Popular Science Monthly/Volume 16/November 1879/Popular Miscellany
Experiments with Platinum.—A paper by Mr. Edison, on the behavior of platinum under the influence of the electric current, was read at the last meeting of the American Association by Professor F. R. Upham, the author being absent. Having found that a platinum wire, heated by the electric current and suspended in the air, loses weight in proportion to its mass, its heat, and the length of time during which the current passes through it, Mr. Edison took a platinum wire 20 of an inch in diameter, and wound it in the form of a spiral one eighth of an inch in diameter and one half inch in length. The two ends of the spiral were secured to clamping-posts, and the whole then covered with a small glass shade. After the spiral had been made incandescent for twenty minutes, the shade opposite to the spiral on both sides was slightly darkened, and after five hours was no longer transparent, a film of the metal having been deposited on it. Mr. Edison is convinced that this effect, namely, the loss of weight in the spiral, is due to the washing action of the air, to the wearing away of the surface of the platinum by the impact of the stream of gases upon the highly incandescent surface, and not to volatilization. That this supposition is correct is shown by the very different behavior of platinum wire in vacuo. Mr. Edison placed a spiral of platinum in the receiver of a common air-pump, and arranged it so that the current could pass through it while the receiver was being exhausted. At the pressure of two millimetres the spiral was kept incandescent for two hours before the deposit on the glass shade became visible. In another experiment, when the exhaustion was higher, the deposit became visible only after five hours. The same paper contained observations on other phenomena of still greater interest. It has been known for some time that platinum, when long subjected to a high temperature, becomes disintegrated. A platinum wire which has been heated to incandescence for twenty minutes, on being examined under a microscope, is seen to be full of cracks, and appears shrunken. If the current is continued for a considerable time the wire will fall to pieces. Now, Mr. Edison finds that this shrinking and cracking of the wire are due entirely to the expansion of the air in the pores of the metal, and its contraction on the escape of the air. If these air-spaces be previously eliminated, the platinum can be heated to incandescence without disintegration. How this is to be done is best told in Mr. Edison's own words:
"I had made a large number of platinum spirals, all of the same size and from the same quality of wire; each spiral presented to the air a radiating surface of three sixteenths of an inch; five of these were brought by the electric current up to the melting-point, the light was measured by a photometer, and the average light was equal to four standard candles for each spiral just at the melting-point. One of the same kind of spirals was placed in the receiver of an air-pump and the air exhausted to two millimetres; a weak current was then passed through the wire slightly to warm it for the purpose of assisting the passage of the air from the pores of the metal into the vacuum. The temperature of the wire was gradually augmented at intervals of ten minutes until it became red. The object of slowly increasing the temperature was to allow the air to pass out gradually and not explosively. Afterward the current was increased at intervals of fifteen minutes. Before each increase in the current the wire was allowed to cool, and the contraction and expansion at these high temperatures caused the wire to weld together at the point previously containing air. In one hour and forty minutes this spiral had reached such a temperature without melting that it was giving a light of twenty-five standard candles, whereas it would undoubtedly have melted before it gave a light of five candles had it not been put through the above process. Several more spirals were afterward tried, with the same result. One spiral, which had been brought to these high temperatures more slowly, gave a light equal to thirty standard candles. In the open air this spiral gave nearly the same light, although it required more current to keep it at the same temperature. Upon examination of these spirals, which had passed through the vacuum process, by the aid of a microscope, no cracks were visible; the wire had become as white as silver, and had a polish which could not be given it by any other means. The wire had a less diameter than before treatment, and it was exceedingly difficult to melt in the oxyhydrogen flame. As compared with untreated platinum, it was found that it was as hard as the steel wire used in pianos, and that it could not be annealed at any temperature."
Animal Mounds in the Pyrenees.—An interesting paper was read by Dr. Phené at the last meeting of the British Association, on a discovery of animal mounds in the Pyrenees. The author said that this discovery was, in a great measure, due to the description given by Sir Vincent Eyre in 1869 of a remarkable custom of burning living serpents at a particular spot in the Pyrenees, While investigating the region around this place of immolation, Dr. Phené found in certain directions indications which always accompany animal mounds. The churches abounded in features expressive of the subversion of a pagan faith, of which the serpent or dragon had evidently been the central point. Following the track where these indications were plainest, he had some upon mounds as distinct in resemblance to animal forms as any of the American mounds: they were altogether artificial, and shaped into an appearance of animal outline so real as to seem like life. In the parts forming the heads the chamber had been replaced by an arched chamber of Roman work, in another by a descent of several feet into the body of a small church. On the spire of the best preserved animal mound had been a tumulus in which, the curé of the church informed Dr. Phené, had been found several of the most primitive cinerary urns, containing bones, Celtic articles, and above them objects of the Gallo-Roman description, and again above these later or Christian Roman works. One of the most interesting of the latter had been laid aside, and the curé sought it out for Dr. Phené among some débris; it was the stem of an ancient cross, and on it were sculptured serpents—not in the usual position of subjection to a superior power, but evidently as being in a condition of supremacy; but, as there were also several dead ones represented, it might be that the sculpture figured the condition of the real serpents before and after the ceremony of burning. In the district there were many emblems of the serpent or dragon, and the mounds were distinctly of such a form. On the mountains overlooking these mounds were a number of stone circles, like those so well known in Britain, Dr. Phené promised to give further details in a paper which he was to have read before the Congress of Americanists at Brussels.
Carl Vogt on the Archæopteryx.—The Congress of Swiss Naturalists held its sixty-second annual meeting this year at St. Gall. Professor Carl Vogt delivered one of the public lectures, choosing for his subject the archaeopteryx, an animal intermediate between birds and reptiles. Of the archæopteryx there exist only two (fossil) specimens, one of which, that first discovered, is in the British Museum; the other, which is by far the more perfect of the two, was discovered a few years ago at Solenhofen, Germany. It is the property of Dr. Haeberlein, of Pappenheim. It was once fondly hoped that the Emperor of Germany would purchase this treasure and preserve it for the Fatherland; but, as Professor Vogt remarks, a petrified cannon or musket would have found infinitely more favor in that quarter! The naturalists who studied the specimen in the British Museum pronounced this Jurassic animal to be a bird, inasmuch as it had a beak, nails, and feathers. But the Solenhofen archæopteryx proves, undoubtedly, that the animal was a bird-like reptile, of the size of a pigeon, which had both scales and feathers, a beak provided with teeth, armed wings, bird-like feet with nails, and a reptilian tail, consisting of twenty vertebræ.
Stilling the Waves with Oil.—A few months ago we printed some observations on the use of oil as a means of calming a tempestuous sea in cases of danger to mariners. A later number of the journal (Chambers's) from which those observations were quoted contains the official report of a ship-master, whose vessel appears to have escaped disaster through the timely use of oil in a storm. This report was sent to "Chambers's Journal" by Mr. Sprunt, British Vice-Consul at Wilmington, North Carolina. It is as follows:
"British brigantine Gem, of Sackville, New Brunswick, Richardson, master. On the 1st of April last, bound from Wilmington, North Carolina, for Bristol, took a heavy gale of wind about a degree to the eastward of Bermuda, from the south, veering rapidly to the northwest, whence it blew a hurricane for thirty-six hours, with a cross-breaking sea, ship laboring heavily—'started' the after-house and boats, stove lazarette hatch, and took try-sail from the mast. All hands aft in the cabin in case the sea should break over and carry away fore-house. 8 p. m., sea getting worse, the master thought of resorting to the oil experiment, which he had read of in 'Chambers's Journal.' Had a canvas bag prepared, holding about three quarts of kerosene oil, with a rope of six fathoms attached, and kept trailing to windward; the oil leaking through the canvas greatly broke topping sea, and made matters much more favorable for the ship. This was kept up through the night; and at 3 a. m. on the 2d of April the weather began to moderate. The mate, who had himself lashed to the rigging during the whole of his watch, believed with the captain that the resort to the oil saved the ship, as such fearful weather had never during the captain's experience of fourteen years been witnessed by him. A drop of the oil will smooth about four feet circumference of sea. Captain Richardson suggests that a canvas bag to hold about six gallons is the best size, pierced with small holes with a penknife, the holes to be enlarged as the canvas becomes wet and its texture closer."
Petroleum for Steam-making.—A successful exhibition was recently made at Pittsburg of a method of using petroleum as fuel on board steamers. In its main features this new method resembles other methods which have been tried with more or less success—air, steam, and oil-spray being injected into a suitable fire-box. The spray is said to be immediately converted into inflammable gas, becoming a pure, bright, powerful flame, free from smoke. To accomplish this result, the inventor resorts to a very simple contrivance, described as follows in the "Journal of the Franklin Institute": A small hole is drilled into the iron front of the fire-box, and into this passes a tube which branches, as it leaves this point, into two pipes. One of these connects with the boiler itself, and the other with a receptacle containing crude oil. At the junction of these pipes there is an aperture for the admission of atmospheric air. Valves of peculiar construction regulate the quantity of steam or oil admitted to the furnace. Our contemporary gives the following account of the experiment made to test the efficacy of this method of employing petroleum in place of coal: "The little steamer Billy Collins was selected by Mr. Campbell for the test. A preliminary blaze of wood under the boiler raised the small quantity of steam necessary to start the burner into operation. The oil-valve was opened a trifle, the steam valve ditto. The petroleum trickled into the feed-pipe, was caught up by the steam, and both plunged into the depths of the fire-box, a mass of many-tongued, roaring, brilliant flame. As the pressure of steam increased, this flame grew in fury and intense heat. The needle of the steam-gauge climbed rapidly up the dial, and in twenty minutes the safety-valve blew off at 120 pounds pressure. . . . To ocean-going steamers this device must prove of extraordinary interest. A tank of oil, situated at a remote end of the ship, would hold fuel sufficient for a double trip, and supplant the great coal-bunkers with their attendant dirt."
What Nordenskjöld has done.—A current misapprehension of the work done by Nordenskjöld (pronounced Nordenshuld), in his recent memorable voyage, is corrected by the "Pall Mall Gazette." He is supposed to have discovered the "Northeast Passage." He has discovered nothing, not even the shore along which he sailed. Every part of his route was known before, and the whole coast-line had been laid down by the expeditions which, for more than three hundred years, have penetrated from the east and west, or, descending the great Siberian rivers, have crept along the European and Asiatic arctic shores in boats or in dog-sleds. What Nordenskjöld has actually done is to have sailed, in one continuous voyage and in one ship, from the Atlantic to the Pacific, and to have made en route a series of scientific collections and observations such as no other explorer in these seas—unless, perhaps, himself in former voyages—had been able to carry away. Professor Nordenskjöld is sanguine that he has proved the feasibility of the northeast passage for ships during most seasons. This the "Pall Mall Gazette" pronounces too hopeful a view, and assuredly a passage which requires over twelve months for its accomplishment can hardly be called "feasible" in any remunerative sense. But one thing is made clear by this voyage, namely, that the great Siberian rivers drive the ice off the coast during several of the late summer and autumn months, and that the Yenisei and Obi may be reached during average years. So confident is the Prussian Government that the products of their Asiatic empire will find their way to European markets by way of the Siberias rivers and the Arctic Sea, that they have already established custom-houses at the entrance to the Yenisei and the Obi.
Effects of Tobacco on the Teeth.—Habitual users of tobacco will draw some comfort from observations made by the author of a paper read before the Odontological Society of London. This writer, Mr. Hepburn, says that the direct action of nicotine on the teeth is decidedly beneficial. The alkalinity of the smoke must necessarily neutralize any acid secretion which may be present in the oral cavity, and the antiseptic property of the nicotine tends to arrest putrefactive changes in carious cavities. The author is inclined to believe that the dark deposit on the teeth of some habitual smokers is largely composed of the carbon of tobacco-smoke. This deposit takes place exactly in those portions where caries is most likely to arise, and on those surfaces of the teeth which escape the ordinary cleansing action of the brush. That tobacco is capable of allaying to some extent the pain of toothache is, he thinks, true—its effect being due not only to its narcotizing power, but also to its direct action on the exposed nerve; and he is inclined to attribute the fact of the comparatively rare occurrence of toothache among sailors in great measure to their habit of chewing.
Distribution of Luminous Power in the Sun's Rays.—With the aid of a new spectrometer based on the optical principle that a light becomes invisible when it is in presence of another light about sixty-four times more brilliant. Professor J. W. Draper has been enabled to prove that all the rays of the sun's light possess the same luminous power. In the prismatic spectrum the luminous intensity is greatest, not in the yellow but in the red; and this effect is due to the action of the prism, which narrows and as it were condenses the colored spaces more and more as we pass toward the red, increasing the intensity of the light as it does that of the heat. But in the grating or diffraction spectrum the luminous intensity is found by Dr. Draper to be equal in all the visible regions, all the colors being simultaneously obliterated by an "extinguishing light," that is, a light about sixty-four times more brilliant. Dr. Draper describes his new spectrometer in the "American Journal of Science and Arts" for July.
The Wild Cattle of Great Britain.—In a work recently published in England is given an account of the origin, history, and present condition of the wild "white cattle" of Great Britain. The supposed primogenitors of these wild cattle were abundant in the Pleistocene age, both in the British Isles and on the neighboring continent, and in later prehistoric times they still existed, as their fossil remains testify. Advancing to historic times, the author. Rev. John Storer, quotes from Herodotus a passage in which mention is made of "large, ferocious, and fleet white bulls" abounding in the country south of Thrace. Poland, Lithuania, and Muscovy were their last strongholds on the Continent of Europe, and they became extinct there in the fifteenth or sixteenth century. But they have still living representatives in England, the Chillingham herd being the most noted. This herd is kept in the, park attached to Chillingham Castle in Northumberland, the residence of Lord Tankerville. The earliest historian on this herd, Mr. Storer says, is Thomas Cully, whose book on "Live Stock," published; in 1786, is pretty well known. The date of the inclosing of the park of course would probably indicate the period when the wild cattle were first confined, but there seems to be no clear evidence on this point. As long ago as the year 1692, however, there is direct proof in Mackenzie's "View of the County of Northumberland," published in 1825, that the herd then existed, for among other curious notes given therein are those of William Taylor, the steward of Chillingham: "May, 1692—Beasts in the parke. My lorde's, 16 white wilde beasts," etc. Since that period they have flourished in fluctuating numbers, never increasing very rapidly, but retaining all their wild characteristics. The herd is now generally kept up to about threescore.
Regarding the herd of wild cattle inclosed in Chartley Castle Park, Staffordshire, the property of Earl Ferrers'a family, accounts alluding to them show of their existence as far back as 1658. They are more massive in character than their congeners of Chillingham, and are not so wild. From what we gather from this most interesting work, the characteristics of the two herds are such as might lead one to infer the descent of the domestic breed of shorthorns from the Chillingham herd, and the old and almost extinct "long-horn" breed from the Chartley stock. It is a remarkable fact in connection with both these herds that the animals individually are built on perfect lines, and their general contour is such that many of our great fat-stock breeders would be glad of such correctly formed frames to work upon.
Of the existing Scotch herds of wild cattle, the only one now found retaining to any great degree its pristine condition is the Hamilton herd in Cadgow Park, Lanarkshire. In 1874 this herd numbered some forty animals.
Other herds have existed, and some half-wild herds still are preserved in a few instances in the British Isles; of all of these Mr. Storer has given most entertaining information.
Circulating Libraries and Contagious Disease.—The question having been raised, at a meeting of the directors of the Chicago Public Library, whether books in circulating libraries may become a means of spreading contagious diseases, a committee was apt pointed to investigate the subject. Letters of inquiry were addressed by this committee to medical and sanitary experts, also to librarians in different parts of the country, and the replies (nineteen in number) are set forth by a member of the committee in a communication to the "Library Journal." None of the writers of the replies could give any fact falling under his own observation tending to show that a contagious disease was ever imparted by a book from a circulating library, and hence the question had to be discussed simply as one of theory. The doctors differed, of course, some of them asserting the risk of contagion to be great, while others held it to be nil. The conclusion reached by the committee is that, "while there may be a possibility that contagious diseases may be transmitted by books of a circulating library, the real danger of such transmission is very small." Nevertheless, they recommend to the directors of the library "to act under the advice of the Commissioner of Health, and adopt such regulations as he had suggested, namely: that he furnish to the library, whenever he thinks proper, a list of the premises infected with contagious diseases, and of their residents; that no books be loaned to such houses until they are reported by the health office to be free from contagious diseases, and that all books returned from such houses during this period be disinfected before they are replaced on the shelves of the library."
Bird-Reasoning.—The first winter after the erection of a telegraph line on the coast of Antrim, Ireland, numbers of starlings migrating from Scotland were found dead or wounded on the roadside, they having, evidently, in their flight in the dusky morning, struck against the wires. Strange to say, during the following and succeeding winters, hardly a death occurred among the starlings on their arrival. The inference drawn from all this by a writer in "Nature" is that "the birds were deeply impressed and understood the cause of the fatal accidents among their fellow travelers, that previous year, and hence carefully avoided the telegraph wires; not only so, but the young birds must also have acquired this knowledge and perpetuated it—a knowledge which they could not have acquired by experience or even by instinct, unless the instinct was really inherited memory derived from the parents whose brains were first impressed by it."
Habits of the Thresher-Shark.—Having received a fine specimen of the fox, or thresher-shark, Mr. Frank Buckland sends to "Land and Water" an account of all he has been able to learn concerning the habits of that animal. Premising that what he says has to be taken with many "grains of salt," we subjoin the main points of his communication. This shark, it appears, is called "the thresher," from the power it has, in company with the sword-fish, to destroy a whale, by jumping into the air and striking the whale with its tail, the sword-fish in the mean time striking the whale from beneath. Mr. Buckland has never seen a thresher hunting mackerel, but believes that this shark "rushes into a shoal of these fish, and lays about right and left with his long tail; when the frightened mackerel are endeavoring to fall into their ranks again, the shark has a good opportunity of seizing them one by one." Of the contests between thresher-sharks and whales he gives the following animated account, on the authority of one Captain Hill, and in that worthy skipper's own words: "The thresher-sharks just do serve out the whales. The sea sometimes is all blood. A whale once got under our vessel—the Hurricane—to get away from these threshers, and when she was there we was afraid to throw a rope overboard, almost to walk about, for fear she should chuck her tail and punch a hole in our vessel. She was full length, in water as clear as gin, right under our bottom, and laid as quiet as a lamb for an hour and a half, and never moved a fin. Where they had been a-threshing of her, the sea was just like blood. I have seen these 'ere threshers fly out of the water as high as the masthead, and down upon the whale while the sword-fish was a pricking of him from underneath. There is always two of 'em—one up and one under; and I think they hunt together, and you can see the poor whale blow in great agitation; and I be bound the pair of them don't leave him till they have had their penn'orth out of him. I don't think they leaves him till they kills him."
Cost of the Proposed Lake in Algeria.—M. Roudaire, the engineer in charge of the preliminary surveys for flooding the Algerian shotts (dried up lake-beds), estimates the cost of the proposed work at not exceeding 20,000,000 francs. It is only necessary to cut through the narrow isthmus separating the head of the Gulf of Gabes from the extremity of the shott El-Djerid, to form the proposed sea. In a letter from M. Roudaire to M. de Lesseps, the advantages which may be expected to result from the creation of this new sea are stated to be "an immense amelioration of the climate of Algeria and Tunis, since the moisture caused by the evaporation from the vast expanse of water will be driven by the prevailing southerly winds over these countries, forming a layer of humid atmosphere which will greatly mitigate the intensity of the solar rays and retard the cooling of the earth by radiation during the night. The proposed sea, too, being navigable for ships of the greatest draught, will also open a new commercial route for the districts lying to the south of the Aures and the Atlas range; while watercourses which from the south, west, and north converge toward the shotts, but which are now dry during the greater part of the year, will again become rivers, as they once undoubtedly were, leading ultimately to the fertilization of vast tracts of now desert land on their banks."
On the Antiquity of Man.—Starting from the opinion generally accepted among geologists, that man was on the earth at the close of the Glacial epoch. Professor B. F. Mudge adduces evidence to prove that the antiquity of man can not be less than 200,000 years. His argument, as given in the "Kansas City Review of Science," is about as follows: After the Glacial epoch geologists fix three distinct epochs, namely the Champlain, the Terrace, and the Delta, all supposed to be of nearly equal length. Now, we have in the Delta of the Mississippi a means of measuring the duration of the third of these epochs. For a distance of about two hundred miles of this delta are seen forest growths of large trees, one over the other, with interspaces of sand. There are ten of these distinct forest-growths, which have begun and ended one after the other. The trees are the bald cypress (Taxodium) of the Southern States, and some of them were over twenty-five feet in diameter. One contained over 5,700 annual rings. In some instances these huge trees have grown over the stumps of others equally large; and such instances occur in all, or nearly all, of the ten forest-beds. This gives to each forest a period of 10,000 years. Ten such periods give 100,000 years, to say nothing of the time covered by the interval between the ending of one forest and the beginning of another—an interval which in most cases was considerable. "Such evidence," writes Professor Mudge, "would be received in any court of law as sound and satisfactory. We do not see how such proof is to be discarded when applied to the antiquity of our race. There is satisfactory evidence that man lived in the Champlain epoch. But the Terrace epoch, or the greater part of it, intervenes between the Champlain and the Delta epochs, thus adding to my 100,000 years. If only as much time is given to both those epochs as to the Delta period, 200,000 years is the total result."
The Immensity of the Stars.—We take from "Le Monde de la Science" the following interesting "Considerations on the Stars," by Professor J. Vinot: "It is known that the stars are true suns, that some of them are larger than our own sun, and that around these enormous centers of heat and light revolve planets on which life certainly exists. Our sun is distant from us 38,000,000 leagues, but these stars are distant at least 500,000 times as far—a distance that in fact is incommensurable and unimaginable for us. Viewed with the unaided eye the stars and the planets look alike, that is, appear to have the same diameter. But, viewed through the telescope, while the planets are seen to possess clearly appreciable diameters, the stars are still only mere luminous points. The most powerful of existing telescopes, that of Melbourne, which magnifies 8,000 times, gives us an image of one of our planets possessing an apparent diameter of several degrees. Jupiter, for instance, which, seen with the naked eye, appears as a star of the first magnitude, with a diameter of 45″ at the most, will in this telescope have its diameter multiplied 8,000 times, and will be seen as if it occupied in the heavens an angle of 100°. Meanwhile a star alongside of Jupiter, and which to the eye is as bright as that planet, will still be a simple dimensionless point. Nevertheless that star is thousands of times more voluminous than the planet! Divide the distance between us and a planet by 8,000, and you have for result a distance relatively very small; but divide by 8,000 the enormous number of leagues which represents the distance of a star, and there still remain a number of leagues too great to permit of the stars being seen by us in a perceptible form. In considering Jupiter, or any of the planets, we are filled with wonder at the thought that this little luminous point might hide not only all the visible stars, but a number 5,000 fold greater—for of stars visible to our eyes there are only about 5,000. All the stars of these many constellations, as the Great Bear, Cassiopeia, Orion, Andromeda, all the stars of the zodiac, even all the stars which are visible only from the earth's southern hemisphere, might be set in one plane, side by side, with no one overlapping another, even without the slightest contact between star and star, and yet they would occupy so small a space that, were it to be multiplied 5,000 fold, that space would be entirely covered by the disk of Jupiter, albeit that disk to us seems to be an inappreciable point."
A Scientific Detective.—One of the most remarkable among recent inventions is the induction-currents balance, briefly described as follows in the "Athenæum": "It consists of two induced currents from separate induction coils, which are so equal that they neutralize each other. They are connected with three elements of a Daniell'a battery, with a small clock and microphone, and a receiving telephone. If a piece of metal is placed in one of the coils, the balance of the currents is disturbed, and the clock is heard to tick; but if another piece of metal, exactly similar, is placed in the opposite coil, the balance is restored, and silence again prevails." From this brief description it will be understood that in this I new instrument the physicist has an exquisitely sensitive test of the molecular constitution of many substances, for it detects the presence of mixtures and alloys, however small the quantity. Hence a scale of qualities may be formed; and if the value of silver be placed at 115° there can be no question that everything that marks 115° must be silver, 52° will be iron, 40° lead, and 10° bismuth; and, further, the instrument is at once affected by magnetism, heat, or strain in the substance under examination, and will indicate even the effect of half a minute's rubbing of a piece of metal between the thumb and finger. The induction-currents balance is a contrivance of Professor Hughes's.
Stained Windows.—The method of constructing stained-glass windows is described as follows in "Chambers's Journal": "The design of the window being determined upon, and the cartoon or full-sized drawing being prepared, a kind of skeleton drawing is made showing only the lines which indicate the shape of each separate piece of glass. It is apparently not generally understood that a window is not one piece of glass, to which are applied the various colors displayed, but a number of small pieces, which are united by grooved lead, which incloses each individual fragment, and that each different color we see is the color of that particular piece of glass, the only painting material employed being the dark-brown pigment used to define the more delicate and minute details. This skeleton or working drawing then passes to the cutting-room, where sheets of glass of every imaginable shade are arranged in racks, each bearing a number, by which a particular tint is known. The drawing being numbered on each separate piece of glass by means of a frame containing small pieces of every shade, and each numbered according to the rack containing the glass of that color, the use of this frame renders unnecessary the tedious process of visiting each rack in search of the particular shade required; the glass is laid bit by bit on the drawing, and each piece is then cut to the required shape by means of a diamond. After the glass is cut, it passes to the painter, who, laying it over the drawing, traces upon it with his brush all the details of features, folds of drapery, foliage, etc., as designed by the artist. But as the action of the weather and the continually varying conditions of the atmosphere would speedily remove every vestige of paint if left in this state, it is necessary to subject the painted glass to the action of heat by placing it for several hours in a kiln, under the influence of which the paint is fused into absolute affinity with the glass, and becomes actually incorporated with its substance. After this burning process, it only remains for the different pieces to be united with the grooved leaden framework which binds the whole together. The places where the leads join are then carefully soldered together, and nothing remains but to thoroughly work over the whole surface with a thick kind of cement, which fills up any interstices between the glass and lead, and renders the whole panel perfectly watertight and weather-proof."
Assimilative Power of Plants.—In a paper read before the Dublin Royal Society, Dr. C. A. Cameron states the result of a preliminary experiment made by him to determine the possibility of substituting for some of the elements in plants other elements of the same atomicity. A sod was taken from a field in which a crop of the so-called artificial grasses (which are chiefly leguminous plants, and not grasses at all) was just peeping over ground. It was placed in a box, and one half of the plants were watered twice a week with a weak solution of potassium selenate. The total quantity of potassium selenate applied to the plants during four weeks amounted to twenty grammes. The result showed that selenic acid, at least when applied in small quantity, does not injure plants. Secondly, it was found that selenic acid had been absorbed by the plants. To determine this point, the plants were partially dried and boiled in strong nitric acid until thoroughly destroyed. The solution was evaporated to dryness, and the residue was treated with dilute hydrochloric acid, which dissolved it nearly completely. The solution was concentrated and raised with a saturated solution of sulphurous acid, whereupon the liquid assumed at once a deep, blood-red color, from the separation of selenium. The plants had been carefully washed before being dried. In concluding his paper, Dr. Cameron writes as follows: "I think this experiment proves that selenic acid is not injurious to plants when used in small quantity, and that the acid is taken up and retained by plants, or at least by certain varieties of plants. The experiment, however, did not prove whether or not there was a partial replacement of sulphur trioxide by selenium trioxide or of sulphur by selenium. Having lately become possessed of large quantities of selenium compounds, I propose to grow plants in soil or water free from sulphur in any form, but supplied with potassium and ammonia selenates. Should the results of this proposed experiment prove interesting, I shall do myself the honor of submitting them to the society."
Honey-making in the United States.—The annual production of honey in this country is estimated at about 35,000,000 pounds, and the business of bee-keeping is being rapidly systematized. One firm of wholesale grocers in New York keeps as many as 12,000 swarms; other keepers have often from 3,500 to 5,000 swarms. Arrangements are made with farmers and owners of orchards to allow an apiary of a certain number of swarms to be placed in their grounds. At the distance of three or four miles another apiary is placed with another farmer, and so on. For this accommodation the bee-keepers pay either in money or in shares. It is estimated that on an average an acre will support twenty-five swarms, yielding fifty pounds of honey each. The apiaries are cared for by men in the employ of the bee-owners. Many ingenious contrivances have been introduced for the purpose of saving the labor of the bees and the keepers. About ten years ago a German suggested that thin, corrugated sheets of wax, which he called "artificial tablets," should be provided for the bees to make their comb from. These, however, did not come into general use; but a few years ago Mr. W. M. Hoge effected an improvement by starting the side-walls of the cells. When these "foundations," as they are called, were presented to the bees, the intelligent little creatures at once took advantage of them, and extended the side-walls so as to form the regular hexagonal cell. The machine by which the impression is made on both sides of the wax is very simple, and somewhat resembles a clothes-wringing machine, only the iron rollers are studded with little hexagonal-headed pins just the size of the section of a cell, so that, when the thin sheet of wax is pressed up between the pegs to the height of about one sixteenth of an inch, it offers a substance for the construction of the cell-walls. Another remarkable adaptation of machinery is afforded by the use of a rotating frame, which causes the cells of the comb placed in it to be emptied by centrifugal force. The empty, uninjured comb is afterward replaced in the hive, and again used by the bees. As about three fourths of the time of the bees, it has been computed, is taken up in the construction of the comb, it will be seen that by these contrivances a great saving of bee-labor is effected.
Brain-Texture and Mental Make-up.—The members of the Paris Anthropological Society were not a little surprised by the tenor of a report made by M. Thulié upon the appearance of the brain and cranium of M. Asseline, one of their fellows, lately deceased, at the age of forty-nine. M. Asseline belonged to a "society for mutual autopsy," and the examination of his brain was made by his bereaved cosocietaires, who were prepared to find in it all the commonly received external indications of a highly refined and intellectual nature. He had been a republican and a materialist; possessed enormous capacity for work, great faculty of mental assimilation, and an extraordinarily retentive memory; had a gentle, kindly disposition, keen susceptibilities, refined taste, and subtile wit. As a writer he had always displayed great learning, unusual force of style, and elegance of diction; and in his intercourse with others' he had been unassuming, sensitive, and even timid. But "the autopsy showed," says "Nature," "such coarseness and thickness of the convolutions that M. Broca presumed them to be characteristic of an inferior brain. The fossæ or depressions regarded by Gratiolet as of a simian character, and as a sign of cerebral inferiority, which are often found in women, and in some men of undoubted intellectual inferiority, were very much marked, especially on the left parieto-occipital. But the cranial bones were at some points so thin as to be translucent; the cerebral depressions were deeply marked, the frontal suture was not wholly ossified, a decided degree of asymmetry was manifested in the greater prominence of the right frontal, while, moreover, the brain weighed 1,468 grammes—i. e., about sixty grains above the average given by M. Broca for M. Asseline's age."