Popular Science Monthly/Volume 12/March 1878/Popular Miscellany

From Wikisource
Jump to: navigation, search
Popular Science Monthly Volume 12 March 1878  (1878) 
Popular Miscellany
 

POPULAR MISCELLANY.

The Last of the Gases.—The last of the gases that had never been condensed to liquids—oxygen, hydrogen, and nitrogen—have at length yielded to pertinacious experiment, and, under the joint influence of greater degrees of cold and pressure than had ever before been employed, have been reduced to the liquid form. This great experimental exploit has been performed by two chemists independently, and almost simultaneously—Raoul Pictet, of Geneva, and M. L. Cailletet, of Paris, by different processes. Pictet condensed oxygen, which was first announced; but Cailletet had already done it, and he also liquefied nitrogen, hydrogen, and the air. We give a representation of his apparatus, and an account of his processes, and shall give fuller statements of the results as they are more fully announced.

 

Stanley's Trip down the Congo.—The exploration of the Congo River from Nyangwe to the sea, by Henry M. Stanley, must be esteemed one of the most important achievements in the whole history of African discovery. He set out on November 5, 1876, from Nyangwe (latitude 4° 20' south, longitude 26° 40' east), at the head of a numerous band of native followers, marching northward by land forty miles, till he again came to the river—known here as the Ugarowa, or the Lualaba. Putting his men in canoes, and himself embarking on the portable Lady Alice, he commenced his long journey of alternate boating and portaging which lasted for nine months. The party soon began to experience the hostility of the native tribes, who again and again attacked them from the banks of the stream or in canoes. On December 6th seventy-two of Mr. Stanley's men were down with smallpox, which rendered defense all the more difficult; he seized a town, and there housed his sick and wounded, but for two days and nights he and his party had to repel the fierce attacks of the natives. Soon he was boating down the river again, his force on January 4th numbering 146 men. In latitude 0° 32' 36" south is a series of cataracts, and Stanley's men had to cut a road through the forest and drag their canoes round the falls, the natives constantly harassing them in the mean time. Just below these cataracts the river widens enormously, receiving several considerable affluents; its course, too, becomes westerly, though still tending toward the north till it reaches latitude 1° 40' north, longitude 23° east, when it takes a southwesterly direction to the sea. One of the great tributaries of the Congo below the cataracts is the Aruwini, supposed to be the Welle of Schweinfurth. Here, on Stanley's map, is the legend "The Cannibal Region," and a little to the south "The Region of Dwarfs." At one place the expedition was attacked by the cannibals in fifty-four canoes with paddles eight feet long, spearheaded and pointed with iron blades. Stanley's breech-loaders soon forced the enemy to retreat in confusion. After receiving, in latitude 0° 20' south, longitude 19° 40' east, the waters of a great river, Ikelembo, otherwise the Kasai, coming from the south, and a little below, another river from the north, the Congo flows southwesterly in a mighty stream, till at the mouth of the Kwango it is compressed between two ranges of hills. The rapids commence 180 miles above Yellala Falls, there being a series of sixty-two cataracts; these it took the party five months to pass. Mr. Stanley reached the coast on August 11th with the ragged and half-starved remnant of his followers, having followed the river for about 1,800 miles. They were received on board a British naval vessel, and the natives carried back to Zanzibar. Mr. Stanley himself has returned to England.

 

German Handicraft. — A correspondent of the Manufacturer’s Review, now visiting Germany, cites numerous facts confirming the criticisms passed by Prof. Reuleaux upon the quality of the work done by German artisans. Last winter, this writer occupied a room richly furnished and decorated, but hardly a day passed without some accident happening. The ornaments were all glued on, and one day it was the cornice of a wardrobe, another the slat of the dressing-table, that fell off. Not a single lock in the bureau would hold a drawer closed. On a windy night a match was extinguished by a gust of air coming through the double windows. This case was typical. "Whenever," says the author, "I had occasion to call in an artisan, the job was badly done, or delayed, or bungled. I never had a suit of clothes or a pair of boots that fitted." His experience extended over all Germany, both north and south, in small villages and towns up to 25,000 inhabitants, and it was everywhere the same. The best specimens of German manufacture are exported, as the home market requires cheap goods. Now, as the author remarks, Germany is preeminently the land of technical education, and the question naturally arises, "Is this the fruit of the system, and is the system itself a failure?" Various answers have been given: "It has been pointed out that as domestic industry has no use for them, a large number of the skilled, technically educated artisans and workmen emigrate to where their services are better appreciated, and that they are to be found in the workshops of Paris, London, and New York, occupying leading and well-paid positions. There is undoubtedly a great deal of truth in that, but it is also evident that it fails to cover the case; the cause must be deeper. It has been asserted, by men who certainly ought to know, that the instruction in German technical schools is too purely theoretic and scientific, and too little practical; that the professors, able men though they be, often have no practical knowledge of the arts of which they expound the underlying principles. It is evident that in this way the students, instead of being trained, are spoiled for their work. To illustrate, you need simply look at some of our American agricultural colleges; the professors may be excellent chemists, physicists, botanists, and zoölogists, but how many of them know practically anything about farming? It is thus that the question I have discussed has a practical bearing upon our own institutions. We are beginning to introduce technical schools everywhere, and we must guard against the danger mooted."

 

The Whitney Glacier. — While visiting the Pacific slope, on business of the United States Entomological Commission, Mr. A. S. Packard, Jr., ascended Mount Shasta, in Northern California, and studied the Whitney Glacier, one of the three glaciers on its flanks. The Whitney Glacier is about three miles long, and extends from the summit of Shasta peak down to or quite near the line of trees. The surface is white and clean near the top. Ice cascades and crevasses begin very near the upper termination. On the upper portion on the east side, under a perpendicular wall of rock, is a lateral moraine; and a little farther down, where the glacier abuts against the crater-cone of Mount Shasta, is a lateral moraine on the west side. The terminal moraine covers the bottom of the glacier, and connects the two lateral moraines. The end of the glacier, instead of being free of detritus, pushing the mass before it, as in most European glaciers, runs under the terminal moraine for a considerable distance, the ice here and there projecting above the surface of the moraine. At and beyond the end of the present terminal moraine lies the former extension of it, constituting naked plains; and below the still more ancient moraine, showing the former size of the glacier, and comprised of a series of well-wooded hills. A muddy stream runs north from the end of the glacier.

 

Sensitiveness of the Leaves of the Common Teasel.—On closely examining the glandular hairs of the leaves of the common teasel, Mr. Francis Darwin observed protruding from them translucent, highly-refracting threads, capable of spontaneous movement. These filaments were found to consist of protoplasm, containing a large amount of resinous matter. They not only possess the power of spontaneous movement, but can also be made to contract violently under the influence of sundry reagents, of temperature, electricity, or simple mechanical irritation. In nutritive fluids the movements are very remarkable. Thus, in an infusion of meat, the filaments became rounded or sausage-shaped, or very long and bulky; sometimes they coalesced with one another, or again became completely detached and floated freely in the fluid. The movements resemble the "aggregation movements" observed in the tentacles of the Drosera. Mr. Darwin is of the opinion that these anomalous structures are connected both with the production of resin and the absorption of nitrogenous matter. In the adult teasel the leaves form, by their union in pairs across the stem, large cups, in which water collects, and in which insects are caught. The decomposing bodies of these insects form with the water a strongly-nutritive fluid, which is absorbed by the gland-hairs and their filaments.

 

Gas as a Domestic Fuel.—Gas as a fuel for domestic use possesses many noteworthy advantages over all other kinds of fuel, and there is, apparently, nothing to hinder its universal substitution in place of grosser fuels, save its greater cost. By using a gas apparatus, we may do away with dust, smoke, ashes, cinders, and kindling-material, save time and labor, and escape many vexations. For summer use, gas-stoves possess special advantages even on the ground of economy. "It is desirable," says the American Gaslight Journal, "to keep as cool during the heated term as is consistent with the pecuniary and mechanical means at our command; therefore, we should have our artificial heat so arranged as to be used only when desired for active work, and employed no longer than is necessary. With a good apparatus, the gas actually used for cooking and performing all necessary fuel-labor, during the warm season, costs no more than the coal and kindling used for the same purposes, and we get the comfort, saving of time, convenience, and sanitary influence, thrown gratuitously into the trade." The case is different when it is proposed to employ gas for the purpose of warming houses. "It is," the Journal admits, "more expensive to run a gas-stove for a given amount of heat than it is to run a coal-stove for the same. Hence, when the heat is to be continuous, the coal-stove has the advantage so far as cost is concerned." Our contemporary then suggests to the gas companies the advisability of setting up in houses of gas-consumers a special metre connected with the heating and cooking apparatus, and of selling gas for these purposes at half-price, so as to encourage the use of gas in this way.

 

Impure Water fatal to Fish-Breeding.— Mr. Seth Green takes advantage of an accident which occurred lately at the State fish-ponds, to caution people against drawing off the water of old mill-ponds, except they do it very slowly, especially in warm weather. "Last week," he writes to Forest and Stream, "the State ponds at Caledonia came near losing all their breeding-fish. The head of the stream is about one mile above the ponds. Half of the water comes out of the ground at the head of the stream, and a dam was put across the creek sixty years ago, about forty rods from the spring, making a pond of several acres. It is full of moss and all sorts of animalcula. Last week the owner of the pond opened the gates, and let the water down with a rush. It killed all the trout in the stream for a half-mile below, and if it had not been for many large springs coming in on both sides of the creek, all the trout in the stream and ponds would have been killed, and it would take many years to restock the ponds as they now are." The different kinds of fish now in these ponds are California salmon, Kennebec salmon, brook-trout, salmon-trout, grayling, a hybrid of California salmon and brook-trout, also a hybrid between salmon-trout and white-fish.

 

Graves of the Mound-Builders.—On opening a sepulchral mound on Coup's Creek, Macoupin County, Illinois, four skeletons were found sitting two-and-two, with the arms crossed, and the knees of one pair pressing sharply against the backs of the other. The grave was six feet in length by three in width, and search was made for other remains. Nothing, however, was found, except four large marine shells, identified as of the Linnæan species Busycon perversum. The position of each of these shells in relation to the skeletons was the same: the smaller end of one had been placed in the right hand of each, while the larger portion rested in the hollow above the left hip. But what will appear most singular in this remarkable find is the fact that each shell contained what seemed to be the bones of an infant. "Within each of the shells," writes Mr. John Ford, in the "Proceedings" of the Academy of Natural Sciences of Philadelphia, "there had been packed what appeared to be the bones of a child; the skull, which evidently had been crushed before burial, protruding beyond the aperture. Of course, any hypothesis regarding the purpose of this peculiar rite must necessarily be of a conjectural character; nevertheless, it was difficult to resist the conclusion that these infants were sacrificial offerings to the spirits of the dead, whom the living desired to honor."

 

Non-Poisonous Coloring for Preserved Vegetables.—A patented process, for giving to cooked and preserved vegetables a green color, without the employment of copper or any other poisonous substance, is described as follows: First, the green leaves of some such plant as spinach, or sorrel, are scalded for a few minutes with boiling water, and drained; they are then triturated with knives or other cutting instruments. Next the triturated mass is heated with an equal weight of caustic soda solution marking 12.5° Beaumé, the mixture being boiled till the leaves are dissolved. From the product prepare a "lacker" by precipitating alum with this alkaline solution of chlorophyl, and then draw off and wash the precipitate in abundance of water, and finally press out the excess of water. To prepare the lacker for use, about thirty pounds of it is put in a basin with about fifteen pounds of soluble phosphates, especially phosphates of soda, potash, or ammonia, or of acid phosphates, or alkaline citrates, or double tartrates, and water is added until the liquor marks 2° to 5° Beaumé. To communicate the green color of this chlorophyl preparation to cooked or preserved vegetables, the latter have only to be immersed for a few minutes in the solution at a temperature of 212° Fahr. The effect of the operation is to impart to the products treated a fine, permanent green color, due to the absorption and fixation of an excess of chlorophyl.

 

Compressed Air in Coal-Mining.—An English journal gives an account of certain experiments recently made at Wigan to show how compressed air may be substituted for fiery explosives in coal-mining. A "cartridge," or reservoir, was placed in a shot-hole, after the manner of a charge of powder, and rammed or plugged in the same way. This chamber is in connection with a powerful air-pump, adapted expressly for the purpose, and, by simply turning a wheel, the collier can "fire his shot" without the least danger of setting fire to the inflammable gases. Mr. Marsh's (the inventor's) machine is capable of exerting a pressure of over 12,000 pounds to the square inch, and this force can be produced by two men turning the wheel in less than three minutes from the time of ramming the cartridge. The Wigan experiments show that very large quantities of coal can be brought down at a very much less expenditure of force. The first cartridge "fired" was burst at a pressure of 7,500 pounds to the square inch, the pressure being registered by a gauge. The coal was fractured, but not brought down; and a second cartridge was inserted, and burst at a pressure of 8,250 pounds to the square inch, completely loosening the coal and breaking up about eight tons. The whole force of the shot was probably not exerted on the seam, as the ramming was blown out. The machine is described as very handy and compact, and easily used, while the cost, beyond the first outlay, is absolutely nil.

 

The Heliotype Process.—For some years an eminent publishing-house in Boston has been engaged in the production of "heliotype" copies of famous works of art, and the public is now more or less familiar with the products of the "heliotype" process. But what that process is we have nowhere seen explained till recently a writer in the Tribune gave a very intelligible account of its modus operandi. In what follows we propose to give in brief the main points of the author's explanation: First a photographic negative is made in the ordinary manner; but the "positive" plate is peculiar. The basis of its composition is gelatine, with a mixture of bichromate of potash and chrome alum. This mixture is dissolved in hot water, and the solution is then poured on a plate of glass or metal, and left to dry. When dry it is about as thick as ordinary parchment, and is stripped from the plate and placed in contact with the previously prepared negative; the two are then exposed to the light. The bichromate of potash makes the gelatine plate sensitive to light, and wherever the light touches it the plate becomes leathery or water-proof. The result of the exposure to light is, therefore, that a portion of the gelatine plate— the image—is water-proofed, while the remainder is absorbent of water. Now, we know what a repulsion exists between water and greasy substances of every kind—for instance, printer's ink. It follows that, if we moisten the gelatine plate, the unchanged parts will absorb the water, and, if ink is then rolled over it, it will adhere only in the altered parts. By so applying ink, the sheet of gelatine is converted into a "positive" plate from which copies can be taken on a printing-press. This plate, strange to say, is very durable, and is capable of yielding, with fair treatment, several thousand impressions. Of course, the sheet of gelatine must have a solid base given to it, to hold it firmly on the bed of the press while printing. This is accomplished by uniting it under water with a metallic plate, exhausting the air between the two surfaces, and attaching them by atmospheric pressure.

 

Epidemics and Ablution.—A short time ago we published some remarks of Dr. Hebra, of Vienna, depreciatory of the value of frequent bathing. A diametrically opposite opinion is held by the eminent hygienic reformer, Edwin Chadwick, C. B., who cites facts to prove that skin-cleanliness, or in other words frequent ablution of the whole person, is a powerful preservative against all infectious and contagious diseases. He asserts that in children's institutions the death-rate and cases of sickness have been reduced one-third by regular head-to-foot ablutions with tepid water. Experienced trained nurses, regularly attending scarlatina-patients, give themselves regular head-to-foot ablutions twice a day, and a change of clothes once a day. Medical men of experience, who serve amid plagues and the most terrible epidemics, do the like. Mr. Chadwick adds: "If I had again to serve as a member of a general board, and had to exercise authority in providing defenses against epidemics, I would propose regulations for the immediate and general 'tubbing' of the population, and have it seen to as sedulously as vaccination for protection against smallpox." To show the influence of skin-cleanliness on the assimilation of food, Mr. Chadwick relates the following incident: "A friend of mine," he writes, "in command of a brigade in Spain, was hemmed in, and his men were put on very short rations; and to amuse them—it being summer-time—he encouraged them to bathe daily in a river close by, and he marked, as a result he had not expected, that his men were in as good strength as the unwashed soldiers on their full rations." Similar results are observable in the inmates of well kept prisons.

 

New Process of Embalming.—A new and inexpensive method of embalming has been invented by Dr. Lowell, of Brooklyn. The preservative fluid he employs is a solution of zinc chloride which is injected into the body either by an artery or a vein. The apparatus required consists of a porcelain-lined vessel, which is elevated to such a height that the solution may be injected into the cadaver after the manner of a gravity-syringe. For the passage of the preservative fluid from this receptacle into the vein of the cadaver, glass and rubber tubing is all that is required. Dr. Lowell writes: "The injection may be made by either artery or vein. ... I prefer the brachial artery above the elbow as the point for introduction of the glass tube, for the primary incision is slighter, and consequently divides smaller and fewer veins than when I expose the femoral artery. I use the gravity method, and introduce about five gallons of the antiseptic fluid. The effects are eminently satisfactory. The color of the integument is improved." A body treated in this way was transported from New York to Richmond last summer without odor, disfigurement, or external sign of decay.