Jump to content

Popular Science Monthly/Volume 10/April 1877/Popular Miscellany

From Wikisource

POPULAR MISCELLANY.

Tyndall and Roberts on Spontaneous Generation.—Dr. Bastian, in a communication to the Royal Society of London, last June, cited some experiments to show that, while an acid urine usually remains barren after being boiled a few minutes, it becomes fertile when similarly treated if previously neutralized by liquor potassæ, especially if it be afterward maintained at a temperature of 115° or 120° Fahr. But the significance of these results for the doctrine of spontaneous generation is proved to be very little indeed by Dr. William Roberts and Prof. Tyndall, both of whom show that Bastian's experiments only confirm the observation made by Pasteur more than fourteen years ago, that alkaline liquids are more difficult to sterilize than acid ones. They further show that such liquids, once effectually sterilized, according to methods which they describe, remain perfectly sterile when the access of life-germs from without is precluded. The addition of the alkali appears to enable the preëxisting germs in the urine to survive the process of ebullition. To prevent this conservative action of the liquor potassæ, and at the same time to have a mixture precisely the same as that experimented on by Bastian, Tyndall adopted the following mode of procedure, which is substantially identical with that adopted by Dr. Roberts: Small tubes, with their ends finely drawn out, were charged with a definite amount of caustic potash, and subjected for a quarter of an hour to a temperature of 220° Fahr. They were then introduced into flasks containing measured quantities of urine. The urine being boiled for five minutes, the flasks were hermetically sealed during ebullition. They were subsequently permitted to remain in a warm place sufficiently long to prove that the urine had been perfectly sterilized by the boiling. The flasks were then rudely shaken, so us to break the capillary ends of the potash-tubes and permit the liquor potassæ to mingle with the slightly acid liquid. The urine thus neutralized was subsequently exposed to a constant temperature of 122° Fahr., which is pronounced by Dr. Bastian to be specially potent as regards the generation of organisms.

Ten flasks, prepared as above described toward the end of last September, remained perfectly sterile for more than two months. There is no doubt that they would have remained so indefinitely.

Three retorts, moreover, similar to those employed by Dr. Bastian, and provided with potash-tubes, had fresh urine boiled in them on the 29th of September, the retorts being sealed during ebullition. Several days subsequently, the potash-tubes were broken, and the urine neutralized. Subjected for more than two months to a temperature of 122° Fahr., they failed to show any signs of life.

The Phenomena of Hypnotism.—Dr. Heubel, in Pflüger's Archiv, rejects Czermak's explanation of hypnotism (see The Popular Science Monthly, vol. iii., p. 618, vol. iv., p. 75), as also the explanation offered by Kircher and Preyer, and thinks that all previous investigators of this phenomenon have witnessed only its first stage—that which is most easily induced in animals of relatively high organization. Cold-blooded vertebrates, such as the frog, may be reduced to a state of complete immobility at will; they will remain in a constrained position for hours, instead of seconds or minutes. This abolition of voluntary movement and of consciousness is, according to the author, nothing but ordinary sleep. He holds that the waking state requires for its maintenance a continual stimulation of the higher nervous centres by impressions conveyed to them along the various centripetal nerve-fibres. By forcing an animal to remain motionless for a brief interval (without inflicting pain), and simultaneously excluding visual and auditory sensations from its brain, we suddenly deprive its nerve-centres of a large proportion of their accustomed stimuli. Accordingly, they are unable to remain awake, and their functional activity is only restored to them when they are roused by some impulse from without. Having satisfied himself in a variety of ways of the correctness of this explanation as applied to the phenomena exhibited by the frog, Heubel proceeds to extend his results to birds and mammals, and arrives at the conclusion that "forced sleep" will account for all the facts hitherto observed.

Further Experiments with Putrescible Fluids.—Mr. Dallinger has communicated to the Royal Microscopical Society of London some further results of his experiments with sterile putrescible fluids. In these experiments, an air-chamber after Tyndall's plan was used, and it was tested for motes by a beam of oxyhydrogen-light. The germs were obtained from a maceration of haddock's head that had been kept for fifteen months, and found to contain numbers of the "springing and calycine monads" of former papers, many of them in a condition for emitting spores. A portion of this material was evaporated at the temperature of 150°. Dust from it was diffused through the Tyndall chamber, and, after the heavier particles had settled, in the course of four and a half hours, ten small glass basins filled with Cohn's nutritive fluid, freshly prepared, were introduced, six being open and four covered with glass lids. In this condition they were left for twenty-four hours, and then the lids were removed from the four covered vessels. After four days, "calycine" monads were found in all the first six vessels, and, in smaller numbers, the "springing" sort. Two days later the four vessels were examined; in three there were no calycine monads, and very few in the fourth; all exhibited the springing monads. The reason of this is probably to be found in the fact that the germs of the calycine monads are larger than those of the springing sort, and settled down first from their state of suspension in the air.

A Solar Distillery.—M. Mouchot lately described, at a meeting of the Paris Academy of Sciences, a very convenient solar alembic. The mirror is fifty centimetres in diameter, and the kettle holds one litre of wine, which begins to boil on being exposed to the sun for not over half an hour. The vapor of alcohol is then condensed in a worm. The brandy thus obtained is very agreeable in flavor, no matter what kind of wine is used. It possesses an aroma resembling that of Kirschwasser. "It suffices," adds M. Mouchot, "to fill the kettle with water, and then to interpose between it and the worm a receptacle containing sweet-smelling leaves and flowers, in order to obtain all the essences yielded by distillation."

The Florida Cockroach new to American Science.—It is somewhat remarkable that, in certain parts of Florida, living is made almost impossible from the presence, in amazing numbers, of a cockroach not known North. The queer thing is that, while this pest has been long known in Florida, the fact has escaped the knowledge of scientific men. Mrs. Treat lately sent specimens to Prof. S. H. Scudder, the orthopterist, who was surprised to see them, and pronounces them the Periplaneta Australasia of Fabricius.

Meteorological.—A sixth paper by Prof. Loomis is published in the American Journal of Science for January, giving "results derived from an examination of the observations of the United States Signal Service." The object of this important series of papers is to generalize results, using as data the vast amount of observations made in all parts of the United States.

In this paper, Prof. Loomis considers first the period of unusual heat which occurred in June, 1873. The thermometer rose to 108° at one point—Fort Sully—and to 95° and 100° at other points, for several days in succession, indicating a temperature 20° above the mean for the month. The heated area was north of latitude 39°, and east of the Rocky Mountains, and advanced slowly eastward to Western New York.

It appears that the heat was over a well-defined area, which was also an area of depressed barometer. There was also a gentle movement of air from the south into that area, which accounts for some of the excess of heat; but the region where it arose—Colorado, Montana, and contiguous districts—was excessively dry. No northern winds occurred to cool the air, and Prof. Loomis thinks the great excess of heat may be attributed to the hot south winds already referred to, and, secondly, to the accumulated effects of the sun's radiation.

In the second part of the paper the movements, form, and distribution of rain areas south of latitude 36° are considered. When two or more inches of rain falls within eight continuous hours, we have a "great rainfall." It appears that such rainfalls do not usually continue more than eight hours, and only very rarely do they continue twenty-four hours, either at one station or at successive stations.

It is shown that, on the Gulf and Atlantic border, the great rainfalls are twice as frequent on the coast as at 200 miles inland from it. A cause assigned is the rising of the air from the ocean as it impinges upon the land, and the consequent condensation of its vapor. This movement of the air assumes a cycloidal direction, as was found to be the case in a great number of instances, the motion being from right to left, in the direction contrary to that of the hands of a watch. "Hence, every great rain-storm should be accompanied by an inward and cycloidal motion of the air."

In the distribution of fifty-two cases of great rainfall by seasons, it was found that forty occurred in summer and autumn to twelve in winter and spring. Northward of latitude 36° the difference was still greater, being as five to one. It is thus shown that great rainfalls are most frequent when the sun's heat is greatest, and the air contains most vapor.

The hours of the day have a direct relation to great rainfalls. Thus, they most frequently occur before 4.35 p. m., and seldomest at 11 p. m.; only eight out of fifty-two instances are reported by the night observations made at 11 p. m.

The area of greatest rainfall is found to be within that of the cycloidal movement of air, but not at the centre of low pressure. It is almost invariably eastward from it, sometimes more than 250 miles. Thus, a storm-area, as previously shown by Prof. Loomis, usually assumes an oblong shape, the long radius of which is ahead of the storm, in or near the general direction of its motion.

At stations northward of latitude 36°, observations show that great rains are accompanied by easterly winds; but, at the more southern stations of the district, the winds are north of east; while, at the northern stations, the winds are from south of east. When the wind blows from any other quarter, it is usually light.

This paper, like others previously published, presents, with the diagrams which have been published with them, the general phenomena of atmospheric movements with clearness and precision, and will speedily supersede the vague speculations concerning them which have so much occupied the public mind.

A Rapacious Fish.—The Serrasalmo piraya, found in all the rivers of Guiana, is doubtless one of the most voracious of fishes. The genus Serrasalmo (literally "serrated salmon," because of the double row of serratures on the belly) can hardly be classed with Salmonidæ, from which they differ both in general appearance and in habits. The S. piraya is a small fish, seldom exceeding one foot in length, but yet there is no animal that it will not attack, man not excepted. Alligators, horses, as well as fishes oftentimes ten times their own weight, are preyed upon by the pirayas. In attacking a fish they begin at the caudal fin, and the victim, being thus left without the principal organ of motion, is devoured with ease, several pirayas sharing in the meal. They often bite a piece out of a horse's leg when passing through the water. The feet of ducks and geese which are kept in the neighborhood where pirayas are plentiful, are almost invariably cut off, and the young ones devoured. In such localities it is unsafe to bathe, or even to wash clothes, in the river, many cases having occurred of fingers and toes being cut off by them. Schomburgek, in his "Travels in South America," from which most of these particulars have been derived, states that these fishes are "caught with hook and line, and their greediness is so great that no art is necessary to conceal the bait. The hook may be baited with a piece of fish, bird, or animal, or merely their entrails; the piraya will dart at it the instant it is thrown into the water, and seize it with eagerness, but it frequently happens that with its sharp teeth it bites the line, and escapes with the hook in its mouth. We, therefore, surrounded the line where it was fixed to the hook, the length of two or three inches, with tin or lead, and though it had a clumsy appearance we were not less successful. Some precaution is necessary even after the fish has been lifted out of the water, or it will inflict in its struggles serious wounds; the angler has, therefore, a small bludgeon ready, wherewith its skull is broken."

Science and Ventilation.—Sundry members of the Paris Academy of Sciences, at a recent session, expressed themselves very strongly as to the defective ventilation of the hall in which their meetings are held. Said M. Bouley: "The air here is unfit to breathe; the thing admits of no excuse; instead of gas, I wish we had again candles, as in former times." M. Leverrier: "I asked for lighting with gas, but I had also asked for another mode of ventilation; but, with regard to this, there has been no change. However, General Morin is a member of the Academy, and, in eight days, proper apparatus for ventilation might be set up, if we so wished." General Morin: "Eight days! Ten years ago, the setting up of such apparatus was in principle decided on." Leverrier: "The present condition of things is simply disgraceful; no other hall is so badly ventilated as the hall of the Institute." The eminent astronomer, were he to inspect critically the assembly halls of scientific and legislative bodies in other countries, would doubtless find abundant reason for retracting this severe judgment.

Intestinal Calculi in Horses.—In England and Continental Europe large numbers of horses die annually from the effects of calculi in the large intestine or in the cæcum. Of these calculi, Dr. T. L. Phipson writes in the Chemical News that they often begin by being triangular, or sometimes perfectly square, with rounded edges and corners, and become finally circular. In all cases they are formed of highly-crystalline concentric layers, and attain to eighteen or twenty inches in diameter. This, he thinks, is the greatest size they can attain. When so large as this, they press out the sides of the intestine, producing inflammation and violent pain, which causes the animal to roll about in agony, and, sooner or later, kills him. They consist mostly of phosphate of ammonia and magnesia, and the amount of organic matter is not great. This salt the author refers to the grain fed to the animals, and he raises the question whether grain is not for the horse a highly-artificial food. He is of the opinion that repeated doses of very dilute hydrochloric acid, say two to five per cent., in water or spirit, if it can be made to reach them, would quickly destroy the largest of these calculi. The lime in the water drunk by horses has nothing to do with the production of these concretions. It originates in the food, and is, in a large measure, due to a want of salt in the grain. Hence, working-horses that are highly fed should have lumps of salt to lick, and have salt in their food, and plenty of water to drink. The ventilation and drainage of stables is another important consideration. Many valuable beasts, after a hard day's work, pass the night in an atmosphere loaded with fumes of ammonia.

Abnormal Fruits.—Some abnormal fruits of the pear-tree, in appearance like very large acorns, having been exhibited at a meeting of the Academy of Natural Sciences of Philadelphia, Mr. Meehan took occasion to explain that a fruit is a modification of both leaves and branch. When a bud, he said, is being formed in the apple, pear, or similar trees, it may finally be either a flower-bud or a bud producing a new branch. Varying phases of nutrition decide this question. Exactly the nature of this variation we do not know; but we do know that the growth-force in the bud is arrested by some law of nutrition, and, instead of an elongated branch, what would be its series of spirals are drawn together closely, and the whole modified and made to form a flower. Thus, in the pear, it takes five buds to form one full cycle on a branch. When growth is arrested to form a flower, this first cycle is transformed into a five-lobed calyx, and generally this becomes much enlarged and fleshy, and covers all the other cycles of buds, which go to make up the inner layer of flesh terminating in the petals, carpels, or core, and so on. In the case under consideration the arresting force was imperfect. It had succeeded in forming the outer or calycine verticillate series of buds into a fleshy matter, giving what here might be called the cup of the "acorn;" but then the accelerating or branch-producing force gained a temporary advantage, and pushed on, forming the acorn-like centre, but only to be soon again arrested. This abnormal pear was, indeed, nothing more than an effort of the tree to produce a branch after a fruit had been decided on—a struggle which was finally decided in favor of the fruit.

Explanation of the Ball-Paradox.—Reuleaux offers the following explanation of the curious phenomenon of a ball being sup ported in air by a strong air-current directed obliquely upon it at an angle of 35° to 40° from the vertical: The pretty thin air-current, on reaching the ball, is deflected on all sides, and therefore more or less rarefied in its interior. Accordingly, the atmosphere presses the ball in the direction of greatest rarefaction, or the mean force of the rarefactions, toward the orifice. The weight of the ball acts vertically downward. Equilibrium occurs between the obliquely acting force of the current and the two forces just named, when the mean force of the latter is parallel to the action of the current. This can only take place when the ball has its centre under the axis of the current. There are then two forces which put the ball in rotation. If the finger or a rod be brought to the place of supposed minimum pressure on the ball, the latter is forthwith driven off (the vacuum being destroyed), or falls down.

Successful Case of Transfusion of Blood.—A case of successful transfusion of blood is recorded in the Lancet. The patient, a clerk, twenty years of age, was completely demented, hyperæmic, anæsthetic, and cataleptic; refused all food; dribbled constantly. The pulse was very feeble, rate 70, respiration 24. His state was one of profound anæmia. A student in St. Thomas's Hospital volunteered to supply the blood for the operation. The patient received 200 grammes of blood without showing any bad symptoms; he even gave evidence of being roused from his habitual torpor. Three hours after the operation, the patient, who had, in the mean time, been placed in a warm bed, and had taken doses of tea and brandy, had a full pulse, rate 90, respiration 28. He answered to his name and spoke a few words, rubbed his face with one of his hands, opened his eyes, and swallowed voluntarily. Five hours later the pulse was 100, strong, respiration 30. The following day the pulse was 96 and respiration 28, and the patient ate and drank well and often. Toward evening the pulse was 90, respiration 28, and he spoke and answered slowly when spoken to; said he had no pain. Four days later the symptoms still continued to be favorable. The process of transfusion was to be repeated by the physicians, the results being so encouraging.

Production of Sulphurous Acid for Use as a Disinfectant.—Sulphur-fumes (sulphurous acid) have from time immemorial been employed to fumigate and purify infected air, but the ordinary method of producing the fumes by burning sulphur is cumbrous and very uncertain. Mr. T. W. Keates offers in the Lancet a ready and simple means of effecting this object. Instead of sulphur, he proposes to use bisulphide of carbon, a compound consisting of two atoms of sulphur and one of carbon. It is a dense, mobile liquid, heavier than water, and intensely inflammable. During combustion the constituents of the bisulphide combine with the oxygen of the air, producing sulphurous and carbonic-acid gases, the former greatly exceeding the latter in quantity. The bisulphide can be burned in a common spirit-lamp, or it may be mixed with oils and burned in an oil or kerosene lamp. Any proportionate quantity of sulphurous acid can in this way be thrown into an atmosphere, and the action may be continued for any length of time. As bisulphide of carbon is extremely volatile, the lamp should be furnished with a well-fitting screw-cap, to prevent loss by evaporation.

A Fishing-Spider.—"Just before the late war," writes the author of a communication in the American Naturalist, "I was at Colonel Oakley Bynum's spring, in Lawrence County, Alabama, near the town of Courtland, where I saw a school of minnows playing in the sunshine near the edge of the water. All at once, a spider, as large as the end of my finger, dropped down among them from a tree hanging over the spring. The spider seized one of the minnows near the head. The fish thus seized was about three inches long. As soon as it was seized by its captor, it swam round swiftly in the water, and frequently dived to the bottom, yet the spider held on to it; finally, it came to the top, turned upon its back, and died. It seemed to have been bitten or wounded on the back of the neck near where the head joins. When the fish was dead, the spider moved off with it to the shore. The limb of the tree from which the spider must have fallen was between ten and fifteen feet above the water. Its success shows that it had the judgment of a practical engineer."

Qualitative Determination of Potassa.—Carnot offers a new and simple process for the qualitative detection and the determination of potassa, hitherto one of the most delicate operations in analytical chemistry. It is as follows: In a few drops of hydrochloric acid, one part of the subnitrate of bismuth, say half a gramme, is dissolved, and then, in a few cubic centimetres of water, are dissolved about two parts (one gramme to one and a quarter) of crystallized hyposulphite of soda. The second solution is poured into the first, and concentrated alcohol added in large excess. This mixture is the reagent. If brought in contact with a few drops of the solution of a potash salt, it at once gives a yellow precipitate. With an undissolved potassic salt it produces a decidedly yellow coloration, easily recognized. All potassic salts with mineral acids are susceptible of this reaction; it is also very sensitive with the organic salts—tartrates, citrates, etc. The reaction is not interfered with by the presence of other bases, with which nothing analogous is produced. The character is therefore perfectly distinct. Baryta and strontia alone may occasion some difficulty by reason of the white precipitates of double hyposulphites, which they form with the same reagent; but it is very rare to meet them along with potassa, and they are very easily detected and removed.

Prevention of Fires in Coal-Mines.—In an address on fires in mines, Mr. Richard P. Rothwell affirms that the most efficient preventives of such fires, from whatever cause they may come, are to be found in education, in increased knowledge of the causes of fires, and a better appreciation of the working of these causes. Mine-managers he would compel to undergo strict examinations, nor would he allow any one to undertake the responsible duties of this place without a certificate of competency from a qualified board of examiners. He would not, however, stop here, but would have the miners themselves instructed as to the causes and preventives of the dangers they meet with in their work. Special free instruction upon these points might be furnished at every colliery; and this could doubtless be accomplished by encouraging the giving of popular lectures, by practical miners and engineers, on subjects of interest to the miner, and by giving small prizes to those who pass the best examination on subjects of daily practical application in their calling. Greater knowledge always makes better workers, and mine-owners would find in this a good return for the expense incurred.

Economy of the Electric Light.—In a series of experiments on electric light, Prof. W. A. Anthony used an electro-magnetic machine of the Gramme pattern, driven by a five-horse Brayton petroleum-engine. The engine consumed a little over 612 pounds of crude petroleum per hour. The lamp used in the engine, by which the explosive mixture is fired, had a one-inch flat wick, and consumed 29.8 grammes (459 grains) of oil per hour. The power resulting from the motion of the engine, when applied to the electric machine, produced a stream of electricity or electric light having an illuminating power equal to that of 234 of the lamps mentioned, showing that three times more light may be produced from a given quantity of oil, if its energy is converted first into mechanical power and then into electricity, than if the oil is directly burned in a lamp.

Southern Illinois Academy of Science.—The Southern Illinois Academy of Science, a newly founded scientific association, with its seat at Carbondale, has for its objects the investigation—1. Of the ethnology and history of Southern Illinois, including its antiquities and aboriginal remains; 2. The geology, botany, and zoölogy, of that section; and, 3. To encourage the production of original papers on the above, and on special mathematical, astronomical, and meteorological subjects, as well as on the origin and meaning of the names given to localities by the Indians and the first white settlers of the country. The Academy is engaged in making a collection of materials illustrative of the field of research to which it has devoted itself, and has issued a circular calling for contributions of archaeological and aboriginal remains, historical notes, maps, sketches of mounds, natural history specimens, etc. The Secretary of the Academy is Prof. Granville F. Foster, Carbondale, Illinois.

Threatened Eruption of Mount Vesuvius.—For many weeks Mount Vesuvius has been threatening an eruption. Prof. Boyd Dawkins, who visited the volcano in January, found, on arriving at the mouth of the crater, that it was filled with dense vapor like a fog. A low, roaring noise could be heard, and occasionally there was a flash of light, probably the reflected glare of the lava surging about in the volcano. Undismayed by these symptoms of internal disturbance, Prof. Dawkins went down seven or eight feet below the crater's edge, and found that he could light pieces of paper in holes which he dug with his hammer in the black ash on the inside. He is of the opinion that Vesuvius performs the duty of a safety-valve to a very large portion of the earth. At present the mountain is in a very restless state, and there may be an outbreak at any moment. The event is looked for with great interest by the inhabitants of Naples, as it will bring sight-seers from all parts of the world to their city.

The Challenger Collection.—The collections of marine animals made by the Challenger Expedition are declared by Prof. Agassiz to be in a better state of preservation, and their localities more accurately noted, than is the case with any similar collection he has seen. To give an idea of the magnitude of the Challenger collections, he says that if a single individual, possessing the knowledge of the eighteen or twenty specialists in whose hands they are to be placed, were to work them up, he would require from seventy to seventy-five years of hard work to bring out the results which the careful study of the different departments ought to yield. At the same time Prof. Agassiz observes that little that is new has been added by the Challenger Expedition to the deep-sea fauna as developed by the American and English Expeditions of 1866 and 1869. Reasoning from these premises, "we may safely say that while any new expeditions will undoubtedly clear up many of the points left doubtful by the Challenger, and may carry out special lines of investigation only partly sketched out, yet we can hardly expect them to do more than fill out the grand outlines laid down by the great English Expedition."

Preservation of Ice in the Sick-Room.—Dr. Gamgee, in the Lancet, suggests a good method of preserving ice in small quantity for a considerable time at the bedside of a sick person. His practice is to cut a piece of flannel about nine inches square, and secure it by ligature round the mouth of an ordinary tumbler, so as to leave a cup-shaped depression of flannel within the tumbler to about half its depth. In the flannel cup so constructed pieces of ice may be preserved many hours, all the longer if a piece of flannel from four to five inches square be used as a loose cover to the ice-cups. Cheap flannel, with comparatively open meshes, is preferable, as the water easily drains through it, and the ice is thus kept quite dry. When good flannel with close texture is employed, a small hole must be made in the bottom of the flannel cup, otherwise it holds the water, and facilitates the melting of the ice. In a room with a temperature of 60° Fahr., Dr. Gamgee made the following experiments with four tumblers, placing in each two ounces of ice broken into small pieces. In tumbler No. 1 the ice was loose. It had all melted in two hours and fifty-five minutes. In tumbler No. 2 the ice was suspended in the tumbler in a cup made, as above described, of good Welsh flannel. In five hours and a quarter the flannel cup was more than half filled with water, with some pieces of ice floating in it; in another hour and a quarter the flannel cup was nearly filled with water, and no ice remained. In tumbler No. 3 the ice was suspended in a flannel cup made in the same manner and of the same material as in No. 2; but in No. 3 a hole capable of admitting a quill pen had been made in the bottom of the flannel cup, with the effect of protracting the total liquefaction of the ice to a period of eight hours and three-quarters. In tumbler No. 4 the ice was placed in a flannel cup made, as above described, of cheap, open flannel, which allowed the water to drain through very readily. Ten hours and ten minutes elapsed before all this ice had melted.

Grote's Theory of the Peopling of America.—Prof. Grote's theory of the original peopling of America, as stated in recent papers, is that the original inhabitants came from Asia by way of the north during the latter part of the Miocene or earlier part of the Pliocene, and that this Tertiary population spread to the south along the mountainous backbone of the two Americas; that, on the advent of the Glacial epoch, the people then living in the extreme north were modified by the change in climate and were brought down by the ice and followed it back again to the arctic circle, and that the present representatives of glacial man are the Esquimaux. Through a study of migrations Prof. Grote comes to the conclusion that the ice must have acted as a barrier to further communication between the two continents of Asia and North America, and consequently that the civilizations of Central America and of the mound-builders are indigenous. Grote concludes that the theory of an accidental migration from Asia during the Quaternary cannot be supported in view of recently-ascertained facts. In a letter dated February 11, 1877, Captain E. L. Berthoud (of the School of Mines at Golden, Colorado), who has studied the geology and archæology of the West since 1859, writes that Grote's theory "solves many knotty points in the antiquities and prehistoric vestiges of Colorado." Captain Berthoud believes, from his observations, that man existed in the Rocky Mountain region prior to the deposit of gold in the Colorado mountain-slopes, Creek, Bar, and Placer diggings, about latitude 39° 30' to 41° north. Captain Berthoud has not only found flint tools and chips in the gold-bearing glacial drift, with remains of fossil elephants, but also in the drift of older date below this gold-bearing drift. Flint tools have been also found in company with estuary shells of not later age than older Pliocene as determined by Prof. Conrad.

The Decline of Savage Races.—Virchow, in an address upon the present position of anthropology, makes a few very just observations upon the subject of the decline of savage races in the presence of civilized man. Thus he remarks that we must not, in the case of an entirely isolated people, judge of their capacity for culture from the signs of it which exist. The extinction of uncultured races, he thinks, is rather to be ascribed to the barbarousness of Europeans, and to their incapacity to educate savages. There is no evidence that uncivilized races must become extinct—indeed, the contrary is proved by the history of Europeans themselves. If the civilized people of the present day are the product of a higher development, we cannot regard the possibility of such a development as a cause of the extinction of races in the same stage of culture once occupied by ourselves.

Estimation of Alcohol in a Watery Mixture.—Dr. Werner Siemens has designed an ingenious apparatus, by which a stream composed of alcohol and water, mixed in any proportion, is so measured that one train of counter-wheels records the volume of the mixture, while a second counter gives a true record of the amount of absolute alcohol contained in it. The principle is described as follows: The volume of liquid is passed through a revolving drum, divided into three compartments by radial divisions, and not dissimilar in appearance to an ordinary wet gas-meter. The revolutions of this drum produce a record of the total volume of passing liquid. The liquid on its way to the measuring-drum passes through a receiver containing a float of thin metal filled with proof-spirit, which float is partially supported by means of a carefully-adjusted spring, and its position determines that of a lever, the angular position of which causes the alcohol-counter to rotate more or less for every revolution of the measuring-drum. Thus, if water only passes through the apparatus, the lever stands at its lowest position, and then the rotative motion is not communicated to the alcohol-counter, and this motion is rendered strictly proportionate to the alcohol contained in the liquid, allowance being made in the instrument for the change of volume due to chemical affinity between the two liquids.

Preservation of Iron against Rust.—We find in Van Nostrand's Engineering Magazine an account of Dr. William H. Sterling's process for preventing the rusting of iron. The principle of this system, we are informed, consists in the saturation of the iron with a non-oxidizing or non-oxidizable substance while the iron is in a properly heated and expanded condition, produced by heating in a vacuum or in a simple chamber. One method of applying this system is given as follows by the inventor: "A vessel of iron, or any suitable material of sufficient strength, is made in the form and size best adapted to the shape and dimensions of the iron which is to be treated, with the lid so constructed that the vessel may be closed hermetically, and at the bottom suitable pipes are arranged for conveying steam and water alternately, for the purpose of heating and cooling the interior." Suitably connected with this vessel is a power-pump to produce the necessary pressure, also appliances for obtaining a vacuum. The iron is now heated to the desired degree and placed in the vessel, the top closed hermetically and superheated steam turned into the pipes at the bottom, to keep the metal at the required temperature; at the same time an atmospheric vacuum is produced by an ordinary air-pump connected with the chamber; the proper quantity of pure paraffine, having been also previously heated, is now let into this chamber and forced under pressure into the interstices of the iron, saturating it. When the iron has remained under this liquid pressure a sufficient time, it is gradually cooled by turning cold water instead of steam into the pipes, the pressure being kept up, however, until the iron is cool.

Destruction of Birds by Telegraph-Wires.—It is the opinion of Dr. Elliott Coues that in the United States many hundred thousands of birds are yearly killed by telegraph-wires. To show that this estimate is not extravagant, he cites his own observation while journeying on horseback from Denver, Colorado, to Cheyenne, Wyoming, the road for a considerable part of the way coinciding with the line of the telegraph. The most abundant birds of that region at the time (October) were horned larks and Maccown's bunting. "Almost immediately upon riding by the telegraph-wire," writes Dr. Coues in the American Naturalist, "I noticed a dead lark; and as I passed several more in quick succession, my attention was aroused. The position of the dead birds enabled me to trace cause and effect before I actually witnessed a case of the killing. The bodies lay in every instance nearly or directly beneath the wire. A crippled bird was occasionally seen fluttering along the road. Becoming interested in the matter, I began to count, and desisted only after actually counting one hundred in the course of one hour's leisurely riding—representing perhaps a distance of three miles." During the hour he saw three birds strike the wire; of these one had a wing broken, and another was dying in convulsions.

Natural History on the Great Lakes.—Prof. Comstock, of Cornell University, proposes to organize an aquatic school of natural history for work during the summer along the shores of Lakes Erie, Huron, and Superior. A steamer is to be chartered for the use of the school, and inland excursions are to be made to the mining regions and other points of scientific interest. A strong corps of instructors for zoölogy, botany, geology, etc., will be engaged, and collections will be made illustrative of the work done in these various departments. A portion of the collection will be the property of the students, while the remainder will be disposed of to such local societies, colleges, and schools, as may desire to purchase them in advance by taking shares at $10 each. The terms for admission to the school are very reasonable, viz., not to exceed $125 for thirty days, and $3.50 for each additional day. This, however, does not include the expenses of inland trips: such trips will only be made by such pupils as desire to take part in them, and will be so arranged as to require the least possible expenditure.

Winter-Quarters in the Arctic Regions.—The ship Discovery, of last year's British Arctic Expedition, wintered in latitude 81° 40' north, longitude 64° 30' west, in a well-sheltered inlet directly opposite to the winter-quarters of the Polaris. Here she lay imbedded in the ice for ten months and a half. In preparation for the long winter, a layer of snow ten or twelve inches thick was laid on the deck, but as it was found not to bind, it was mixed with ashes and water, and soon made a good macadamized road. Then snow was piled up outside the ship about fifteen or twenty feet thick. This and the layer on deck kept the warmth in the ship, and the temperature in the lower deck ranged from 48° to 56°. Between April 26th and October 16th the ship's company shot thirty-two musk-oxen, thirty-six hares, six seals, and five eider-duck—about four months' rations of fresh meat. Captain Stevenson, commander of the Discovery, considers the long winter the most enjoyable time of the whole period spent in the arctic regions, the ship being very warm and comfortable, and all hands employed in the work most interesting to themselves.

Voice of the Elephant.—According to Major Leveson, author of "Sport in Many Lands," elephants utter four distinct sounds, each of which is indicative of a certain meaning. The first is a shrill whistling noise, produced by blowing through the trunk; this denotes satisfaction. The second is the note of alarm or surprise, a sound made by the mouth; it may be represented thus: pr-rut, pr-rut! The third is a trumpeting noise indicative of anger; when the animals are very much enraged, or when they are charging an assailant, this sound changes into a hoarse roar or terrific scream. The fourth sound betokens dissatisfaction or distress; it is repeated frequently when an elephant is separated from the herd, or is tired, hungry, or overloaded; it may be thus imitated: urmph, urmph.