# Popular Science Monthly/Volume 25/October 1884/Popular Miscellany

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POPULAR MISCELLANY.
The Warmest Month.—M. E. Renou remarks, in the "Annuaire" of the French Meteorological Society, that throughout the northern temperate zone the maximum of temperature occurs, as a rule, in July. In the corresponding zone on the other side of the equator the maximum comes in January. Between these two zones, or at the equator, the epoch of maximum falls at various dates, according to the storms that rule in the region. They are not so important there as in the other regions, for the difference between the coolest and the warmest month is little at the most. A curious law seems. to prevail in the distribution of the maximum. In North America the warmest month is almost universally July; but in the southern regions of that continent it occurs in August. In the Antilles it may be looked for in September, and at Cayenne in October. Passing through South America, before reaching the latitude where it comes in January, we find countries where it occurs, in November and then in December. The maximum is found in January through all the southern part of that continent and in Chili. In Peru it occurs in March; there is, therefore, a region between Peru and Chili where it must be looked for in February. North of Lima it is found in April, and farther north in May. Finally, it comes in June as we approach Sonora, and in July in California, where we are brought back in the returning circle to our starting-point. Between Cayenne and Peru we shall evidently find places in which the maximum moves from October into November, etc., and at last into March. In the Gulf of Mexico we may also remark a rapid variation in the time of the maximum temperature as we go from east to west. A similar distribution, marked by the same peculiarities, is noticeable in the Old World. The ​march of the temperatures of both continents is marked by the analogous phenomena of a shifting of the month of the maximum from July to January in going from north to south on the eastern side, and from January to July in returning from south to north on the western side of the continent. The most rational explanation of the difference presented by the eastern and western coasts is to be sought in the differences in their positions in relation to the seas and to the distribution of storms.
The Earthquake of August 10th.—The Northern Atlantic section of the United States was disturbed on Sunday afternoon, August 10th, by a very distinct earthquake-shock, which, taking place in the city of New York, at about seven minutes past two o'clock, lasted for some ten or fifteen seconds. The shock was felt all along the seaboard from North Carolina to Maine, through a district of country about six hundred miles long and two hundred miles wide, the most distant point from the ocean where it was remarked being at Titusville, Pennsylvania. Its greatest force appears to have been along the Long Island and New Jersey coasts. The statements of the time of the observation of the shock vary some seventy-five seconds as between Boston and New York, so as to show that the general direction of its progress was from north to southwest. It was not accompanied or preceded by any observable peculiarities in atmospheric phenomena. No damage appears to have been done by it anywhere, beyond the occasional fall of a brick from a dilapidated chimney or the shaking down of some article that was not securely fastened, although the nervous excitement it occasioned appears to have been fatal to a few persons. At Boston, the signal-officer, taking his ease in the highest building in the city, was shaken off from his lounge. At Seabright, New Jersey, the railway-station was shifted to one side, with a "shaking up of the contents"; and other trifling incidents of no worse character were remarked in various places.
A Destroyer in the Spruce-Forests of Maine.—According to accounts of observations published in the third "Bulletin" of the entomological division of the Department of Agriculture, the ravages of the spruce-bud worm (Tortrix fumiferana) have been extensive and destructive in the coast forests of Maine west of the Penobscot River. The damage appears to have reached only a few miles inland from the coast, but the belt in which it has prevailed is marked by extensive masses of dead woods. The trees are attacked in the terminal buds, which are eaten away, and, when that is done, the case is hopeless. The fatal character of the attack is owing to the fact that the spruce puts forth but few buds, and those mostly at the end of the twigs, and, when these are destroyed, it has nothing on which to sustain the season's life. The attack is made in June, when the growth is most lively, and just at the time when the check upon it can produce the most serious results. The larches are also attacked by a saw-fly, but with results that are not as necessarily fatal as in the case of the spruce. They are more liberally provided with buds, some of which may escape and afford a living provision of foliage. The larch, moreover, sheds its leaves in the fall, and is in full foliage before its enemies attack it. Hence, while the spruce and fir succumb to the first season's assaults, the larch can endure two years of them.
The Greely Arctic Expedition.—The vessels sent out for the relief of Lieutenant Greely and his Arctic Expedition returned to St. John's, Newfoundland, July 17th, with the report that they had, on the 22d of June, rescued from their quarters in Camp Clay, Cape Sabine, near the entrance to Smith Sound, seven of the members of the expedition, the other eighteen members having died during the present year, of starvation and exposure. One of the rescued men. Sergeant Elison, died a few days later, after the amputation of his frozen feet. All the records of the expedition were saved, and are to be published. They show that its work was of the most creditable character, and was fruitful in scientific results. Lieutenant Greely's party was sent out by our Government in 1881, as one of a series of International Arctic Expeditions, on the plan suggested by Lieutenant Weyprecht, of the Austrian service, for establishing permanent stations as far ​north as possible, whence advance parties might be sent farther toward the pole. In the summer of 1882 it established a station at Fort Conger, north of Lady Franklin Bay, near the eighty-second degree of latitude, which it abandoned in August, 1883, to come down to Cape Sabine. Of the exploring parties sent out, one, under Lieutenant Lockwood, reached in Lockwood Island the highest latitude yet attained -83° 24·5' and longitude 40° 45', and went a short distance beyond. From a height of two thousand feet, Lieutenant Lockwood discerned in the northeast Cape Robert Lincoln, latitude 83° 35', longitude 38°. Lieutenant Greely, exploring Grinnell Land, discovered Lake Hazen, some sixty miles by ten miles in extent, and ascended Mount Arthur, five thousand feet high. In a subsequent exploration by Lieutenant Lockwood and Sergeant Brainerd, Grinnell Land was found to be bounded by a water, named Greely Fiord, across which was discerned another land, to which the name of Arthur Land was given. The northern and southern parts of Grinnell Land appear to be covered with ice-caps, between which is a belt of open country some sixty miles wide. Hayes Sound was found to extend some twenty miles farther to the west than is shown on Sir George Nares's chart. The lowest temperature observed was 61° below zero. Animal life was abundant around Fort Conger, but scarce on Cape Sabine. The details of the sufferings and privations to which the party were exposed on Cape Sabine, in consequence of the failure of the supply expeditions to deposit stores of provisions where they were expected to be found, are extremely painful.
Relation of Springs and the First Settlements of a Country.—At the recent Conference on Water-Supply, held by the Society of Arts in connection with the London Health Exhibition, Mr. W. G. Topley read a paper showing how the location of the early settlements in England was determined by facility of access to water. The influence of this condition in attracting settlement to the shores of rivers, lakes, etc., is well known, but Mr. Topley showed also that the law operated with force in the case of the less imposing distribution of springs, and how long lines of early villages could be found situated along lines of territory where well-digging is practicable. Springs occur near where a pervious bed overlies or underlies an impervious bed, or where a valley reaches down to the level at which the rock is saturated with water. A soil which allows water to sink into it is a dry soil, and is, therefore, suited for habitation and for agriculture. Hence the main conditions which favor the settlement of a district are found in the same soil, or along the outcrop of the same bed. We thus see that geological structure controls the distribution of population, not only in such great features of the earth's surface as mountain-chains, plains, and valleys, but also in minor divisions of the district. The outcrop of a narrow band of porous rock beneath wide beds of clay is strongly marked by the occurrence of a long line of villages, each of which obtains its water from shallow wells or springs. When rocks rise from beneath a covering of clay, there are often springs at the junction. While the early settlements in England were nearly always controlled by these circumstances, relating to the distribution of springs, the later development of special towns and districts has depended upon a variety of conditions, many of which have become very complicated.
Construction of Stretchers and Ambulances.—Dr. Robert Lawson has given some valuable hints on the construction of stretchers and ambulances for the removal of the sick and wounded. It is most desirable in them to avoid or mitigate as far as possible inequalities and roughness in motion. Field-stretchers are liable to swing with the swaying from side to side of the bodies of their bearers and to a regular series of jolts. With each step he takes, the porter bends his body to the side on which a foot is touching the ground to maintain his equilibrium, and his burden follows him. The swinging may be diminished by causing the bearers to walk out of step, so that the sway of one to the right may be neutralized by the sway of another to the left. The jolts are consequent upon the shortening of the height of the bearer as his body bends over when the foot is set forward to make the next step. They are mitigated by ​shortening the length of the pace; a difference in height of three and a half inches, with a pace of thirty inches, may be reduced to about an inch and a half if the pace is shortened to twenty inches. If the stretcher-poles are round and too slender, the jolt is aggravated by their bending, sometimes by as much as two inches. A stretcher with square-cut poles, three square inches in section, weighed twenty pounds, and was found remarkably free from vertical oscillation, and easier to carry than one with lighter poles. The sacking of the stretcher should be six feet long. Legs should be attached to the frame, so that the couch shall be lifted above the ground when at rest. Ambulances should be made to receive the stretcher, and not compel a transfer. With a truck of five feet two inches, they may be contrived so as to admit two field-stretchers one foot eleven inches wide, and leave space for a partition an inch thick, to prevent the occupants from rolling. The motion of ambulances, at least in injurious directions, should be reduced as much as possible. Springs inside of the wagon, in addition to the ordinary springs, for the stretchers to rest upon, have been tried, but they have been found to produce discords in motion through the inequality in the rhythm of their vibrations, causing pain and injury to the patient. The wounded man is "most advantageously situated when he is subjected to the motion of the body of the wagon alone, at a point as near the floor as can be managed, and the ease of this motion can only be adequately provided for by careful adaptation of the springs to the weight they have to carry."
The Electric light and Health.—"The Bearing of Electric Lighting on Health" was the subject of an essay by Mr. R. E. Crompton and a conference at the recent Health Exhibition. Mr. Crompton held that the conditions of health were not so good in any kind of artificial light as in daylight. Even the electric light, diffused, is deficient in intensity and inferior to daylight. All artificial lights except the electric contaminate the air. At the twelve-candle standard, coal-gas vitiates 348, paraffine-oil 484, composite candles about 650, and tallow-candles 933 cubic feet of air per hour, but the electric light none. The amount of heat produced in the same time by the same lights is represented respectively by the numbers 279, 362, 383, 505, and 14. The criticism of the glare of the electric light is not just; we are not supposed to look at it. The real test is the intensity of the diffused light. The steadiness of the incandescent electric light gives it a great advantage over all others, and the arc-lights are also being made more steady. The eye-sight of the men in the British General Post-Office has been greatly improved since the electric lights were introduced. Other advantages of the electric light are the greater pleasure it gives, its greater convenience, and its absolute safety.
How State Monopoly of Railroads works.—An interesting view of the operation of the state monopoly of railroads in India was given a short time ago by Mr. J. M. Maclean before the British Society of Arts. Of 12,655 miles of railroad which were open in India on the 31st of March, 1883, 5,037 miles had been built by the Government, and 7,618 miles by companies working with the assistance or under the guarantee of the Government. Thus, the whole railway system of the country is in a very large measure controlled by the state. In the case of the guaranteed lines, the Government has contracted to pay the shareholders an annual interest of five per cent, paying two and a half per cent every six months. This arrangement is so carried out in practice as to work very unevenly as between the Government and the shareholders. If the net earnings of any line fall below the stipulated rate in a particular half-year, the Government has to make good the deficit, while, if the earnings are in excess, the surplus is divided between the Government and the shareholders. Now, in Western India, the profits of the railroads all come in one half of the year; and while in this half the roads may earn a surplus of profits amounting to hundreds of thousands of pounds, of which the Government gets a half, in the other half year the earnings may not be enough to pay the guaranteed interest, and then the Government has to bear the whole burden of the loss. During 1882-'83, the Government ​actually lost £231,380 on the guaranteed lines, while the shareholders pocketed a handsome profit in interest and surplus; and the state was saved from absolute loss only by the excessive profits it made out of a single one of its own lines. The system thus leads to the habit of regarding all the railways as one great property, and of seeking to make up for the losses that may be incurred on one set of lines by the more than legitimate profits which there may be opportunity to make on another set. The Government has thus become accustomed to the idea of maintaining its military and administrative lines at the expense of the commercial ones. The latter lines need enlargement to accommodate their increasing business, and would amply pay for it, but the state needs the money they furnish it, and which ought to be applied in that way, for the maintenance of its unproductive lines, and has adopted a penurious policy toward its productive ones. Whenever a complaint is made, or a proposition having in view a more liberal policy is agitated, a half-dozen boards and sets of officers in India and England "straightway begin to play an elaborate and interminable game of battle door and shuttlecock with the public interests. Any suggestion that is offered is minuted upon, referred, transferred, and generally knocked about, till the authors of it are ready to abandon it in despair." When called upon to interfere, the Government "is always, perhaps unconsciously, influenced by the thought that, if it sanctions increase of expenditure or reduction of rates, it may diminish its share of surplus profits. Hence the unwise parsimony which leaves main lines insufficiently supplied with rolling-stock to meet any sudden expansion of traffic." Our civil war was over before the Peninsular Railway was supplied with engines and cars enough to take away the cotton which choked all of its stations. The stations are glutted with wheat awaiting transportation to such an extent that the peasant dreads a good crop for fear that it will add to the quantity he must lose, because it takes on the average about five years to get the facilities that are needed on the instant. The Government hesitates when it should act, because it grudges an expenditure of capital, which, while it is comparatively insignificant and sure to bring ultimately a large return, means for the present a temporary reduction of profits on a lot of railroads, the most of which are losing ones.
Influence of Occupation on Physical Deyelopment.—The data obtained by the Anthropometric Committee of the British Association reveal some curious facts respecting the influence of occupation upon physical development. As a rule, the inhabitants of the country are taller and heavier than those of the large towns; but London is an exception, and seems to exert an attraction that draws in the more vigorous part of the country population. The metropolitan police, as a rule, are nearly as tall as the laborers of Galloway—the tallest of Britons—and twelve pounds heavier. The members of the Fire Brigade, who need not be so solid, but are expected to be active, are two and a half inches shorter and twenty-five pounds lighter than the policemen. Athletes average five feet eight and one third inches in height, and only about one hundred and forty-three pounds in weight; from which it is inferred that the majority of the population carry from ten to twenty pounds weight which they would not carry if they were in the highest physical condition. The Fellows of the Royal Society—a class of prominent intellectual gifts—are among the tallest of the race, averaging five feet nine inches and three quarters. The criminal class are forty-five pounds lighter than the police and four inches and a half shorter; and they are eighteen pounds lighter and two inches shorter than the average of the population. Lunatics are about as short as the criminals, but heavier. In men of the same occupation belonging to different races, the influence of race appears to be predominant over that of occupation.
Climbing the Himalayas.—Mr. Graham, an Englishman, with the help of two Swiss mountain-guides, has recently made an attempt to ascend some of the lofty peaks of the Himalayas. Starting from Nynee Tal, he found his first difficulty, and not an insignificant one, to be to get to the mountains. They stand far back, and are ​approachable only through valleys occupied by large streams. The first attack was made upon Dunnagiri, which is 23,184 feet high. In order to reach it they had to climb over two peaks 17,000 and 18,000 feet high, and then, after a five days' march, they camped on a glacier at the height of 18,400 feet. On the sixth day they reached a height of 22,500 feet, when, a snow-storm coming on, they were compelled to retreat, after they had come in sight of their goal. Mr. Graham observes that the peaks of the Himalayas, as a rule, are considerably steeper than those of the Alps; and he is convinced that breathing is no more difficult at the height he reached than at 10,000 feet lower down. The party also ascended the Kang La, 20,300 or 20,800 feet high, and a new mountain, 23,326 feet high, which was called Mount Monal, from the number of birds of that name seen upon its slopes.
Volcanic and Cosmic Dusts in Submarine Deposits.—Messrs. John Murray and A. Renard have taken advantage of the phenomena attending the eruption of Krakatoa last year for the extension of their studies in the accumulation of volcanic débris and cosmic dust in deep-sea deposits. Mr. Murray had already shown, before the Royal Society of Edinburgh, in 1876, that volcanic materials play the most important part in the formation of these deposits, and how they may have been furnished by the decomposition of pumice and the settling of incoherent volcanic ejections. Rounded fragments of pumice are collected on the surface of the sea in regions far from coasts, and at certain points on the bottom of the ocean the greater part of the deposit is composed of vitreous splinters derived from the trituration of such stones. The eruption of Krakatoa in a few hours filled the Bay of Lampong with about 150,000,000 cubic metres of ejected matter. Floating fragments from this source were collected on the surface of the water with their angles rounded off, and showing, as the only asperities upon their surface, crystals and fragments of crystals projecting beyond the mass of vitreous matter. The crystalline fragments and volcanic minerals can not be identified with certainty when reduced to their finest state, as in the deep-sea deposits; for in that condition they lose all their characteristics of form and optical properties. The case is different with the vitreous particles derived from the pumice, or included in the volcanic ash, whose characters remain constant to the extreme limits of pulverization. The results of the study of the micro-structure of the vitreous particles from Krakatoa, which are described in full by the authors, can be applied with most perfect exactitude to the volcanic dusts, which have been determined as such, in the deep-sea deposits. The latter have, however, only partly been derived from the pulverized ejections of a volcano, but more from the trituration of floating pumice; but it is hardly possible to trace the differences between the two. The minerals that can be determined in the ashes of Krakatoa are the same as are almost always found in the deposits along with the splinters of glass. It is not to be expected that the volcanic dusts found in all the deep-sea deposits shall be uniformly identical. In the first place, they may originate from magmas of varying characters, according as they come from volcanoes in different parts of the world. The matter also goes through a sifting process as it is carried through the air and in settling in the water. The vitreous particles, being lighter, are carried farthest from the volcanic center, and are longest in reaching the bottom. The fact has been illustrated in the case of Krakatoa that, in proportion as the ashes are collected at a greater distance from the volcano, they are less rich in minerals, and the quantity of vitreous matter predominates; a submarine tufa-deposit in the center of the South Pacific, in which the particles are graduated from the bottom up, illustrates the difference in the facility of settling. The evidence that has been adduced in favor of the hypothesis of a circulation in the atmosphere and a settling upon the earth of cosmic dusts is doubted by some, who have suggested various possibilities of an earthly origin for the particles described as cosmic. According to our authors, however, many of the doubts are at once removed by a statement of the circumstances under which cosmic spherules are formed in deep-sea deposits, and when the association of the metallic spherules with the most characteristic bodies of undoubted meteorites is shown. Cosmic particles are found in most ​abundance in deep-sea deposits at distances from land that preclude the supposition of their having originated in inhabited countries, and their form and character are essentially different from those of bodies collected near manufacturing centers, with which the attempt has been made to associate them. After describing some of these spherules, with graphic illustrations of their structure and composition, the authors express the belief that they have presented enough evidence to show that in their essential characters the spherules are related to the chondres of meteorites, and are formed in the same manner.
Manganese in Plants.—M. E. Maumené has found manganese in wines and in a considerable number of vegetable and animal products in which it had hardly been supposed to be present; and now announces, as the result of his latest investigations, that he has detected it in a great many plants. Wheat contains not less than from 115000 to 15000 metallic manganese, and rye, barley, rice, and buckwheat have also yielded considerable quantities of it. A little of it may be found in the potato, and more in the beet, the carrot, beans, peas, asparagus (principally in the green part), sorrel, wild chicory, lettuce, parsley, and in many fruits. It occurs in large proportions in cacao and the coffees, and in tea there are five grains of the metal to one kilogramme of the leaves. Tobacco is quite rich in it, as are also a variety of other plants, including some forage and some medicinal plants. The human system refuses to absorb it, and whatever of it may be introduced with the vegetable food in which it is present is eliminated with the fecal matter.
Gutta-Percha.—The earliest known mention of gutta-percha is by John Tradescant, who, in the catalogue of his "Rarities," preserved at South Lambeth (1656), mentions "plyable mazer wood," which, "being warmed in water, will work to any form." The earliest introduction of the gum to the commercial world is due to Dr. William Montgomerie, of the East India Company's service, who experimented upon it at Singapore, in 1822, and recommended it to the Medical Board of Calcutta in 1842 as a substance useful in the making of surgical splints. The name gutta is a Malay word, signifying gum, or juice. The gum is derived from the middle layer of the bark of a number of trees of the order Sapotaceæ to which order also belong the sapodilla-plum and the vegetable-butter trees. The principal source is the Dichopsis gutta, a plant which was described by Sir W. J. Hooker, in 1847, as Isonandra gutia. Dr. De Voiese, of the Dutch Government service, names eighteen species that yield the gum. The Dichopsis gutta is found in the Malay Peninsula, Sumatra, Borneo, and throughout the Malayan Archipelago generally. It grows to a height of from sixty to eighty feet, with a diameter of from two to five feet. The leaves are inversely egg-shaped (oblong in one variety) and entire, pale-green on the upper side, and covered beneath with a reddish, shining down. The flowers are arranged in clusters of three or four in the axils of the leaves. The fruit is a small oval berry. The gutta, as it flows from the tree, is of a grayish color, at times somewhat roseate in hue. When cast or rolled it assumes a fibrous structure, and acquires a tenacity in a determinate direction. At a temperature of from 32° to 77° Fahr., it has as much tenacity as thick leather, but is not at all elastic, and is less flexible than leather. In water, toward 120° Fahr., it softens and becomes doughy, although still tough; at from 145° to 150° Fahr. it becomes soft and pliant, assuming the elasticity of caoutchouc, but becomes again hard and rigid on cooling. It is highly inflammable, burning with a bright flame, and has marked electric properties.
Courtesy and Sagacity of the Duck.—A correspondent of the London "Spectator" extols the courtesy and sagacity of the duck. In illustration of the former trait, he tells of a "solitary, little, old bantam hen" he had among some fifty or sixty head of ducks and fowls, which became blind, or nearly so, and had to "sulk" in the dark to escape the persecutions of her mates. "Here," he says, "she might, perhaps, have starved, but for the constant and sympathetic attentions of a duck. Twice daily, every day so long as the poor bantam lived, some three weeks, this good Samaritan, in ​the form of a duck, was observed to fill her capacious beak with from twenty to thirty grains of barley, with which she proceeded to the fowl-house, and there deposited her store immediately in front of the bantam." Another anecdote is given in evidence of the sagacity of the duck. "I had five Aylesbury ducks, with a number of fowls. The lord of the yard, a most despotic chanticleer, would never suffer the ducks to feed with his family and friends when, at the regular meal-times, the grain was scattered for their common use. Ferociously, and without pity, he drove them from the ground. This had been going on for many weeks; and one day, at the twelve-o'clock repast, the act of expulsion was performed as usual. I was present, and saw the discomfited ducks retire to a corner of the yard. There they evidently held a conference. Having been so engaged some five minutes, they proceeded with deliberate and resolute air, in single file, as is their wont, toward their oppressor. Having reached the tyrant, they surrounded him, each duck turning his posterior toward the enemy, and with concerted action fairly hustled him clean out of the yard. To see the surprise of the cock, as he jumped from side to side to avoid the pressure of the attacking party, was ludicrous in the extreme. The victory was complete; from that hour the ducks were never again molested."
Attractions and Repulsions of Dust.—Mr. John Aitkin has recently performed some experiments illustrating the formation of clear spaces in dusty air. His apparatus consisted of a dust-box blackened inside, having a glazed front, and provided with a window on one side. Condensed light was admitted through the window from a dark-lantern. Dusts were made by chemical processes or from calcined magnesia, lime, or charcoal, and were stirred up by means of a jet of air. A round tube was introduced into the box and the dust stirred up, when it was observed that the dust came in close contact with the top and sides of the tube, but that below it a space was clear. This disposition of the dust was found to be an effect of gravitation, under which the falling particles did not reach the space immediately under the tube. When a thin plate was inserted vertically in place of the tube, no clear space was formed. No increased effect was observed on lowering the temperature from the normal; but, if a little heat instead of cold was applied to the round tube, the dark space rose and encircled the tube, and the two currents of clear air united over the tube to form the dark plane in the upward current. Heat was furthermore found to exert a real repelling effect on the dust. On heating the vertical metallic plate, the dark plane was formed in the ascending current in front of the plate, beginning with the slightest increase, and growing thicker with the rise, of temperature. With very high temperatures, produced by heating platinum wire in a battery, every kind of dust was found to have a different-sized dark plane; and, as the particles could be seen streaming into the dark space under the wires, it was obvious that these large dark planes were not caused by repulsion, but by the evaporation or disintegration of the particles. The effect of electrification of the hot surface was found to be opposite to that of heat, and dust was attracted to the surface or repelled from it, according as electricity or heat was applied with more force. It was also found that after the dust-particles were electrified they tended to deposit themselves on any surface near them, and electricity proved to be capable of depositing the very fine dust of the atmosphere. The air in a flask was purified much more quickly by means of the electric discharge than it could have been by means of an air-pump and cotton-wool filter. It was shown that a hot and wet surface repels dust more than twice as strongly as a hot and dry one. From this it was concluded that the heat and moisture in our lungs exert a protecting influence on the surface of the bronchial tubes, and tend to keep the dust in the air from contact with their surfaces. It was also observed that dust was attracted to cold surfaces and attached itself to them.
Chinese Plants in America.—Dr. D. J. MacGowan has published some notes on Chinese plants which it may be profitable to acclimatize in the United States. Among the plants he has recommended are several bamboos, the coir-palm, banian, ​planoconvex turnip, mat-grass, glutinous and red rice, and bitter orange. The trees used for the preparation of varnish form another group. Ningpo varnish is a compound article, the product of two trees; one a kind of rhus, or sumach, which has a wide range of growth, and the nut-oil tree, whence the nut-oil or "wood-oil" of commerce is derived, of which there are two varieties, the hill and the green variety. The varnish is made by combining the juice of the rhus and the nut-oil extract. An important varnish is also made from a wild persimmon, and a similar one is obtained from what appears to be an alga. The yang-mei or tree-strawberry, produces a famous fruit resembling the mulberry, which, it is said, is given a terebinthine flavor by a curious process of grafting on the fir. Lichi (Nephalin lichi, Nsungau) is a delicious tropical fruit, of which there are between thirty and forty kinds, and is found as high up as the latitude of 30° in Szechuen. Dr. MacGowan also suggests the expediency of experimenting with Chinese water-plants. Among them are the water-caltrap, which bears a valuable fruit; the tuberous water-chestnut (Ellocharis tuherosus); the chico pai, with celery-like shoots; the chin tsai, or water-celery, which is cultivated in floating gardens built on bamboo rafts; the t'ish-shu, or iron-tree, "the most beautiful of the Cicadaceæ," which is revived, when it grows old, by driving iron nails into its trunk; and the tiao-lau, a hanging epidendron, which flowers only when taken from the ground and suspended from a ceiling.