Popular Science Monthly/Volume 1/July 1872/Miscellany

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Length of Guns.—General Morin, in a discourse delivered before the Paris Academy of Science, noted this curious circumstance, that, though different kinds of powder may give equal speed to a projectile, they may differ very much from one another in the pressure they exert upon the walls of the cannon. He further remarked that all the grades of powder that have been tested undergo entire combustion, and consequently produce all their effect in pieces whose length is 12 times their calibre. But yet the greater part of the field-pieces in use have a length equal to 30 times their calibre. They might be cut down, therefore, without prejudice to their efficiency, and thus their portability would be increased.

Late Researches on the Gastric Juice.—The gastric juice of the human stomach has lately been made a subject of special study by Dr. Leube, of Erlangen, who gives the fruits of his work in an elaborate paper read at the recent Rostock Congress. He obtained the juice for his experiments by means of a tube introduced into the gullet. The gastric juice obtained from the stomach, empty and cleansed by an injection of water, is slightly acid, doubtless owing to the irritation caused by the injection and the contact of the instrument. Its digestive power is weak. In the course of his experiments with this fluid, Leube found that cheese is digested more rapidly than the albumen of a boiled egg, and the latter more rapidly than the albumen of a raw egg.

Experiments made with quassia demonstrate that this substance does not exert any special exciting action upon the secretion of the gastric juice. It excites it only as any other body might, which is brought into direct contact with the mucous coat of the stomach. The action of bitters upon the gastric secretion is, beyond doubt, a reflex action, having its point of departure in the mucous membrane of the mouth.

In the course of the discussion which ensued, Dr. Hoppe Seyler observed that in dogs, when fevered, the gastric juice suffers a diminution of its acid, but not of its pepsin. The white of the egg, in order to be dissolved, must first be transformed into syntonine, which process requires a gastric juice of great acidity. This fact accounts for the difficulty with which albumen is retained upon a disordered stomach. As concerns the digestibility of cheese, that substance is composed of different ingredients, and notably it contains one phosphoric substance, utterly indigestible, nuclein.

Sanitary Reform in India.—Lord Mark Kerr sends a communication to the (East) Indian Medical Gazette, in which he relates how he came to discover the cause and means of prevention of what is called the Delhi Boil, formerly the scourge of the denizens of Delhi, native and foreign. From a comparison of the situation and surroundings of Delhi with those of other Oriental cities similarly noted for the prevalence of boils and sores, he was led to conclude that the cause of the disorder was to be found in the existence, within the walls of the town, of a barren strip of land, two miles in length, by 500 yards in breadth, covered with foul weeds and ruined buildings, with the wells and water-courses choked up. He proposed to clear the water-courses and plant trees and grass. This was done in 1864, and now the Delhi Boil has entirely disappeared from the city. Lord Mark Kerr desires to have his experience tested throughout India, for he believes that pure irrigation and draining, with judicious planting and gardening, would greatly tend, not only to remove sores and such-like evils, but to prevent the approach of more serious and even fatal scourges.

A New Anaesthetic.The Medico-Chirurgical Circular (German) calls attention to a new anesthetic, which has received the name Aethelid Chlorid. Dr. Langenbeck has employed it in six operations, and found that it produced anæsthesia more rapidly than chloroform. He states that its use is unattended with any of those unpleasant effects which commonly attend the exhibition of chloroform. Also a new method of producing anæsthesia with morphine has been discovered. In this method hypodermic injections of the chlorhydrate of morphine are given, followed up with light inhalations of chloroform. Three cases were cited where this method had been employed satisfactorily. The anæsthesia, in this case, is not attended by sleep, and it leaves the action of the mind, the senses, and the voluntary muscles intact.

Liebig's Extract of Meat.—Liebig's process of obtaining meat extract is found to yield only 14 per cent, of the dry, solid material of the meat. The remaining 86 parts are the really nutritive constituents of meat, and the 14 contained in the Liebig extract are merely stimulative, not nutritive. This is, with ingenuous candor, admitted by Liebig himself. An English pharmaceutist, Mr. Darby, claims to have invented a process of obtaining, in concentrated, soluble form, all the constituents of the meat. His process, which has been patented, is this: Lean meat, finely sliced, is digested with pepsin, in water previously acidulated with hydrochloric acid, at a temperature of from 96 to 100 Fahr., until the whole of the fibrine of the meat has disappeared.

The liquor is then filtered, separating small portions of fat, cartilage, or other insoluble matters, and neutralized by means of carbonate of soda; and finally carefully evaporated to the consistence required, namely, that of a soft extract.

The resulting extract represents, in all its constituents, the lean meat employed, but with the fibrine, albumen, and gelatine, changed into their respective peptones, or soluble forms. This change is effected solely by the pepsin and hydrochloric acid, or artificial gastric juice, without the evolution or absorption of any secondary products.

But this process, whatever care be taken, leaves the fluid meat with a strong bitter taste, which always attaches to meat digested with pepsin. "In order to remove this bitter taste, I have made," says the patentee, "very many experimental researches, and at length have discovered that the purpose is completely and, satisfactorily effected by the addition, in a certain part of the process, of a small portion of fresh pancreas."

The fluid meat so prepared is entirely free from any bitter flavor. One ounce is the equivalent of 20 ounces of meat.

Do Planets vary in Color?—In a note to the Royal Astronomical Society, Lieutenant-Colonel Strange, F. R. S., suggests that the changes of color which have been observed at distant intervals in some of the planets, may after all be an affair of the optical instruments through which the light is made to pass, rather than any real alteration in the aspect of the planet itself. That optical instruments do sometimes give the impression of a color different from that belonging to the object from which the light proceeds, appears from the following, which we quote from Colonel Strange's communication:

"I was, within the last few days, at a theatre with two young ladies. They drew my attention to 'the lady opposite in pink.' Turning my glass to her, I replied, 'You mean the lady in yellow.' 'No,' replied both, 'her dress is pink.' Having ascertained that we all spoke of the same person, I begged my companions to use their glasses. On doing so they both at once admitted the color to be yellow, as I had said. But they assured me that to their naked eye it was pink as before. One of the young ladies, my own daughter, is considered to have a remarkably fine eye for color, with the faculty of matching and remembering tints very strongly developed. The other, also a near relative, is likewise an excellent judge of color, and a born artist. The dress about which the above doubt arose was not all colored. It was white, with a great deal of the doubtfully-colored trimming, and the tint (whatever it really may have been) was very pale. There was strong light upon it, and the distance was that of the whole greatest diameter of a small theatre. Such are the facts, on which I do not propose to theorize. But they certainly point at least to one practical consideration namely, the influence of optical power on color impressions, and the necessity of great caution in pressing observations on the color of heavenly bodies into the service of speculations regarding cosmical changes."

Of the three elements—form, size, color—Colonel Strange believes that color is the least permanently fixed in the "sensorial memory;" so that, even if the light reached the eye of the observer unchanged, the comparison of a recent color-impression with one that was received a long time before must at best give but a doubtful result.

A New Writing-Machine.The Mechanics Magazine figures and describes a new form of writing-machine, the invention of the Rev. Mailing Hansen, superintendent of the Royal Deaf and Dumb Institution of Copenhagen. The machine is designed for rapid writing, and is also capable of being used by the blind. The work is done by means of a series of keys, moved by the fingers something in the same way as the keys of a concertina, each key leaving the impress of its proper letter or character on the paper below when it is struck by the finger. The keys are so disposed that the imprint of each type, when struck, is directed to, and received upon, a central spot, over which the blank paper is made to travel by means of suitable machinery.

Besides offering great facilities for copying purposes, the machine is said to rival stenography as a means for reporting speeches or taking down dictated composition. Rapid writing rarely exceeds four letters per second, while in ordinary speaking from nine to ten, and in rapid speech from fifteen to twenty, letters are uttered per second. This machine, with a little practice, enables the operator to take down an average of twelve letters per second, and an expert manipulator can considerably exceed this. The instrument is in use in London, and its performances are said to be very satisfactory.

Weather-Waste of Coal.The Engineer states that Dr. Varrentrapp has made the weather-waste of coal the subject of an investigation, and as a result asserts that the amount of loss suffered by coal from exposure to weather is considerable, far greater, indeed, than is generally known. The results of his analyses show in some cases a total loss in weight of a specimen, from this cause, amounting to 33.08 per cent., while its deterioration in quality, for purposes of fuel or gas-making, reached a still higher figure. This change consists in a slow combustion, in which the volatile constituents—which are most valuable combustible elements are gradually eliminated, while the relative proportions of carbon-ash and sulphur are comparatively augmented. It might be expected, now that the nature of this change is indicated, that anthracite (which has already gone through a very similar process in becoming what it is by the loss of its bituminous matter) should suffer least of all coals from this action, and the result of analysis shows this to be the case. The density and compactness of this variety, aside from its chemical character, protect it in no inconsiderable degree. The cannel coals rank next in their power to resist deterioration from this source, while the bituminous varieties are the most susceptible. The experiments of Dr. Yarrentrapp are of such direct and practical importance that all who are engaged in the mining, transportation, storage, or consumption of coal, can study them with profit. It appears from accurate tests of a number of samples before and after exposure, that all the valuable properties of the coal had deteriorated. The coking quality of the weathered coal diminishes with its gas-yielding quality, the author informing us that a sample of coal, yielding when freshly mined a firm, coherent coke, after eleven days' exposure yielded a coke of no coherence, and in all the samples tested the rule was absolute that the longer the coal had been exposed the greater was the inferiority in the quality of the coke it produced. The gas-yielding quality decreased in one instance 45 per cent., and the heating power 47 per cent.; while the same sample under cover lost in the same time but 24 per cent, for gas purposes, and 1 2 per cent, for fuel. These experiments go far to explain the almost universal inferiority of the Black or waste coals in heating power when prepared for burning, even though some combustible material like pitch or tar is used in their cementation. It indicates, too, the imperative necessity of keeping coals amply protected from the deteriorating action of the air and moisture, by keeping them constantly dry and under cover.

Anecdotes of Rats.—A gentleman, who has passed many years of his life at St. Helena, told me lately several stories about rats, so curious that I thought them worthy of record. He said that at one time the common brown rat was extremely common all over the island, in fact, a perfect pest; and, to avoid its attacks, his father had constructed a large store, rat-proof; i. e., a rat once in could not get out again. A number, however, came in with produce and goods from the ships, and bred there. Around this store were Venetian blinds to the windows, and one day one of his men, when it was raining, watched a rat sitting on the Venetian, and putting out his tail to collect on it the drippings of water at the edge; he then withdrew it and licked it. The servant told his master, who immediately understood that the rats could get no water inside the store, and therefore directed that a butter firkin should be cut down to four or five inches, and in the top a large circular wire rat-cage trap should be fixed. Several small planks were placed for the rats to get up to the entrance to the cage, which exactly fitted the firkin. No food would have induced the rats to enter the trap, but water did, and many were thus captured. When caught they were given to the dogs; but there was one rat which would not leave the trap for many days. He was well identified day by day, till, becoming incautious, he leaped down, and was immediately killed. There is one peculiarity with these rats, viz., their very often building or making their nests in the trees. I have in India several times found rats'—nests in trees; but then they have always been stolen nests, such as deserted abodes of the squirrel or sparrow; but here my friend, who is no naturalist, tells me that they construct them principally of fir spines, on the ends of the boughs, some twelve or fifteen feet from the ground, in the common fir-trees. The spots selected are just where the overlapping bough nearly meets the lower one. He said that all know the rats'-nests, and that he had seen them fired at, when many rats were killed, and fell out to the ground. He could tell me no more, and I think that, if original nests, as he held them to be, some grass must be woven in during their construction, as fir-spines have but little power of cohesion. The situation of these nests was worthy of notice, although there is scarcely a situation where a rat's-nest has not been found.—C. Horne, F. Z. S., in Science Gossip.

Spontaneous Explosions of Gun-cotton.—Fired in the open air, gun-cotton burns with great rapidity, but does not explode. It has accordingly been the practice to store the manufactured article in more or less open sheds, in boxes containing twenty-five or thirty pounds each. In this condition, however, several explosions have taken place; the most serious being one that occurred at Stowmarket, in England, something less than a year ago. In this case the ignition of the gun-cotton was shown to be due to the presence of a large quantity of sulphuric acid in the stored material; but why it should explode when ignited, instead of burning up in the ordinary way, was not so readily explained. To clear up this point, a set of experiments has lately been carried out, the results of which are given in a recent number of the Engineer.

The "service-boxes" in which the gun-cotton is kept are made of inch boards, and, when filled, the cover is tightly screwed on. Twenty-four such boxes were piled in a light wooden hut, similar in construction to the sheds in which gun-cotton is ordinarily stored, and twenty-four others were placed in a close-built brick magazine. Two boxes in each building were left partially open to facilitate ignition of the cotton. The wood hut was ignited by a bonfire of shavings, cotton, and petroleum. It smouldered for about seven and a half minutes, and then broke into the full characteristic gun-cotton flame, when in nine seconds more explosion took place. The cotton in the brick magazine was next ignited; smouldering followed for one minute, fierce gun-cotton flame for ten seconds, then an explosion. Experiments with the wood hut were afterward tried, with the cotton in light wooden boxes, and the lids partially open. It burnt in every experiment without explosion. The results are thus summed up: "Gun-cotton in service-boxes, packed in a close brick magazine, when ignited exploded; gun-cotton in service-boxes tightly screwed down, packed in a wooden hut, exploded; gun-cotton packed in light ½-in. boxes, with lids only partly screwed on and left partly loose, packed in a wood hut, burnt without explosion twice. The same experiment, differing only in the cotton being damped, caused no explosion." The inference therefore is, that confinement of the gases generated by burning, in tight, strong, wooden boxes, was the cause of the explosions, as, when not so confined, the burning went on as in the open air. "Apparently, the tendency of the experiments is to recommend, as the condition likely to be safest against explosion, that boxes should not be tightly closed or packed in high piles."

Culture of Wild-Plants.—A daughter of Dr. Lockwood, of Freehold, N. J., planted last year in the garden a root of the wild-violet, known to botanists as Viola sagittata. It had, during the first ten days of May of this year, borne over three hundred flowers, and was at that date a mass of cerulean bloom, with prospect of producing as many hundred more of flowers. The great advantage of this violet is, that its leaves do not grow so high in generous culture as do those of the species V. cuculata, or its variety V. palmata. Hence the luxuriant mass of flowers is always uppermost, and the rich blue is thus kept conspicuous. This same young lady, at the Monmouth County Fair last year, exhibited a case of living and growing wild-plants under the name "A Cryptogam Garden," which elicited great admiration. It was composed of rare indigenous ferns, all gathered in the wilds of the county. Among these was that graceful rarity, the climbing fern, Lygodium palmatum. There were mosses and lichens, and fungi of recherché forms and brilliant colors. The effect was very fine, and showed how rich are the resources at hand where there is a little taste to turn them to account.

Chameleonization in Frogs and Reptiles.—We published, in a previous number, a curious and interesting article by a German oculist, showing how the colors of paintings are affected by changes in the eye of the painter. M. Pouchet matches this discovery with the curious fact that the lower animals change their own colors through the action of the eye. In a recent work on change of color in Crustacea, this author shows that in fishes, especially the turbot, notable changes of color take place, due to the quantity of luminous rays which fall upon the eyes of these animals. The eye is the point of departure for a nervous shock which is transmitted to the skin, and which finally results in a change, more or less complete, of the color of the animal. This shock, starting from the eyes, is transmitted by nerves to the skin; so that, if certain of these nerves be severed, the animal will become striped with clearly-defined bands, the shock being intercepted by the severed nerves, and transmitted by the others. If the animal is deprived of sight, it ceases to change color, and preserves the same tint, whether it be placed on a black or on a white ground. In the course of his researches at Concarneau, M. Pouchet confirmed these results in the case of Crustacea.

The skin of the frog becomes clearer when the cutaneous nerves are severed. Prof. Goltz, of Halle, shows that primarily the action of the nerves affects the vessels, and that the change in the pigment-cells is a secondary result, and due to a modification of the circulation. In the active state, these cells are star-shaped, or branching; in repose, they are round. Having removed the spinal cord and brain, if then you sever the nerves leading out to one portion of the skin, that portion will become clearer, the pigment-cells then first assuming the condition of repose. Dr. Witlich thinks this change of color is owing to the decay of the color-bearing cellules, and says it would take place equally in shreds of skin separated from the body. Dr. Mendel, of Berlin, has observed one-sided pigmentation frequently in the insane.

Observations on the Hydrogen-Flame.—Besides the phenomena common to ordinary burning, such as luminosity, the disappearance of oxygen, and of the substance burned, the production of water and carbonic acid, or some other of the various oxides, there are also certain other phenomena that differ with different substances, and that, when known, often become an important means of distinguishing these substances. Thus, burning sodium gives a yellow flame; burning potassium, a flame of a purple color; burning arsenic, a strong odor of garlic; burning sulphur, suffocating fumes of sulphurous acid, and so on. Burning hydrogen also has its peculiar phenomena, which have lately been made the subject of further investigation by Mr. W. F. Barrett, who contributes an interesting account of his researches to a recent number of Nature.

To study these phenomena to the best advantage, three things, he says, are requisite: 1. That the gas be purified and stored in the ordinary way; 2. That it be led through red or black India-rubber tubing to a platinum, or, better, a steatite jet; 3. That it be burnt in a perfectly dark room, and amid calm and dustless air. In this way, the flame gives a faint, reddish-brown color, invisible in bright daylight. Issuing from a narrow jet in a dark room, a stream of luminosity more than six times the length of the flame is seen to stretch upward from the burning hydrogen. This weird appearance is probably caused by the swifter flow of the particles of gas in the centre of the tube. The central particles, as they shoot upward, are protected awhile by their neighbors; metaphorically, they are hindered from entering the fiery ordeal which dooms them finally to a watery grave.

Brought in contact with certain solid bodies, the flame gives rise to phosphorescent effects. Thus, allowing it to play for a moment on sand-paper, and then promptly extinguishing the gas, a vivid-green phosphorescence remains for some seconds. A similar appearance follows when the flame is directed upon white writing-paper, marble, chalk, granite, or gypsum.

A much more general effect than the one last mentioned is, the production of a magnificent blue image of the flame, that starts up on almost every substance with which the flame is brought into contact. When directed either vertically or sideways, say upon a white plate, or block of marble, there instantly appears a deep-blue and glowing impression of the exact size and shape of the hollow flame. The moment the gas is extinguished, or the flame removed to the slightest distance from the solid, the effect ceases. This appearance, and the blue tinge which is said to be peculiar to the hydrogen-flame, are really due, according to Mr. Barrett, to the presence of sulphur, and so delicate is the reaction with this substance, that, without the greatest care in purifying the gas, and cleansing the surfaces with which, when burning, it is brought in contact, sufficient sulphur will be present to perceptibly color the flame. The least trace of phosphorus is also made apparent by the hydrogen-flame, by the production of a vivid-green light. When made to play upon the surface of clean tin, or some alloy of tin, a fine scarlet color is almost instantly produced, though the appearance is less vivid than with either sulphur or phosphorus.

Many gases also impart color to the hydrogen-flame; hydrochloric-acid gas giving a reddish-brown flame; ammonia gas a yellow flame, etc. Carbonic-acid gas, even in the smallest proportions, gives the flame a pale lilac tinge, the color being most marked at the base of the flame.

Mr. Barrett suggests that the delicacy of these various reactions makes it possible to turn them to valuable practical account, in the detection of the substances named. When, for example, the air of a room has become vitiated by the accumulation of an undue amount of carbonic acid gas, the hydrogen-flame, by means of suitable apparatus, will readily make the condition known. This practical side of the subject is now engaging Mr. Barrett's attention.

Recent Cave Explorations.—Some highly-important discoveries have lately been made in a cave near Luchon, France, by M. Piette, of the Geological Society. The soil of the casern consists of several layers—the lowermost ones being characterized by the bones of the reindeer, and by dressed flints like those of the grotto of Laugerie-basse. These layers enclose, in addition to human bones, a large fauna, and particularly a considerable quantity of carved bones and stones. Nowhere else has so great an accumulation of prehistoric works of art been found. The figures often cannot be recognized; still on the bones are seen some designs of considerable finish. M. Piette mentions, among other carvings, some that represent flocks of wild-goats, and herds of reindeer, the head of a rhinoceros, a wolf, horses, a lion's head with mane, etc. These valuable remains are buried in a black soil, filled with ashes. Near the surface of this layer the fauna is the same as it is below, but the carvings are very different from those underneath, and show a very marked decadence. While the lower ones reproduce Nature exactly, with extreme care and a certain minuteness of observation, the upper ones are fantastical and not after Nature, as well as ruder than the others. All the human bones, especially the bones of the skull, are reduced to small fragments, and all have notches and incisions more or less deep. This, M. Piette takes as an evidence of cannibalism. The topmost layer is hard and compact.

Relation of Death-rate to Temperature.—In a little work on the climate of Uckfield (England), Mr. J. Leeson Prince has the following concerning the influence of temperature on the death-rate:

"The mean annual temperature varies 5°.3, viz.: from 51°.93 in 1857, to 46°.62 in 1845, and although at first sight this difference may not appear considerable, yet it is sufficient to exert an enormous influence upon the general character of the seasons, the produce of the soil, and the health of the population. The registrar-general's interesting returns have fully established the important fact that there is a very intimate connection between temperature and mortality. Whenever the mean temperature falls to 45° or thereabouts, the number of deaths from diseases of the respiratory organs increases; and, should it fall below 40°, the death-rate from such diseases is still higher. When a period of intense cold prevails, so that the temperature scarcely rises above the freezing-point for two or three weeks, the number of deaths will be found to exceed what takes place during an epidemic of cholera or scarlet fever. But, when the mean temperature rises to 55°, there will be an increase in the number of deaths from diseases of the abdominal viscera, and this number will fluctuate as the temperature fluctuates between 55° and 65°. Hence we are informed that the mortality from all causes is least when the temperature is about 50°, which is very little above our mean annual temperature."

The Late Eruption.—A correspondent of the London Athenaeum, writing, May 2nd, from Naples, graphically describes the late eruption. He says: A tempest of fine ashes poured down upon us, covering the streets and houses, filling our lungs, and almost blinding us. We all, from necessity, carried umbrellas, a slight protection, however, except to break the brunt of the driving shower as we met it. I have seen cabmen with handkerchiefs hanging in front of their caps, and some men with fine handkerchiefs tied over their faces. Last Friday and Saturday it was, as it were, one continuous roll of artillery, so loud that it could be heard full 20 miles distant; but after the sandstorm set in, if not so sharp and violent, it was, I think, more appalling. Vesuvius roared night and day; it rendered sleep impossible; its reverberations shook our windows and our houses, and great has been the exodus from Naples of the foreigners who came to admire, and now have fled in fright.

It is impossible adequately to describe the beauty and grandeur of the spectacle. In its totality it met the eye—one could watch the swelling growth of the eruption, its every movement, and mark all the exquisite proportions of that wonderful creation, whereas close under the mountain there was a terrific confusion of forms. On the afternoon of Wednesday week there was a grand display, which would have been sufficient for one season, and foreigners might have dispersed to their homes, delighted that they had at last witnessed a brilliant eruption of Vesuvius. On the Thursday it was less active, but in the night there was a cannonade, a loud continuous roar, which never ceased a moment for 48 hours. At the distance of 20 miles it shook the windows and murdered sleep; and one thought only of the havoc which was then being committed on fair lands and populous villages. Like a gigantic cauliflower rose up that vast mass of fire and smoke. Do not smile at the homeliness of the comparison, for it is the only one which really represents its form. Its thousand involutions, round and swelling, are well imaged by the sections of the plant, and as they emerged from the volcano they grew in height and magnitude, and intermingled and rolled one over the other until they ascended to the zenith, and then toppled over, section after section, and fell by their own weight. I could see the showers of dust on either side, and in the midst, burning stones like stars; yet the height of this marvellous form was never lessened, for underneath curled up continually fresh supplies, while the thunder, which rolled fearfully, gave a never-failing impulse to their ascent. A slight wind from the northwest detached portions of the column on one side, and sent them down the coast for miles, in one long cloud; as the wind varied, it was swept inland, or across the sea. And then the colors, how exquisite they were! There were artists with me who positively raved. We had the pure white of the homely plant on the summit, while each section was divided from the other by a shade of black. As the setting sun cast its light upon it, we had all the prismatic colors of the rainbow, and then night fell, and the entire mountain, the heavens above and the sea beneath, were on fire.

Eastern Thibet.—According to Dr. Campbell, from whose papers on Eastern Thibet Nature gives an interesting abstract, the dong or wild-yak of that country is the fiercest of all known ruminants, rarely allowing a man to escape if it can come lip with him. Like the American buffalo, this animal is generally hunted on horseback. The domesticated yak and the sheep are used for the transportation of salt, which is brought from all but inaccessible districts, having an elevation of some 22,000 feet, and where it is so cold that salt can only be obtained from April to November. The sheep carries a load varying in weight from eight to twenty-four pounds, according to the character of the route; the salt is thus conveyed to places accessible by yaks, which are capable of bearing a load of 160 pounds.

There are no leeches or mosquitoes in Thibet, nor are maggots or fleas ever seen there; and in Dingcham, or Thibet proper, there are no bees or wasps.

Of the mineral productions of the country, a form of carbonate of soda called pen, borax, saltpetre, common salt, gold, and arsenic, are spoken of by Dr. Campbell. There are no mines of iron, silver, copper, quicksilver, lead, or coal; the latter substance is, however, imported from China.

The turquoise, real or artificial, is universally worn in rings, necklaces, etc., and large amber-like beads are a favorite ornament, but it is uncertain whether they are natural products of Thibet. The latter are apparently composed of turpentine, mixed with some hardening material. Numerous imitations of turquoise are imported from China; and real but not valuable stones are sent, via Cashmere (but from what locality is not stated). The only test of a real stone that is resorted to by the Thibetans is to make a fowl swallow it; if real, it will pass through unchanged.

Dr. Campbell gives some very interesting information regarding the food of the Thibetans. During the summer months they use very little fresh meat. They do not like it boiled, and are not partial to it raw, unless it has been dried. In November there is a great slaughter, and a wealthy man, who has perhaps 7,000 sheep, will kill 200 at this time for his year's consumption. The animal after being killed is skinned and gutted, and then placed on its feet in a free current of air. In a couple of days it becomes quite hard, and is then ready for eating. It is kept in this way for more than a year without spoiling, even during the rainy periods. When long exposed to the wind of Thibet it becomes so dry that it may be rolled into powder between the hands. In this state it is mixed with water and drunk, and used in various other ways. The Thibetans eat animal food in endless forms, and a large portion of the people live on nothing else. The livers of sheep and other animals are similarly dried or frozen, and are much prized, but to strangers they are very distasteful for their bitterness and hardness. The fat is dried, packed in the stomachs, and then sent to market or kept for home use.

With regard to edible vegetables, it is stated that wheat, barley, and buckwheat, sown in April or May, and irrigated, are reaped in September, barley in Thibet taking the place of potatoes in Ireland, four-fifths of the population living on it. Besides these, the other crops are composed of peas, turnips, and a little mustard. The grain is ground in water-mills. The bread is all unleavened, and cooked on heated stoves or gridirons. The sweet, pure farinaceous taste of the fine flour equals the best American produce. The staple food of the country is champa, called suttoo in India; it is finely-ground flour of toasted barley. It is much eaten without further cooking; mixed up with hot tea it is called paak, and when prepared with tepid water it is known as seu. If any of our readers wish to enter upon "pastures new" in the breakfast department, they may try tookpa, which, to be properly appreciated, should be taken at daybreak before any matutinal ablutions. It is a sort of broth made with mutton, champa, dry curds, butter, salt, and turnips.

Goats are also reared in considerable flocks, but for their milk rather than their flesh. The milk of yaks, cows, sheep, and goats, is used alike for making dried curds and the various preparations of milk used by these people. Mares' milk is not used in Eastern Thibet.

Among the afflictions of the Thibetans Dr. Campbell mentions groomtook, or the laughing disease, which consists of violent fits of laughter, with excruciating pain in the throat. It equally attacks men and women, and often proves fatal in a few days.

Flying Reptiles of the Chalk Formations in Kansas.—Prof. E. D. Cope, whose industry and genius have done great service in making us familiar with the strange animal forms of the reptilian age in this country, describes two species of flying saurians found by himself in the chalk-deposits of Kansas. One of these had probably been discovered previously by Prof. Marsh, of New Haven, and described under a name different from that given by Prof. Cope.

These belong to a genus which comprises the largest of the pterodactyles or flying saurians, a class of reptiles long since found in Europe, but not until recently discovered in this country.

One of the Kansas species measures 18 feet between the tips of its wings, while the expanded wings of the other would cover an expanse of 25 feet.

These animals had strong, claw-bearing digits, and a short tail, with slender heads, and teeth indicating carnivorous habits.

"We may imagine them," says Prof. Cope, "napping their leathery wings over the waves, and plunging, often seizing many an unsuspecting fish; or, soaring at a safe distance, viewing the sports and combats of the more powerful saurians of the sea. At nightfall they may have suspended themselves from cliffs by the claw-bearing fingers of their wing-limbs."

Origin of Cholera.—According to a recent paper by Mr. B. G. Jenkins, on the origin and distribution of cholera epidemics, of which Nature gives an interesting abstract, the ancients were not so far wrong, after all, in their belief that the heavenly bodies were intimately connected with the origin and course of disease. Instead of one "home" of the cholera in the delta of the Ganges, this writer holds that there are seven, all situated on or near the Tropic of Cancer. These are equally distant from each other, and, while that at the mouth of the Ganges is the most important, the others, which are to the east of China, to the north of Mecca, on the west coast of Africa, to the north of the West India Islands, to the west of Lower California, and among the Sandwich Islands, are well marked, and have all been the starting-point of "cholera-streams" 1,400 miles in breadth, which took either a northwesterly or southwesterly direction, or both. After pointing out the rise and progress of the disease within the limits of these several streams, the author mentions the curious cases of ships at sea being suddenly attacked by cholera; and again, the instances of ships sailing along the coast of India being struck by the disease when at the same place, explaining them on the supposition that the ships had been sailing within the limits of the cholera-streams; for, when they got outside the limits, the disease suddenly ceased. He called attention also to the fact that all the places recorded by Dr. Gavin Milroy as unaffected hitherto by cholera, lie outside these streams, or in their possible, but not actual, extension.

Leaving this part of the subject, he next discusses the origin of the disease, declaring that "cholera is intimately connected with auroral displays and with solar disturbances." Instancing the observed periodicity of the sun-spots, of the diurnal variation in the amount of declination of the magnetic needle, of the earth-currents, and of the aurora?, he traces a curious coincidence in the periodicity of cholera epidemics, expressing the belief that they have a period equal to a period and a half of sun-spots. He adds: "My own opinion, derived from an investigation of the subject, is that each planet, in coming to, and in going from, perihelion—more especially about the time of the equinoxes—produces a violent action upon the sun, and has a violent sympathetic action produced within itself—internally manifested by earthquakes, and externally by auroral displays and volcanic eruptions, such as that of Vesuvius at the present moment; in fact, just such an action as develops the tail of a comet when it is coming to, and going from, perihelion; and, when two or more planets happen to be coming to, or going from, perihelion at the same time, and are in, or nearly in, the same line with the sun—being, of course, nearly in the same plane—the combined violent action produces a maximum of sun-spots, and in connection with it a maximum of cholera on the earth. The number of deaths from cholera in any year for example, the deaths in Calcutta during the six years 1865-70—increased as the earth passed from perihelion, especially after March 21st, came to a minimum when it was in aphelion, and increased again when it passed to perihelion, and notably after equinoctial day; thus affording a fair test of my theory."

The Yellowstone National Park.—Interesting details of the Yellowstone National Park reservation are given by F. V. Hayden, United States Geologist, in his fifth annual report on the Geology of the Territories, just published.

By act of Congress, approved March 1, 1872, a tract of land in the Territories of Montana and Wyoming is set apart and reserved for a national park. It is situated between 44° and 45° of north latitude nearly the same as are the White Mountains and the Adirondacks is 65 by 55 miles in area, and comprises 3,575 square miles.

Every portion of this area is more than 6,000 feet above the level of the ocean, or nearly as high as the summit of Mount Washington. In it is a beautiful sheet of water, the Yellowstone Lake, 330 square miles in area, and 7,42*7 feet above the sea. Tremendous gorges, chasms, canons, waterfalls, and forest, make this whole tract surpassingly wild. It is walled on every side by mountain-ridges, from 10,000 to 12,000 feet high. On these elevated summits lie perpetual snows, which feed three of the largest rivers in North America.

The sources of the Yellowstone and Missouri, which empty into the Mississippi, and thence into the Gulf of Mexico—of the Snake River, which flows westward to the Columbia and the Pacific—of the Green River, which discharges its waters through the Colorado into the Gulf of California—are among these mountains.

This whole region was in recent time volcanic. The mountains are of volcanic origin. A vast number of hot springs, mud-volcanoes and geysers of a temperature from 100° to 195° Fahrenheit, indicate the close proximity of the unextinguished fires.

On account of its great elevation, frost forms every month in the year. In summer the thermometer falls to 26°, but the air is clear and invigorating. The reservation of this wild and magnificent tract, so abounding in the most wonderful phenomena of Nature, was a wise foresight, and a tribute to Science in the highest degree honorable to our government.

At a recent dinner of the London Academy of Art, Prof. Tyndall thus happily expressed himself touching the relations of art and science: "There is no reason why art and science should not dwell together in amity; for, though they are both suitors of the same mistress, Nature, they are so in a sense and fashion which preclude the thought of jealousy on either side. You love her for her beauty, we for her order and her truth; but I trust that neither of us is so narrow-hearted as to entirely exclude from himself the feelings which belong to the other. Indeed, each is necessary to the completion of the other. The dry light of the intellect, the warm glow of the emotions, the refined exaltation of the aesthetic faculty, are all part and parcel of human nature; and to be complete we must be capable of enjoying them all. Trust me that we, whose light on earth is for the most part that dry light to which I have referred, often seek, and sometimes have, 'glimpses that make us less forlorn' of those aspects of Nature which reveal themselves in all their fulness to the eyes of art. We need such glimpses as a compensation for much that the times have taken away from us. There are some of us workers in science who largely share the poet's yearning to 'hear old Triton blow his wreathed horn,' and who, nevertheless, in opposition to natural bias, have been compelled to give up, not only Triton, but many later forms of the power which for a time assumed his shape. Emptied of the hopes and pleasures flowing from such conceptions, we stand in more special need of all that Nature has to offer in the way of grandeur and beauty, of all that history has to offer in the way of strength and inspiration, and of such interpretations, by men of genius, of Nature, history, and contemporary life, as at this moment adorn these walls. If I might employ, in a sense so qualified as to render me sincere in using it, a form of language familiar to you all, I would say that we interpret these works of genius, these achievements in which our best men embody their highest efforts, as the outcome of the cultivated, but at the same time inborn and unpurchaseable gift of God. For, though the laborer be worthy of his hire, and though the leaders both in arts and science may now by good right make pleasant terms with the world, they reached the position which enables them to do this through periods of labor and resolute self-denial, during which their arts and their science were to them all in all; and reward was the necessary incident and not the motive power of their lives."

Mr. James Geikie, in a fourth paper on "Changes of Climate during the Glacial Epoch," thus states his views as to the sequence of climates in England during this time: First, a succession of alternate glacial and temperate conditions, but associated with the great continental ice-sheets; second, a temperate climate with removal of the ice-sheets from low grounds; third, a period of subsidence, with temperate climate, and much denudation of moraines; fourth, a period of emergence, with arctic conditions, floating ice dispersing erratics, and deposition of clays with arctic mollusca; and, fifth, a period of local glaciers in Britain and Ireland, with gradual amelioration of climate.

Dr. Cobhold says that, when once the trichina has gained admission to our muscles, all hopes of dislodging it are at an end; but, if a person suspects that he has eaten diseased or trichinized meat, he should lose no time in seeking assistance. Immediate advice, followed by suitable remedy, might be the means of saving his life, whereas a few days' delay would perhaps prove fatal. While the worms are in the intestinal canal, we can get rid of them; but, when once the trichinal brood migrates into the flesh, no means are known by which their expulsion can be effected.

A Berlin lithographer, after years of study, is said to have at last succeeded in producing a paper for printing money which it is impossible to imitate. The color of the paper is the only secret on which the invention rests. The inventor says the colors cannot be chemically analyzed; with the magnifying-glass they can be distinguished from all other colors, and in their quality as colors they cannot be imitated by photography, nor in any other way.