the Illinois and Wabash up to their great bends, and the Ohio up to Southeastern Indiana. Two other assorted deposits considered were those overspreading the great basin of the St. Lawrence and the Winnipeg basin. These often present, among their surest credentials, overflow channels to the southward, crossing divides sometimes hundreds of feet above existing outlets, and varying in altitude among themselves at least two thousand feet.


Durability of Water-Color Drawings.—A controversy, which recently arose in England on the durability of water-color drawings, led to an exhibition of pictures at which visitors were given opportunity to test for themselves the capacity of the specimens shown to hold their colors. The "Saturday Review" draws from the average of the works the conclusions that, in pictures or passages of especially vivid color, little in the way of fading need be apprehended; but, in the delicate, broad, and thin washes of the landscape-painter, "changes of various kinds are apt to take place, capriciously, as it would seem, and from various causes, of which long and continued exposure to light is probably one. Pending more accurate experiments, collectors and managers of public institutions will do well to keep their framed drawings rigorously protected from pure sunlight, and not exposed more constantly than is necessary to ordinary daylight; for which purpose they should be covered with blinds or curtains during the long hours of the summer mornings, and generally when the rooms in which they are hung are disused. Also it will probably be well to vary from time to time the drawings exhibited, and to return each occasionally for a period of rest to the drawer or cabinet. But on the question of frames versus portfolios, it has to be remembered that a well-framed drawing is secure at least from effects of atmosphere; while in portfolios it is only by extreme and constant care that risks can be avoided from dust and rubbing."


Marine Signals.—Sir James Douglass addressed the Section of Mechanical Science of the British Association on lighthouses and marine signals. There are at present not less than eighty-six distinctive characters in use throughout the lighthouses and light-vessels of the world; and as their numbers increase so does the necessity for giving a more clearly distinctive character to each light over certain definite ranges of coast. This important question of affording to each light complete distinctive individuality is receiving the attention of lighthouse authorities at home and abroad, and it is hoped that greater uniformity and consequent benefit to the mariner will result. There are now about seven hundred fog-signals, of various descriptions, on the coasts of the world; and their construction and operation have been the subject of careful experiment and scientific research. Unfortunately, the results thus far have not been so satisfactory as could be desired. This is owing partly to the very short range of the most powerful of the signals under occasional unfavorable conditions of the atmosphere during fog, and partly to the present want of reliable tests for enabling the mariner to determine at any time how far the atmospheric conditions are against him in listening for the signal. The question of utilizing lighthouses and light-vessels as signal-stations in telegraphic communication with each other and with a central station, has received the consideration of lighthouse authorities generally, and has been made of practical effect in Canada. Buoys are illuminated with compressed oil-gas; and automatic lighting apparatus has been applied to those in occasionally inaccessible positions. A comparative test of the merits of electricity, gas, and mineral oil, as lighthouse illuminants, carried on for twelve months, has given the following results: 1. That the oil- and gas-lights, when shown through similar lenses were equally affected by atmospheric variation; 2. That the electric light is absorbed more largely by haze and fog than either the oil- or the gas-light; and, 3. That all three are nearly equally affected by rain. The final conclusions of the committee are that for ordinary necessities of lighthouse illumination mineral oil is the most simple and economical illuminant; aud that for salient headlands, important land-falls, and places where a very powerful light is required, electricity oHers the greatest advantages.


Heredity and Education.—"Heredity and Education; their Relation to Each Other aud to the Human Race," is the title of an address by Dr. E. A. Wood, as President of the Pennsylvania Medical Society. The author holds very positive views on the subject, both as to the excellence to which he would have us aim to bring the race, and with regard to the means to be used to reach the end. "If such a man as Shakespeare," he asks, "has lived, why may not men as great as he live again; and if one man attained this greatness, why may not the average man? If the old Greeks reached such perfect development, why may not Americans? Is it possible that we have reached the zenith of our possibilities? Is it not rather probable that Shakespeare approximated but did not attain the possible average of human development? . . . Nature has written all over her page that Newton and Shakespeare were not accidents, but advance heralds, proclaiming the coming man. No man can conceive of the latent potentiality of the human race; by right effort continued in the right direction, man may be developed into a being grander than I his loftiest ideals." Further: "Let it be written that many races of men have improved, are improving, and bid fair still further to improve; but man has not improved in accord with his powers and opportunities, has not reached the standard of excellence reached two thousand years ago, and is not improving so rapidly as are the animals domesticated by him. The first step toward race improvement must be to teach our children that reproduction is the highest and noblest function of the animal. We are losing time by not teaching this lesson, and all implied by it, immediately and thoroughly."


The Future of the Supply of Plant-Food.—Vice-President Wiley began his address before the Chemical Section of the American Association—which was on "The Economical Aspect of Agricultural Chemistry"—with a rough estimate of the money value of the potash, phosphoric acid, and nitrogen contained in a single harvest, the total of which he placed at $3,343,786,050. This seems to be an enormous quantity of plant-food to be removed from the soil annually, but it must be remembered that it is not all lost; much of it is left in the soil in roots, straw, stalks, etc. But too often the débris is got rid of as quickly as possible, and we have in practice not tilling but killing the soil. The stores of plant-food which have accumulated in our virgin soils are indeed great, but they can not withstand this constant drain upon them. The potash that is in the soil may be estimated as enough to last two hundred and fifty years, and the phosphoric acid two hundred and twenty-five years. Immense reserves of both substances are, however, existent and accessible—the potash in feldspathic rocks, and phosphorus in the phosphate-beds. Still, the exportation of agricultural products becomes a slow but certain method of securing soil exhaustion. In point of fact, however. Professor Wiley further showed, the impoverishment of the soil takes place at a much slower rate than the theory announced above would indicate. Doubtless, much reserve food is brought from the subsoil, and, if it be possible for the subterranean stores of these materials to gradually work their way surface-ward, even the remote future need not fear a dearth of them. There is also a certain conservatism in crops, a vegetable "good breeding," which prevents the growing plant from taking all the food in sight. As long as there is abundance, the plant is a hearty eater; but, when the visible quantity of food falls to a certain minimum, it remains for a long time without any rapid diminution. Respecting the nitrogenous food of plants. Professor Wiley presented a series of studies from which the following conclusions were drawn: 1. The combined nitrogen, which is the product of vegetable and organic life, forms the chief source of nitrogen for the growing plant. 2. Before it is assimilated by the plant, it undergoes a process of oxidation which is due solely to a living organism. 3. The nitrates thus formed are absorbed by the plant, and the albuminoids of the new growth are formed from the nitric nitrogen by a process of reduction. The nitrates themselves are subject to the action of a ferment by which a deoxidation takes place, and free nitrogen and nitrous oxide are evolved. 4. The diminution in the quantity of available nitrogen thus supplied is restored by the fixation of free nitrogen, by the action of organisms in the soil, or by the oxidation of free nitrogen by the interior cells of the plant acting in a manner analogous to the nitric ferment in the soil, or by the oxidation of free nitrogen by electrical discharges or by combustion. 5. The quantity of combined nitrogen brought to the soil and growing plant by the rain-water and the atmosphere, arising from the last two phenomena, is an inconsiderable amount when compared with the whole weight required by the crop. Concerning the future food-supply, Professor Wiley said: "Since, with a proper economy, the natural supplies of potash and phosphoric acid may be made to do duty over and over again, and last indefinitely, the economist, who looks to the welfare of the future, need have no fear of the failure of these resources of the growing plant. Indeed, it may be said that the available quantities of these may be increased by a wide practice of agriculture based on the teachings of agricultural chemistry. But with the increase of population comes an increased demand for food, and therefore the stores of available nitrogen must be enlarged to supply the demands of the increased agricultural product. It is certain that with the new analytical methods, and the question raised by the investigations, many series of experiments will be undertaken, the outcome of which will definitely settle the question of the entrance of free nitrogen into vegetable tissues. If this question be answered affirmatively, agricultural science will not place bounds to the possible production of foods. If the nitrifying process goes on within the cells of plants, and if living organisms do fix free nitrogen on the soil in a form in which at least a portion of it may be nitrified, we may look to sec the quantities of combined nitrogen increased pari passu with the needs of plant-life. Thus, even intensive culture may leave the gardens and spread over the fields, and the quantities of food suitable for the sustenance of the human race be enormously increased."


Evolution of Means of Defense.—Mr. Charles Morris, in a paper of the Academy of Natural Sciences of Philadelphia, on "Attack and Defense as Agents in Evolution," suggests that the various modifications which are seen in the hard parts of animals at different periods indicate adaptation to dominant ideas that have different relations to the prevailing conditions of existence of the time. The earliest animals were probably wholly soft, and have left no remains except an occasional track on the mud of their day. Then came in armored forms with external shells. Swift-swimming armored animals came in with the fishes, and seem to have increased in thickness and weight of armor to the end of the Devonian era. "If, now, we come down to a later era of life, we find in operation what seems a third idea of Nature. The prevailing tendency in animal life is no longer to assume armor, but to throw off armor, and return toward the unprotected condition. The causes of these changes are related to the development of weapons of assault in attacking animals, and to the kind of defense that was most available and useful, or most eflicient at the period. As Mr. Morris says: "In the primeval epoch it is probable that only soft-bodied animals existed, and the weapons of assault were the tentacles, the thread-cell, the sucking-disk, and the like unindurated weapons. At a later period armor became generally adapted for defense, and the tooth became the most efficient weapon of attack. Still later, armor was discarded, and flight or concealment became the main method of escape, and swift pursuit the principle of attack, while claws wore added to teeth as assailing weapons. Finally, mentality came into play, intelligence became the most efficient agent both in attack and defense, and a special development of the mind began. As a culmination of the whole, we have man, in whom mentality has replaced all other agents in the struggle for existence. But, side by side with man all the other types exist, the soft-bodied, the armored, the swift-moving, and those in which cunning precedes the higher mentality. In the existing conditions of life upon the earth we have an epitome of the whole long course of evolution."


Acclimatization of Deer.—Viscount Powerscourt has communicated to the Zoölogical Society of London the results of his experiments in acclimatization, conducted since 1858 and 1859, on his estate in Ireland, of foreign deer. He had at one time alive in a park of one hundred acres, about two thirds of which was open pasture and one third wood, red deer, Sambur deer, Nylghaies, axis deer, llamas, elands, wapiti deer, and moufflons, or wild sheep. The red deer increased and the wapiti bred, but the Nylghaies died while still apparently in good health. Accidents interfered with the success of the experiments with the wapitis, but the results, taken in connection with experiments made elsewhere, indicated that the acclimatization of these deer will be entirely practicable. The Samburs declined, and died in the course of three or four years, because, apparently, they insisted on staying in the shade. The elands, axis, and llamas died, or proved so delicate that they had to be taken away. The most favorable results were obtained with Japanese deer (Cervus sika), which throve excellently and multiplied without requiring other than the ordinary winter feeding. They are pronounced, after twenty-four years of breeding and increase, "a most satisfactory little deer; the venison when dressed is about the size of a Welsh mutton, and well flavored."


Longevity of Great Men.—In a paper read at the American Association, on "The Longevity of Great Men," Mr. J. Jastrow observed that all that the usual method of attempting to answer the question whether great men are longer lived than others can prove is that it takes long to become great. It neglects to consider that a select class of men is dealt with, and that to become potentially included in this class one must have lived a certain number of years. A review of a list of greatest men appeared to show that, on the average, a man must be thirty-seven years old in order to be a candidate for a place in this list. Comparing the ages to which such men live with the average expectation of life of men at thirty-seven, the author inferred that men of thought live three years longer, while the lives of men of feeling are three years, and those of men of action five years shorter than those of ordinary men—a conclusion which is somewhat different from the commonly accepted view on the subject. The question of longevity becomes important when we consider that through it the leaders of thought are allowed to exercise their important function here a few years longer, so that more great men are enabled to be alive at the same time. By the rule of heredity also, the children of great men will begin life with a better chance of reaching maturity and an age when they may become important to the world.


Evils of Undiscriminating Charity.—It is asserted by a clergyman residing in one of the districts where the most good was attempted to be done by its distribution, that the Mansion House charitable fund of London has done a vast amount of mischief in those very districts. This clergyman, Mr. Barnett, Vicar of St. Jude's, treats the fund as a calamity which has befallen London, not less, perhaps even greater, than the distress for which it was supposed to be the remedy. The evil arises from the failure to exercise discrimination in the administration of a bounty which, properly applied to the proper persons, might be made of great benefit. The failure in this case to accomplish an object designed to be good leads the "Spectator" to indulge in some remarks on the mischievousness of undiscriminating good feeling in general. There is hardly a single good feeling, it says, however just and praiseworthy in its kind, which men can simply indulge without incurring the greatest danger of doing harm. There is, for instance, the lavish habit of bestowing praise and blame in immeasured volume, under the dictation of mere impulse. "We see men and movements praised up to the skies which are full of dubious elements, half evil and half good, and other men and other movements as passionately censured which, again, are full of the same double character, half good and half evil. . . . The result undoubtedly is, that we give sympathy in the gross where only discriminating sympathy would be beneficial, and blame in the gross where only discriminating blame would be beneficial. And, as a natural consequence, we hatch all sorts of unhealthy eagerness to do what either ought not to be done at all, or else ought not to be done except by very carefully selected people, and all sorts of equally unhealthy eagerness to run down modes of action which in the right hands may be wise and good, though in the wrong hands they are pernicious in the highest degree."