ACTION OF ORGANIC ACIDS ON MINERALS.
DR. H. C. BOLTON of the New York School of Mines has made the interesting discovery that minerals may be decomposed by boiling with organic acids, just as they are by treatment with the strong mineral acids. He has tried the action of such acids as citric, tartaric, oxalic, acetic, malic, and other acids, on finely powdered carbonates, silicates, sulphides, and other cla.s.ses of mineral. All the carbonates examined (fourteen in number) dissolved with effervescence, sulphides were decomposed with evolution of sulphuretted hydrogen, and silicates with formation of gelatinous silica. This important discovery will greatly add to the resources of the mineralogist, who is compelled to do much of his work in the field. Hitherto he has been debarred from using the mineral acids (the action of which sometimes forms a decisive test) by the impossibility of carrying them in the pocket or wallet without danger. The organic acids are solid, and can be conveniently stowed away. Their action, however, is not so decided as that of the mineral acids, but this is not always a defect, but offers additional means of determination. For example, all the specimens of bornite and pyrrhot.i.te examined yielded sulphuretted hydrogen with tartaric, citric, and oxalic acids, but chalcopyrite and pyrite do not. On the other hand, the use of the organic acids may give rise in some cases to the formation of nitric acid, which in its nascent condition will afford a very powerful agent of decomposition. Thus all the sulphides examined (seventeen), with the exception of molybdenite and cinnabar, were quickly attacked by citric or tartaric acid, to which a little pota.s.sium nitrate had been added. Pota.s.sium chlorate produces a similar though slower action. These examples are sufficient to show that Dr.
Bolton has found a promising field of inquiry, and, singular to say, considering the attention which the action of organic acids has received, it is a field believed to be entirely new. He is continuing his researches.
SCIENTIFIC ORCHESTRATION.
Prof. Mayer has turned his valuable researches in acoustical science to aesthetic uses, and criticises the present mode of arranging orchestras, the defects of which he proves by experiment. He took an old silver watch, beating four times a second, and caused it to gain thirty seconds per hour, so that every two minutes its tick coincided with the tick of an ordinary spring balance American clock, also making four beats the second. The latter was placed several feet, and the watch two feet, from the ear. In this position the ticks of the watch were lost for _nine seconds_, about the time of coincidence. The tick of the watch disappeared, "with a sharp _chirp_, like a cricket"s, and reappears with a sound like that made by a boy"s marble falling upon others in his pocket." This experiment shows most effectively that one sonorous impression may overcome and obliterate another, but to do so it must be more intense and of lower pitch. If of higher pitch, it cannot neutralize the other sound, however much the first may exceed the latter in intensity. This discovery, Prof. Mayer thinks, is, "next after the demonstration of the fact that the ear is capable of a.n.a.lyzing compound musical sounds into their const.i.tuent or partial simple tones, the most important addition yet made to our knowledge of hearing." High sounds cannot obliterate low ones, but, on the contrary, the sensation of each partial tone of which compound musical sounds is formed is diminished by all the tones below it in pitch. These discoveries he applies to orchestration as follows: "In a large orchestra I have repeatedly witnessed the complete obliteration of all sounds from violins by the deeper and more intense sounds of the wind instruments, the double ba.s.ses alone holding their own. I have also observed the sounds of the clarinets lose their peculiar quality of tone, and consequent charm, from the same cause. No doubt the conductor of the orchestra heard all his violins ranged as they always are, close around him, and did not perceive that his clarinets had lost that quality of tone on which _the composer_ had relied for producing a special character of expression. The function of the conductor seems to be threefold: First, to regulate and fix the time. Second, to regulate the intensity of the sounds produced by individual instruments, for the purpose of expression. Third, to give the proper quality of tone or _feeling_ to the whole sound of his orchestra, considered as a single instrument, by regulating the _relative intensities_ of sounds produced by the various cla.s.ses of instruments employed. Now this third function, the regulation of relative intensities, has. .h.i.therto been discharged through the judgment of the ears of a conductor, who is placed in the most disadvantageous position for judging by his ears. Surely he is not conducting for his own personal gratification, but for the gratification of his audience, whose ears stand in very different relations from his own in respect to their distance from the various instruments in action. Is it not time that he should pay more attention to his third function, and place himself in the position occupied by an average hearer? This position would be elevated, and somewhere in the midst of the audience. That the position at present occupied by the conductor of an orchestra has often allowed him to deprive his audience of some of the most delicate and touching qualities of orchestral and concerted vocal music, I have no doubt, and I firmly believe that when he changes his position in the manner now proposed, the audience will have some of that enjoyment which he has too long kept to himself." These views were verified by Prof. Mayer visiting different parts of the house during a public performance, and observing the different effects of the music. It is not to be supposed that a satisfactory change can be made at once. A quant.i.tative a.n.a.lysis of the compound tones of all musical instruments must be made. On this work he is now engaged. One noteworthy result of his researches is the opinion that orchestral instruments should be made on different principles from those used in solos. The reason for this is, that certain over tones should predominate in orchestral instruments in order to give them their due expression in the midst of graver sounds.
These exaggerated peculiarities will unfit them to be played alone. If the learned Professor"s views are carried out, a theatre or opera manager will be obliged to own the instruments of his orchestra, and perhaps to have different sets for different musical works!
THE NITROGEN OF PLANTS.
The direct source of the nitrogen contained in plants is an unsolved mystery, though the ultimate source of much of it must be the atmosphere. A wheat crop gave on unmanured land from 15.9 to 25.2 pounds of nitrogen, per acre, yearly, but the amount found in the rainwater of the same district was only from 6.23 to 8.58 pounds per acre. Singular to say, the use of a fertilizer, called a "complex mineral manure" in the reports, added only about two pounds of nitrogen per acre. But the case is altered when pota.s.sic manure is used, and especially when applied to land bearing beans. Such a crop gains 13-1/2 pounds of nitrogen by the addition of saltpetre, or 28 per cent. A similar result was obtained with clover--a leguminous crop. A pota.s.sic fertilizer increased the yield of nitrogen one-third. One of the anomalies observed in the study of plant growth is that a good crop instead of exhausting the soil seems to improve it. The better the crop, and the more nitrogen removed, the better will the succeeding crop be. Thus clover removes a much larger amount of nitrogen than wheat, the quant.i.ty being on unmanured land, say 30.5 pounds per acre for clover and 20.7 pounds for wheat, and yet the wheat crop is improved if clover is occasionally interpolated or a fair rotation of crops kept up. In 1874 barley succeeding barley gave 39.1 pounds of nitrogen, while barley following clover gave 69.4 pounds of nitrogen withdrawn from an acre of soil. These amounts take no account of the nitrogen carried off by the drainage of the soil, which a.n.a.lysis of drainwater proves to be considerable. The source of all this nitrogen is undoubtedly the atmosphere, but the mode of conveying it into the soil is unknown.
IMPORTANT PREHISTORIC DISCOVERIES.
Few persons are aware of the wealth of what are called "prehistoric"
remains. The finding of an isolated skeleton, in a cave, with stalagmite completely covering it, is accepted as an occurrence that is not very remarkable. However ancient it may be, the preservation of the bones is exceptional. But a late discovery in France, near Hastiere-sur-Meuse, is of much more importance. No less than fifteen burial caverns were found, and from the five that have been explored no less than fifty-five human skeletons have been taken, among which are thirty-five well-preserved skulls.
In addition to these "finds" the plateaux yielded sixteen dwelling places of the old inhabitants from which have been taken a quant.i.ty of stone implements. These show the age of the skeletons to be that of the polished, or "new" stone period. The prospect of being able to restore the men who lived before the earliest recorded dates is now very good.
Some hundreds of their skeletons, with a valuable series of skulls and enormous collections of their handiworks, are now in the museums of the world.
Some of the more remarkable of these discoveries have been alluded to at different times in this Miscellany. One of the latest and most interesting consists of some pointed sticks, found in a Swiss coal bed, the pointing having been done by hand. It may be thought difficult to establish so remarkable a fact in a ma.s.s of coal in which the rods have been pressed flat and perfectly carbonized. But a microscopic examination of one of these pieces shows that the fibres of the wood run in two different directions, the two systems meeting at an angle.
One of the sticks has had its end shaved down, the cut surface being then applied to the other, and some substance, probably bark, being wound around the joint. The marks of this wrapping are perfectly distinct, and in one case the wrapping itself remains. As the bark used for this purpose was different from the natural bark of the rods, the microscope is now able to distinguish between the two, though both are turned to coal. Descriptions and ill.u.s.trations of these interesting relics are published in the "Primeval World of Switzerland," by the celebrated Professor Heer. There is no doubt they formed part of some basket work. Their age is still doubtful, but must be very great.
THE PHYLLOXERA CONQUERED.
The investigation inst.i.tuted by the French Academy of Sciences into the best means of destroying the phylloxera, or grapevine pest, has ended in the conclusion that the sulpho-carbonates are a complete antidote to these destructive insects. This result has already been announced in this Miscellany, and it only remains to explain the action of these salts. Under the influence of carbonic acid, which is always present in soils containing organic substances, they decompose. A carbonate is formed, and sulphuretted hydrogen and bisulphide of carbon are evolved.
Both of these are deadly poisons to the phylloxera as well as to man.
To complete the fitness of these salts to agricultural uses, the sulpho-carbonate of pota.s.sium has an excellent effect upon the vines, potash being one of the most valued const.i.tuents of manures. Success in using the antidote depends upon bringing it in contact with every part of the root-system of the plant. This can be done by dissolving the salt, but it is better to mix it with half its weight of lime and sprinkle it on the ground at the beginning of the rainy season, which in France lasts from October to March. M. Mouillefert, who examined this subject under direction of the Academy, reports that as an antidote the sulpho-carbonates are a proved success, and nothing now remains but to educate the vine growers to their proper use. This subject has peculiar interest to Americans, for the phylloxera is our evil gift to France. It is matter of common observation, both in animal and vegetable physiology, that one race or species may live in comfort with an enemy--be it a disease or a parasite--which is destructive to other species. The American vineyards are by no means free from the phylloxera. On the contrary, they are full of this insect, but the vines do not lose their hardiness in consequence. They flourish in spite of their enemy.
THE SUN"S HEAT.
Prof. Langley of the Allegheny observatory has made a direct comparison between the heat of the sun and that of the flame in the mouth of a Bessemer steel convertor. Estimates of the sun"s temperature probably vary among themselves more than any other attempts at scientific knowledge, ranging from 10,000,000 down to 1,500 deg. We have already published in this Miscellany some late French determinations which place it below 2,000 deg. C. Prof. Langley"s choice of a standard is excellent. The flame of the Bessemer convertor results from the burning of carbon, silicon, iron, and manganese within the vessels, the result of using this once novel fuel being a heat so great that the most refractory iron or steel is melted to thin fluidity and so much excess of heat imparted, that the ma.s.s will remain fluid, without further heat, a considerable time. The temperature of the flame is not known, though 4,000 or 5,000 deg. Fahr. has been suggested as an approximation.
This does not vitiate Prof. Langley"s experiment, for he used it merely as one of the most powerful artificial sources of light obtainable. His method was to compare its light with that of the sun by an arrangement that resembled a camera obscura, the light from the sun and the flame being repeatedly superposed upon each other. The arrangement worked admirably, and the observer was able to note the spots on the sun. He found that the intensely hot flame was like a dark spot compared to the sun"s light and that the latter must be at least 2,168 times hotter than the flame. This carries the result in favor of the largest estimates. The flame of the convertor is not so hot as the melted steel from which it comes, but it offers better opportunities for observation. The steel itself as it was poured from the convertor was found to be not more than one-sixty-fourth as hot as the sun.
DEAF MUTES IN POLAND.
Mr. George Darwin has brought forward statistics to prove that the intermarriage of near relations does not have the unfavorable effect upon offspring which is commonly supposed. But the director of the Warsaw Inst.i.tute for Deaf Mutes and the Blind combats this theory, and says that the registers kept at that and similar inst.i.tutions support the popular opinion. The system of instruction at this asylum is very perfect. Mimic language being almost totally prohibited, the pupils are taught to understand the motion of the lips and to speak more or less distinctly; and after a four years" residence in the Inst.i.tute, they generally attain in both a high degree of perfection. With great judgment the managers have made the technical instruction at the school of the best kind, so that the pupils readily find situations on leaving, and indeed there are never enough to fill all the situations offered. This appears to be the true method with students who would otherwise find themselves at a disadvantage with more favored compet.i.tors.
THE COMPa.s.s PLANT.
The well-known dispute as to the "compa.s.s plant" has recently been settled by Mr. Meehan in a manner which recalls the opinions of judicial officers who deal with other than scientific questions. One party of observers say that this plant always points its leaves north and south, the leaf standing edgewise to the earth and the two sides facing to the east and west. This plant is found on the prairies and plains, and is known scientifically as _silphium lacinatum_, popularly as pilot weed, rosin weed, and turpentine weed. It stands from three to six feet high, and the trappers and Indians are said to find their way in dark nights by feeling its leaves. These a.s.sertions of polarity are denied by the other party. Mr. Meehan now says that both are right.
When the leaves are young and small the pointing to the north is unmistakable, but when they become larger, are beaten down by rains, and weighted with sand and dew, they are not able to recover their lost bearings.
BALLOONS IN METEOROLOGY.
Balloon ascensions are quietly but frequently used by scientific men for the purpose of studying the upper parts of the atmosphere. Russian savants have lately paid especial attention to this work, but have been prevented from extending their examinations to any great height. Prof.
Mendeleef of St. Petersburg now undertakes to accomplish this also, and devotes the profits of two books published by him to the construction of a balloon. This is to have a capacity of two or three thousand cubic yards, and will be filled by means arranged by him. France also pursues this path of investigation with great vigor. Count Bathyani recently took up a radiometer to a height of about a mile. At the earth it made in the shade thirty-five revolutions per minute. At the height of 5,000 feet it made sixty-four revolutions, also in the shade. In the sun, 2,300 feet above the earth, it made fifty-four revolutions. Count Bathyani also took up an ethereal apparatus for the purpose of condensing water vapor at various heights, in order to collect the microscopic particles floating in the air. This line of investigation will be continued by means of an apparatus filled with methylic ether.
This will give a temperature of -20 deg. C., or -15 deg. Fahr. The moisture will condense as ice which will be sc.r.a.ped off the vessels.
All the solid particles floating in the immediate neighborhood of the apparatus will also be obtained.
THE LEAD PRODUCT.
The mining of lead is a business in which Americans are successfully using the remarkable resources of this country. In 1866 the amount made here was only 14,342 tons, while we imported 23,330 tons. In fact the importation has exceeded the home product ever since 1850 with the exception of one year--1860. This improper "balance of trade" was due to the system and intelligence with which foreign smelting works are conducted, and the ignorance which prevailed in our own country where the mining resources are really superior to those of Europe. But this state of things has changed with the foundation of mining schools and the spread of mining knowledge in this country. In 1873 the "balance"
turned the other way. The importations have been since then 22,114, 17,674, 7,305, and 4,685 tons; while the home product shows a rise corresponding closely to this falling off, being for the same years, 37,983, 46,500, 53,250, 57,210 tons. In fact we export as much as we import, for the 4,300 tons of pig lead imported is balanced by the quant.i.ty sent back to Europe in the form of bullets. This change in the business is traceable to the fact that refining has been found to pay in America, and our lead is thus in request by the white paint makers.
For years our product lay under a stigma, and it was said that it was not suited to the manufacture of the best lead. This evident error has been corrected; the refined virgin lead of Missouri and Illinois makes the best white lead, and the mining of the metal is not likely to suffer from so many causes of depression again. The Territories are now large producers, the five princ.i.p.al sources of supply being in 1876--
Tons.