Popular Science Monthly/Volume 29/June 1886/Popular Miscellany

From Wikisource
Jump to: navigation, search


How the Oyster makes his Shell.—Professor Samuel Lockwood, in a recent lecture before the New York Microscopic Society, answered the question which is asked by the fool in "King Lear"—"Canst thou tell how an oyster makes his shell?" He starts with the hinge-end, at the spot known to conchologists as the umbo. "A small plate, or single scale, now represents each valve, and that is the first season's growth. The next season a new growth, or plate, shoots out from underneath the first one, just as shingles do. The oystermen call these laps, or plates, 'shoots,' and they claim that the number of shoots indicates the years of the oyster. They certainly do contain a record of the seasons, showing the slow-growing and the fast-growing seasons. ... I have likened these shoots to shingles. Now, at the gable of a house the shingles may be seen edgewise. So on the side of an oyster-shell is a series of lines. This is the edge-wise view of the shoots, or season-growths. Another factor is the purple spot, or scar, in the interior of the shell. It is the place of attachment of the adductor muscle. Its first place of attachment was close up to the hinge. Had it stayed there until the shell had become adult, how difficult would be the task of pulling the valves together!—the leverage to be overcome would be so great; for we must bear in mind the fact that at the hinge-end the valves are held by this black ligament, which is, in life, elastic, swelling when the shell opens, and being compressed when the animal draws the valves together. So, with every year's growth, or elongation of the shell, the mollusk moves the place of attachment of the muscle onward, that is, in advance farther from the hinge. As it does so, it covers up with white nacre all the scars that are back of the one in actual use as the point of attachment of the muscle." To make the similitude of the oyster's shoots, or season-growths, with the shingles on a roof complete, "it would be necessary for the bottom shingle on the roof to underlie the whole series, and reach even to the roof-tree, or ridge-pole. Then the second shingle from the gutter must in like manner underlie all the rest of the series; so of the third, and so on with the rest. In this way lie the shoots, or laps, of the oyster's shell. The last one deposited underlies them all, and every one terminates at the channel in the bill—so that this groove in the bill contains a series of transverse lines, each one marking a season, or a year. Thus we get really four factors for the solution of the question, 'How old is the oyster?' all of which are the outcome of the method or way of making the shell."

The Trap-Dike of Southeastern Pennsylvania.—Professor H. D. Rogers, in his report for 1858 on the geology of Pennsylvania, refers to two trap-dikes in the southeastern part of the State. In the map published in connection with Professor J. P. Lesley's survey, Mr. C. F. Hall connects the two dikes so as to make a single dike about eight miles long. Professor H. Carvill Lewis, after two years of observations, has found that this dike is only a small part of a long, narrow dike, which passes almost entirely across the southeastern part of Pennsylvania, from near Doylestown to Maryland, and which, taken together with some parallel dikes of similar nature and composition, northeast of Doylestown, forms a series of nearly continuous dikes some ninety miles in length. In the paper he has published on the subject he shows that, although frequently represented only by a line of loose weathered bowlders, it is prac- tically continuous along a course seventy miles in length. In Bucks County the dike abuts against the south side of a great fault of several thousand feet upthrow, and up- ward of twenty miles in length, while, at a distance laterally of five miles, another long dike of identical composition and structure abuts against the north side of the fault, and continues thence to the Delaware River. If not the same dike laterally displaced, the two portions clearly belong to the same system, and were produced by a single cause. It is said that this dike was used during the war of the rebellion by the negro slaves as a guide in their flight northward. Several of the stations of the underground railroad are said to have been on or near its line; and the negroes were directed to follow these black rocks across fields and through woods "until they were led into the hos- pitable regions of Chester and Bucks Coun- ties."

The Magnitude of Dr. Gould's Astronom- ical Work. At the complimentary dinner given to Dr. B. A. Gould in Boston, in May, 1885, Professor W. A. Rogers, of Harvard Observatory, made a suggestive comparison of the work which Dr. Gould has done at Cordoba, in the Argentine Republic, with similar work done previous to 1S72. There are, he said, in the northern heavens about 4,500 stars visible to the naked eye; while within the same limits there are about 95,000 stars as bright as, or brighter than, the ninth magnitude, which are usually ob- served in narrow belts or zones, and are referred to as zone-stars. The bright stars are common to nearly all general cata- logues, but the positions of the fainter stars depend, for the most part, on two or three separate observations. Dr. Gould has formed two catalogues since 1872 a gen- eral catalogue of stars extending to the south pole, containing 34,000 stars, and a

catalogue of zone-stars, numbering 73,000. The two catalogues represent about 250,000 separate observations. It is stated in one of the printed .volumes that the chrono- graphic register of the transits, the point- ing of the telescope for declination, have all been done by Dr. Gould personally. The number of distinct and separate ob- servations involved in this work must cer- tainly exceed a million. The whole num- ber of stars in the two Cordoba catalogues is nearly three times as great as in any single catalogue thus far constructed; and it must be remembered in this connection, that the great catalogues of Lalande, of Bessel, of Argelander, and of Schjellerup, represent the labors of a lifetime. The total number of stars in all catalogues formed previous to 1870 is about 260,000, as against the 105,000 stars in the Cordoba catalogues. Since 1869, a confederation of fourteen observatories, situated in different parts of the world, has been engaged in the accurate determinations of the positions of the 100,000 stars to the ninth magnitude in the northern heavens. Up to 1882, a total of about 346,000 observations had been made. Considerable progress had been made in this work before Dr. Gould left this country for South America. His work, involving two thirds as many observa- tions as all others combined, is completed, and is all in the hands of the printer, while the actual formation of the catalogue to be issued under the direction of the Astro7io- mische Gesellschaft can hardly be said to have been begun.

Japanese Camphor. Camphor is very largely exported from the Japanese island of Kiu Shiu, where the tree grows abun- dantly in all situations. Many of the trees reach a great size, some near Nagasaki be- ing said to be ten or twelve feet in diame- ter, while at other places are trees measur- ing twenty feet across; after forming a trunk twenty or thirty feet high without limbs, the tree branches out in all direc- tions, forming a well-proportioned and beau- tiful evergreen mass. The leaf is small, elliptical, slightly serrated, and of a vivid dark green. The berry grows in clusters, and resembles a black currant. The wood is valuable for cabinet-work and for purposes of ship-building. The tree is neces- sarily destroyed in the manufacture of cam- phor, but the law requires a new one' to be planted in the place of every one taken away. The gum is extracted by distillation from the chips, the whole tree being cut up for the purpose, and steamed in a tight ves- sel or box. The steam, camphor, and oil, the immediate products of the process, are conducted through a bamboo tube to a sec- ond tub, and from this to a third, which is divided into an upper and a lower compart- ment. The partition between the two di- visions is perforated with small holes to allow the oil and water to pass to the lower compartment. The upper compartment is supplied with a layer of straw, which catch- es and holds the camphor in crystals. The camphor is then separated from the straw and packed in wooden tubs containing a picul, or one hundred and thirty-three and one third pounds, each, for the market. The oil is used for illuminating and other purposes. The exports of camphor from Nagasaki in 1882 were valued at $290,000.

Protect the Birds. The Committee on Protection of Birds of the American Or- nithologists' Union has begun the issue of circulars, calling attention to the threatened danger of the destruction of our native birds by the greed of specimen-collectors, milliners, egg -hunters, and Vandal sports- men. A paper by Mr. J. A. Allen, in the first "Bulletin," gives an estimate of the alarming extent to which this destruction is going on. The conditions of modern life are in themselves furnishing what we might now call natural agencies that is, sponta- neous and of constant operation which contribute more, perhaps, than all pre- viously operating natural agencies com- bined to limit the increase, or, perhaps, diminish the numbers, of birds. To these may be added the growth of a passion for hunting birds for various purposes and sometimes under mistaken views, which has become so violent that it is almost a won- der that any birds are left. Collectors ap- pear to be charged with a larger share of responsibility in this matter than notwith- standing there is vastly too much reckless collecting they deserve. Mr. Allen calcu- lates that the number of birds killed for

their purposes since collecting began does not exceed 500,000; while, to gratify the vanity of the "dead-bird-wearing gender" of the human race, not less than 5,000,000 are sacrificed every year! Mr. George B. Sennett, in a paper in which he tells how the pelicans were exterminated from an island off the coast of Texas in an experi- ment at making an oil from them which proved to be worthless, says that "if a tithe of the truth were known throughout the country at large concerning the sacrifice of bird-life in the names of l business,' ' en- terprise,' ' food,' ' sport,' and what not, from Maine to Mexico, and from California to Alaska, there would be such a cry of remonstrance as would make the bird-de- stroyers hang their heads for shame " that is, if there is any shame left in persons capa- ble of engaging in such business. By far the largest numbers of birds are slaughtered to supply ladies' hats; and it is for the ladies themselves to apply the remedy for the evil, by refusing to wear such barbaric ornaments. Noble women in this and other countries are organizing to put down the iniquitous fashion. The object deserves universal support.

Professor Pickering's Telephone. In

a paper read by him before the Ameri- can Academy of Arts and Sciences, on his "Early Experiments in telegraphing Sound," Professor Edward C. Pickering showed that in 1870, several years before the telephones now in use were invented, a receiver was devised, constructed, and tried, which consisted of a flexible iron diaphragm, supported at the edges and re- placing the armature of an electro-magnet. Musical sounds were telegraphed success- fully, and the apparatus was described at a scientific meeting, of which a report was published in the "Troy Press" of August 24, 1870. In 1872 and later, the experi- ment was repeated under various condi- tions. In 1879 it was shown that the in- strument was capable of serving as a tele- phone, and of rendering articulate speech audible at a distance. It appeared to differ in no way in principle from the receiver now used. Professor Pickering explains, however, that all his experiments were made, or were intended to be made, with a discontinuous current, and, although the instrument is capable of showing the vari- ations of a continuous current, the author did not have this application in mind when he constructed it. No patent was taken out for the device, for the inventor believed that "a scientific man should place no re- strictions upon his work which would tend to prevent the repetition of an experiment of scientific interest. A full description should have been published. This was at first delayed, from the pressure of other work, and lack of appreciation of the im- portance of the results. Afterward I was unwilling to enter into a controversy, or to obstruct my friends, who were struggling to obtain proper recognition of the great re- sults they had obtained in the same field."

What Ice can do# The important part in producing or modifying topography that has hitherto been conceded to moving mass- es of ice has recently been disputed by some American geologists, who have denied that ice possesses any eroding or excavating pow- er. Professor J. S. Newberry has published an article sustaining the old theory against these contradictions by evidences drawn from the visible action of living glaciers, as in the Alps, and also in the mountains of Oregon, where a remarkable monotony of surface has been produced by ice-action. The crest of the Cascades, crowned by the volcanic peaks, Mount Jefferson, Mount Hood, etc., has sides sloping east and west, like the roof of a house. These slopes are planed down, and their asperities removed, everywhere showing the effects of a powerful grinding agent. In the Laurentian belt north of the lakes, where were formerly high mountains, are now only low hills and rolling surfaces, and the strata are "standing at high angles but planed down, scratched and ground by glaciers, until their cut edges are like boards in a floor." Similar work has been performed between the Hudson and the Connecticut. The action of running water on topography is not only different from that of ice, but antagonistic to it. Water deepens the lines of drainage and increases the asperi- ties. The canons of the Colorado are typi- cal and characteristic illustrations of water- action on continental surfaces. Great ice- sheets, on the contrary, tend to reduce all

asperities, fill depressions, and render the topography monotonous. If ice is compe- tent to do the work of shaving and smooth- ing the landscape, which the author aims to prove by his citations that it has done, much more may it have excavated lake -basins. " The power which has done the greater is certainly equal to the less." Probably, Pro- fessor Newberry adds, some misapprehen- sion arises from an inadequate conception of the composition and action of a glacier. " It is, perhaps, regarded as a mass of pure ice, which by itself would have little grind- ing power; but a glacier is a great moving mass which by its weight and motion crush- es and removes all but the most solid rock prominences over which it passes. Where it impinges against cliffs, these are some- times lifted, and huge blocks are carried away. In many localities we find stones hundreds of tons in weight, which have been torn from their beds and carried many miles. Pure ice, then, in sufficient volume is a potent and almost irresistible agent of erosion, quite independent of its grinding action; but, as a matter of fact, all glaciers are studded below with rock - fragments, great or small, which they have torn up in their course; so that sand, gravel, and bowlders constitute a coating to the under surface of a glacier which may be compared with the emery on a copper wheel."

Have we gone too far in draining Swamps? In one of a series of papers on " The Proper Value and Management of Government Timber-Lands," read at the De- partment of Agriculture, in May last, Mr. M. C. Read showed that harm rather than good has been done by the draining of the swamps which has been so vigorously pros- ecuted during the last twenty-five years. The swamps were constant store-beds and sources of moisture, and tended to keep the streams that drew upon them at an even level. In draining them, they being generally found on the same level as the surface of adjacent lakes, the outlets of the lakes were deepened so that they could be drained more speedily and completely. To accom- modate the more rapid outflow that accrued, the streams below were often straightened and cleared out, and the rapid concentration of the water into the larger streams was made as easy as possible. "All three agencies combined are making the surface- drainage almost a3 perfect as if a series of impervious roofs covered the land, and all the flow from them were conducted by pipes into one common channel." Consequently, " springs once copious have disappeared; streams formerly perennial alternately over- flow their banks and run dry. The natural regulators of the streams having been de- stroyed, whenever there is an excessive rain it is rapidly carried into the streams, which, gradually uniting their waters, often con- stitute floods in larger channels which no human appliances can control." Dike3 and levees will check the evil for a time, only to make it greater in the future. The only possible remedy for all these evils is "to hasten as quickly as possible to undo our work and recreate the natural reservoirs we have destroyed. By reforesting the swamps and the higher land which surrounds them and the lakes," we shall restore them to their proper place in the economy of Na- ture." The lakes should be restored to their former dimensions, and enlarged wherever practicable. A scheme kindred to this is that of creating artificial reservoirs at the sources of rivers, as at the sources of the Ohio in the Alleghany Mountains, by dam- ming up the ravines of the smaller streams.

Earth-Contraction and Mountains. Mr. William B. Taylor lately read a paper before the Philosophical Society of Washington before which he suggested that the crumpling of the earth's crust, with the formation of mountain-ranges, was a result of modifica- tion in the spheroidity of the globe pro- duced by a change in the length of the day, which change is an effect of the re- tarding action of the tides. It is established, in the author's mind, as beyond a reason- able doubt, that our present day is consider- ably longer than the day of early geological times. Supposing the equatorial radius of the earth to have been once one tenth greater and the polar radius one tenth less than they are now, it is evident that, from the very slow but never-ceasing contraction of the equatorial shell, due to diminution of rotatory motion, " this crust would be sub- ject to an unremitting stress of lateral com- pression as relentless as that from the old

hypothetic shrinkage of volume by reduc- tion of temperature. Is it not precisely this morphologic contraction whose effects and records are everywhere apparent in the crumpling of the earth's crust? "On this view the facts may be explained that the circumpolar regions, where the crust has, by the theory, been stretched, are relatively free from mountains or plications, while the intertropical region contains the highest ele- vations. So strongly impressed is Mr. Taylor 11 with the inevitable operation and potency of this unquestioned retardation of rotation that, were all traces of any differential action masked and obliterated, he would still hold to it as the one efficient cause to account for the prominent constriction of the crust displayed in every land. But the differen- tial traces of oblateness have not been ob- literated masked though they may be, to some extent, by other perturbations." From various conditions, he adds, "we may infer that in all geological ages the progress of elevation has been in excess of that of degradation by erosion; that in all ages mountain-building has been at a maximum; that is, that the uplifted heights have been the greatest which the average thickness of the crust at the time was capable of sup- porting; so that the former has been a constant function of the latter, the ratio being probably not far from one fifth." The increasing maximum of elevation has probably now reached its limit, for both the processes of equatorial contraction and of internal temperature reduction are going on with extreme and lengthening slowness; " and the whole remaining subsidence of the intertropical oblateness can not exceed five miles, during the vast ages in which the earth's rotation shall be entirely arrested."

Snake-Poisoning. Dr. G. C. Roy, con- trasting the physiological action of snake- poison and the symptoms of rabies, has made the suggestion that the venom of the cobra might be tried to counteract the mor- bid phenomena of rabies. An interesting compendium of facts respecting snake-poi- sons has been published in Calcutta by Mr. Vincent Richards, from which we learn, among other things, that we have no anti- dote to the poison when it has once fully entered into the system. If the venom can be confined to a part, by means of a liga- ture, then permanganate of potash, in a five per cent solution, is an efficient destroyer of its power. Ammonia is not a remedy. Some seeming cures may be accounted for by the fact that, if an insufficient dose of the venom be administered, the bitten ani- mal will live, whether stimulants alcohol or ammonia be given or not. The intel- lect does not appear to be affected by snake- poisoning, but remains unclouded to the last.

Turquoises. The turquoise, in the mid- dle ages, was accredited with even more supernatural virtues than were ascribed to other precious stones. The wearer of it had his sight strengthened and his spirits cheered; if he fell, the gem would break instead of his bones, and save them; and, if he became sick, it turned pale. When its possessor died, it lost its color, to recover it again on passing into the hands of another. In some mysterious way, when suspended by a string, it was capable of correctly striking the hours on the inside of a glass vessel. Turquoise a hydrated phosphate of alumina colored by traces of com- pounds of copper and iron may be of va- rious colors of blue and green, but only the fast sky-blue specimens are prized as pre- cious stones. The other shades may be imitated in inferior stones, this one not. The material of some fossil teeth is capable of being colored with phosphate of iron so as to resemble real turquoise, when it is called odontolite or Occidental turquoise, but it is softer than the genuine Oriental stone, and thereby easily distinguishable from it. Jewelers' turquoises come from the mount- ains of Khorassan in Persia. A very sat- isfactory report upon the mines has been furnished the British Foreign Office by Mr. A. H. Schindler, who was for a short time director of them. The veins occur in the met amorphic strata, with which the num- mulitic limestone of the mountains is mot- tled, and are very ancient and extensive, bearing frequent evidences of the old work- ings. The mines are quite deep, one of them reaching down to one hundred and sixty feet. The works are carried on by the people of the villages, who are careless in management, and improvident. At the

mines, the turquoises are roughly divided into three classes, of first, second, and third qualities. All the stones of good and fast color and favorable shape belong to the first class. But they vary most curiously in value, for Mr. Schindler says, "it is im- possible to fix any price, or classify them according to different qualities. I have not yet seen two stones alike. A stone two thirds of an inch in length, two fifths of an inch in width, and about half an inch in thickness, cut peikani (conical) shape, was valued at Meshed at three hundred pounds; another, of about the same size, shape, and cut, was valued at only eighty pounds. The color most prized is the deep blue of the sky. A small speck of lighter color, which only connoisseurs can distinguish, or an almost unappreciable tinge of green, de- creases the value considerably. Then there is that undefinable property of a good tur- quoise, the zdt, something like the ' water ' of a diamond or the luster of a pearl; a fine colored turquoise without the zdt is not worth much." The stones are cut in three ways the flat or slightly convex form, the truncated cone, and the tallow-drop or en cabochon. The higher the conical and con- vex surfaces in the two latter, the more the turquoises are prized. None but a fine, deep-colored stone can be advantageously cut into a conical shape, since one of a pale color would appear almost white at the apex. Some mines contain stones which look well at first, but soon change their color and fade. These, of course, are worthless.

Poisons formed from Food. The subject of "Poisons formed from Food, and their Relation to Biliousness and Diarrhoea," has been considered by Dr. T. Lauder Brunton in articles in "The Practitioner." There are persons, he says, or even, perhaps, 11 classes of people," to whom even articles of food, usually salutary, are poisonous. Many articles of food, also, have a property of splitting themselves up so as to yield poisons. The melon and cucumber tribe of vegetables exhibits a tendency to the for- mation of purgative substances. In animal foods poisonous properties are apt to appear either from particular modes of cooking, or from beginning decomposition. The decomposition may be effected by microbic organ- isms, or by the digestive ferments of the healthy body; and they are various accord- ing to the particular organism or ferment that sets them up, and according to the tem- perature at which they occur, and the length of time that they continue. Some of the products of decomposition are poisonous in various degrees of activity, while others are innocuous. When kept separate, the poison- ous products remain unchanged for a long time, but when mixed together they are apt to undergo further decomposition and be- come inert. Besides temperature, the de- gree of moisture in the subject of decom- position or in the atmosphere, and electrical conditions as when milk is " soured by thunder "exercise modifying influences, which have not yet been definitely ascer- tained. The difference between the prod- ucts of decomposition in hot and cold weath- er is illustrated by the alkaloids obtained from decomposing maize in summer and winter. The winter alkaloid has a narcotic and paralyzing action; but in summer an- other alkaloid is also yielded, which has a tetanizing action something like strychnine. On account of the greater rapidity of the putrefactive process, albuminous substances become poisonous much sooner in summer than in winter, and again lose their poison- ous properties more quickly by further de- composition. As putrefaction may go on to a certain extent after the introduction of food into the intestinal canal, poisons may be formed from the part eaten, and pro- duce dangerous symptoms, while no poison can be found in the remaining parts of the same food.

The Hypothetical Planet Neith. Seven times since the invention of the telescope a lesser body has been observed near Venus in such a situation as to suggest that it might be a satellite of that planet. The ob- servations can hardly have been illusive, though they were only fleeting ones, for they were made by skilled astronomers. The last one was in 1764. M. J. C. Houzeau, of the Brussels Observatory, has examined the data of them in an endeavor to deter- mine the nature of the body. They do not agree with the supposition that it is a satel- lite, or that it is an intra-Mercurial planet.

They are consistent, however, with the sup- position that it moves in an orbit about equal to or a little larger than that of Venus, with which it comes in conjunction at in- tervals which are multiples of a little less than three years; for the intervals between the observations all represented such mul- tiples. Supposing the observations to be correct and to indicate the real existence of such a body, M. Houzeau proposes for it the name of Neith. The search for this planet would furnish good occupation for amateur astronomers.

Causes of Financial Stringency. The

" Edinburgh Review "ascribes the present general monetary scarcity to the vast expan- sion of trade since the middle of the centu- ry, which was in great part an effect as well as an accompaniment of the new supply of gold that came in at that time; the decline which has taken place in the yield of the gold-mines; and the large augmentation in the demand for gold which has been occa- sioned by the extensive demonetization of silver. The influence which the large addi- tion to the world's stock of specie since 1848 has exerted upon the value of money, though important, has been by no means so great as was expected." The doctrine that changes in the amount of the circulating medium are really of no consequence, inasmuch as such an increase is pari passu attended by a pro- portionate change in the value of money, so that the effective power of the currency re- mains unaltered, is now all but extinct, and can survive only in minds which are imper- vious to the remarkable lessons of the last thirty years," which have "demonstrated afresh the correctness of the old and com- mon-sense view of the matter namely, that if there is an increase of business operations, or other effective requirements for money, a proportionate addition to the currency will only serve to keep the value of money at its previous level; and, if trade or these monetary requirements increase faster than the amount of currency, prices will fall (or the value of money will rise), however large the annual additions to the currency may be. More remarkably, and on a far grander scale, the same truth or principle was illustrated in the history of the three centuries which followed the discovery of the New World." In 1850 sixteen millions sterling of specie annually did less for the wants of the world than ten millions had done in 1810, and much less than two mill- ions had done nearly three centuries pre- viously, in the reign of Queen Elizabeth. " Whenever the supply of money becomes stationary in the civilized world, or in a progressive community, prices begin to fall, owing to the steady increase of population and monetary requirements. Thus, . . . during the silver age, although the annual production of the precious metals increased continuously throughout three hundred years well-nigh doubling in each succes- sive century the monetary wants of the world increased quite as fast, and ere long began to outstrip the growth of the mone- tary supply." A careful analysis of the statistics of coinage and other uses, and of the supply of the precious metals, based upon the reports of the Director of the United States Mint, shows that "the cur- rent requirements for coinage of themselves exceed the total annual supply of the pre- cious metals by four millions sterling, while the consumption in the arts amounts to nine- teen millions indicating a reduction, or at least an inadequate supply, of metallic mon- ey to the extent of twenty - three millions annually." The disastrous effects of a mon- etary dearth are extensive. It affects not only current trade, but real property, or fixed wealth of all kinds. The value of money is rising, and consequently the sale value of all other commodities is falling. Even the moneyed class lose also, owing to the low rate of interest and the lack of re- munerative kinds of investment; but agri- culture is most affected by a change in the value of the circulating medium, because such a change comes upon it with di- rect and unbroken force. Thus, the mis- chief works round the whole community, or indeed the civilized world. No human power can prevent the embarrassment aris- ing from an inadequate production of the precious metals. "But, fortunately, the source of our present difficulties is no longer the mystery that it was, even to statesmen in former times. The fact that nowadays it can be traced to its fundamental causes constitutes the best hope amid our present difficulties."

Is Tea-drinking salntary? The Dean of Bangor has charged tea-drinking with destroying the calmness of the nerves, mak- ing people uneasy and irritable, and acting as a dangerous revolutionary force. Some medical men, including American doctors

and Dr. Richardson,

agree with him;


Dr. Gordon Stables has pronounced tea "the drink of pleasure and health," and has ex- pressed the opinion that it ought to be the national drink of England. The general current of public opinion and practice ap- pears to be favorable to the latter view. In the British army, says the "Pall Mall Gazette," the use of tea is slowly but surely supplanting the use of grog. The soldiers who captured Tel-el-Kebir dr ank nothing but tea. It was served out to them three times a day, and they found it most pleasant and invigorating on the march. Its use among athletes and others who perform physical feats is becoming more general. The use of alcohol and tobacco is universally con- demned in the various hand-books on train- ing, but the use of tea is always recom- mended. To the charge that tea-drinking stimulates revolutionary tendencies may be answered that the greatest tea-drinking na- tion in Asia, the Chinese, is the most con- servative, and that the Russians, the great- est tea-drinkers in Europe, are the most stolid of Western peoples. Of great men, Dr. Johnson described himself as "a hard- ened and shameless tea-drinker." Kant used to breakfast on a cup of tea and a pipe of tobacco, and to work on them for eight hours. De Quincey usually drank tea from eight o'clock at night till four o'clock in the morning. Buckle was a most fas- tidious tea-drinker. William Howitt regu- larly took tea and coffee, and found the greatest refreshment in both; and Mr. Glad- stone is one of the greatest tea-drinkers of the century.

Variation in Earthquake-Vibrations.

Professor Milne, of Tokio, Japan, making a seismic survey of the ground near bis house, placed similarly constructed and test- ed seismographs at different places, but in similar positions. The result of observing many earthquakes was that all the instru- ments, the positions of which would be in- cluded within a triangle, the sides of which were eight hundred or nine hundred feet in length, gave different indications as to direction, amplitude, maximum velocity, and intensity; so that, had these instruments been in the hands of different observers, each observer would have given a different account of the same earthquake. Thus, comparing the average maximum velocities at a station, C, on hard ground, with that at a station, E, on soft ground, they were found to be 1:5. The maximum accelerations at these two stations were 1:2·4. It might therefore be concluded that a building at C would withstand a disturbance which would be sufficient to shatter a similar building placed at E.