ASSERTED ARTIFICIAL PRODUCTION OF THE DIAMOND. whatever of the claim of Mr. Mactear, of the St. Rollox Works, Glasgow, to the artificial production of the diamond. My name, however, was already in several newspapers as that of a person in whose hands the asserted diamonds had been placed for a decision as to their true nature. Ultimately a small watch-glass with a few microscopic crystalline particles came into my hands for this purpose from Mr. Warington Smyth, and subsequently a supply came to me direct from Mr. Mactear. I shall proceed to state the results I have obtained from the examination of these. Out of the first supply I selected by far the largest particle, one about the onefiftieth of an inch in length, and it may be that I wasted some time in experimenting on this particle, as it might not have been an authentic example of the "manufactured diamond," since it differed in some respects from the specimens I have since received direct from Mr. Mactear. 66 319 erfully in the manner of a birefringent crystal. It seemed even in one or two of them that when they lay on their broadest surface (it can scarcely be called a crystal-face") a principal section of the crystal was just slightly inclined to a flattish side of it in a manner that suggested its not being a crystal of any of the orthosymmetrical systems. Be that as it may, it is not a diamond. Finally, I took two of these microscopic particles and exposed them to the intense heat of a table blow-pipe on a bit of platinum foil. They resisted this attempt to burn them. Then, for comparison, they were placed in contact with two little particles of diamond dust exceeding them in size, and the experiment was repeated. The result was that the diamond particles glowed and disappeared, while the little particle from Glasgow was as obstinate and as unacted on as before. I had previously treated the specimen I have alluded to as the first on which I experimented by making a similar attempt in a hard glass tube in a stream of oxygen, and the result was the same. Hence I conclude that the substance supposed to be artificially-formed diamond is not diamond and is not carbon, and I feel as confident in the results thus obtained from a few infinitesimal particles that can barely be measured and could only be weighed by an assay balance of the most refined delicacy, as if the experiments had been performed on crystals of appre The diamond excels all substances in hardness. Its crystals belong to the cubic system, and should not, therefore, present the property of doubly refracting light. Frequently, however, from the influence of strains within the crystal due to inclosed gas bubbles, or other causes, diamonds are not entirely without action on a ray of polarized light sent through them. Finally, the diamond is pure carbon, and, as such, burns entirely away when heated to a sufficiently high temperature in the air, and more vividly sociable size. burns, or rather glows away, when heated in oxygen gas. The specimens I had to experiment upon were too light to possess appreciable weight, too small even to see unless by very good eyesight or with a lens, yet were, nevertheless, sufficiently large to answer the three questions suggested by the above properties. A few grains of the dust, for such the substance must be termed, were placed between a plate of topaz- a cleavageface with its fine natural polish and a polished surface of sapphire, and the two surfaces were carefully "worked" over each other with a view to the production of lines of abrasion from the particles between them. There was no abrasion. Ultimately the particles became bruised into a powder but without scratching even the topaz. They are not diamond.` Secondly, some particles more crystalline in appearance than the rest were mounted on a glass microscope slide and examined in the microscope with polarized light. They acted each and all pow Not content with merely proving what these crystalline particles are not, I made an experiment to determine something about what they are. Heated on platinum foil several times with ammonium fluoride, they became visibly more minute, and a slight reddish white incrustation was seen on the foil. At the suggestion of Dr. Flight, assistant in this department, a master in the craft of the chemical analyst, these little particles were left for the night in hydrofluoric acid in a platinum capsule. This morning they have disappeared, having become dissolved in the acid. I have, therefore, no hesitation in declaring Mr. Mactear's "diamonds" not only not to be diamonds at all, but to consist of some crystallized silicate, possibly one resembling an augite, though it would be very rash to assert anything beyond the fact that they consist of a compound of silica, and possibly of more than one such compound. The problem of the permutation of carbon from its ordinary opaque black condi tion into that in which it occurs in nature, | its sublimation in the form of crystals, or as the limpid crystal of diamond, is still its cooling into crystal diamond from the unsolved. That it will be solved no liquid state, is one involving a combinascientific mind can doubt, though the tion of high temperature and high presconditions necessary may prove to be sure present in the depths of the earth's very difficult to fulfil. It is possible that crust, but very difficult to establish in a carbon, like metallic arsenic, passes di- laboratory experiment. rectly into the condition of vapor from NEVIL STORY-MASKELYNE. that of a solid, and that the condition for MODERN EXPLOSIVES.— Old-fashioned people, whose acquaintance with explosives is confined to a knowledge of gunpowder, have been startled by the appearance of late years of a whole army of new-fangled compounds, the names of which are alone sufficient to puzzle any ordinarily constituted mind. Guncotton, nitro-glycerine, dynamite, litho-fracteur, cotton-powder, tonite, glonoine, dualine, saxafragine, mataziette, glyoxiline, and blasting gelatine are among the names by which these new explosives have been brought forward; and to those little versed in such matters it seems well-nigh hopeless to attempt to keep pace in one's knowledge with a class of compounds that every day grows more and more extensive. We may know what gun-cotton is, and have a suspicion how nitro-glycerine is made, but beyond this most people do not go. It appears useless, indeed, to follow the science of explosives under such circumstances, for no sooner can you become acquainted with the nature and qualities of one than the morrow sees other and more curiously-named compounds spring into being. Gun-cotton is a nitro-compound in a solid form; nitro-glycerine is a nitro-compound in a liquid form, and of but these two the whole series I have mentioned consists. Cotton-powder is gun-cotton reduced to a fine state of division; and tonite is the same, with the admixture of a nitrate or similar body; dynamite is clay or other earth saturated with nitro-glycerine; and lithofracteur, roughly speaking, is the same thing, with a little saltpetre and sulphur added. Dualine is small granules of gun-cotton soaked in nitro-glycerine; and blasting gelatine is not gelatine at all, but nitro-glycerine in which gun-cotton has been dissolved so as to form a sort of jelly. There is a yet more novel explosive compound - the newest of all-which consists of adding to this "gelatine" a further quantity of gun-cotton, making a sort of dough, whose destructive properties seem to combine those of gun-cotton and nitro-glycerine. Glonoine is simply another name for nitro-glycerine; and saxafragine and mataziette are aliases for dynamite. So that we really come down to two bodies, namely, gun-cotton and nitro-glycerine; and these may, as I have said, be regarded as the same, with the exception "that one is solid and the other liquid. Science for All. THE CUCKOO. -The reason for the parasitic habits of the cuckoo is hard to discover, but it appears probable that the number of males greatly exceeds that of the females, and one observer has calculated that the preponderance of the former sex over the latter is so great as twenty-five to one. This would seem to be too large an estimate, but the proportion is probably about five males to one female. The latter may not only be distinguished by its somewhat darker plumage, and a certain red color on the chest (which is more apparent when the bird is alive), but has a somewhat different note from that of her mate, and calls cuckoo in a much sharper and less emphasized way than the male bird. Thus, if the call of the female be represented by the syllables cuck-00, the responsive utterance of the male would be coo-coo. The female has also another call-note, which may be described as "whittling," and is well expressed by Brehm as kwikwikwik, the sound of which is quite sufficient to set all the male cuckoos within hearing cuckoo-ing with might and main. Thus it happened to the writer, on a still, quiet evening in spring a few years ago, to be fishing beneath a large elm-tree on the river Thames, when a female cuckoo flew into the topmost boughs and uttered her peculiar note. From four different points of the compass she was answered by male birds, who one and all directed their flight toward the tree where she was perched. A tremendous scrimmage ensued, and apparently a fight took place, but being suddenly alarmed, they all took flight in different directions. It is certain that during the breeding season the cuckoo is a very passionate bird, and loves to call until, from sheer hoarseness, he is obliged to stop; sometimes his cry comes from the middle of a thicklywooded tree, at other times he will sit on a bare dead branch, or swing in the breeze from the top of a fir-tree. The female bird is more retiring and keeps nearer the ground, so that it is possible to shoot her by hiding behind a tree as she hunts after insects near one of their favorite haunts. The same plurality of males has been observed by the author during the spring at Avington Park, in Hampshire; and on one occasion, when the female was shot, the note of the males was scarcely heard again, as if they had disappeared from the vicinity. Cassell's Natural History. For EIGHT DOLLARS, remitted directly to the Publishers, the LIVING AGE will be punctually forwarded for a year, free of postage. An extra copy of THE LIVING AGE is sent gratis to any one getting up a club of Five New Subscribers. Remittances should be made by bank draft or check, or by post-office money-order, if possible. If neither of these can be procured, the money should be sent in a registered letter. All postmasters are obliged to register letters when requested to do so. Drafts, checks and money-orders should be made payable to the order of LITTELL & Co. Single Numbers of THE LIVING AGE, 18 cents. A GOOD OLD MAN. "Children, you will soon lay me in the ground. Then you are to be cheerful, and drink some of this wine; for I have lived a joyful life before God all my days." (Life of Ernst Maurice Arndt. London. 1879. P. 38.) THE old man sate beside the fire, His years fourscore and two, His children's children round him stood, I shall never climb thy peak, Great white Alp, that cannot speak Of the centuries that float over thee like Dumb of all God's secret things dreams, Sealed to beggars and to kings; Yet I sit in a world of sight, Color, beauty, sound, and light, While at every step, meseems, Small sweet joys spring up, like gleams Of blue gentian. And he called for a glass, and placed on the I shall not live o'er again 'board "Your hands must lay my head. This glass I fill with thanks to Him Who made my cup through fourscore years "There might be clouds; but they have passed; For this I surely knew, Behind the clouds there dwelt a sun "There might be frets; but not with me "Then fill the sparkling glass, brave boys, "And keep a stout heart in your breast, And march right forward without fear, "And when you lay my head, brave boys, Good Words. JOHN STUART BLACKIE. BLUE GENTIAN: A THOUGHT. BY THE AUTHOR OF "JOHN HALIFAX, GEN- I SHALL never be a child, Nor a free-footed maiden any more, This strange life, half bliss, half pain; I shall sleep till Thou call'st me to arise, Ah! when faith grows dim and dies, And blue gentian. Good Words. Libanius, one of the most eminent of the later pagans, was the guide, philosopher, and friend of the emperor Julian. He was therefore in, yet not ef, a more or less Christian society, whose morality he practised, but whose faith and hope he did not share. Some readers will feel an historical, if not a personal, interest in reflecting for a moment on the dreary sense of isolation and on the restless murmurings akin to those contained in this "Lament," to which such a man with such surroundings was assuredly not a stranger. From The Modern Review. of the doctrine of the "Correlation of the Physical Forces" by Professor (now Sir William) Grove, and the researches of Mr. Joule on the "Mechanical Equiv alent of Heat," seemed to me to bring this view of dynamical causation into yet greater importance; by showing that what is true of that form of force which is now distinguished as molar) motion, may be legitimately extended to those other forms which are manifested in the molecular changes that express them SOME thirty years ago, I enjoyed opportunities of discussing with John Stuart Mill (whose younger brother had been for twelve months an inmate of my house) many questions of philosophy in which we both felt the deepest interest. Among these was the doctrine of causation set produces or resists mechanical (or what forth in his recently-published "System of Logic: ""We may define the cause of a phenomenon to be the antecedent, or the concurrence of antecedents, on which it is invariably and unconditionally selves in chemical action, or impress us consequent." I pointed out to my friend that when this assemblage of conditions is analyzed, it is uniformly found resolvable into two categories, which may be distinguished as the dynamical and the material; the former supplying the force or power to which the change must be attributed, whilst the latter affords the conditions under which that power is exerted. Thus, I urged, when a man falls from a ladder because (as is commonly said) of the breaking of the rung on which his foot was resting, the real or dynamical cause of his fall is the force of gravity, or attraction of the earth, which pulls him to the ground when his foot is no longer supported; the loss of support being only the material condition or collocation, which allowed the force previously acting as pressure on the rung, to produce the downward motion of the man who stood upon it. To this Mr. Mill's reply was, that the distinction is one of metaphysics, not of logic. I ventured, however, to press on him that to whichever department of philosophy this point is to be referred, it is one of fundamental importance; that, assuming experience as the basis of our knowledge, we recognize the downward tendency of every body heavier than air, by our sense of muscular tension in lifting it from the ground, or in resisting its descent towards the earth; and that our cognition of force through this form of sensation, being thus quite as immediate and direct as our cognition of motion through the visual sense, ought to be equally taken account of. with the sensations of heat, light, etc. Partaking of the general ignorance at that time prevalent in this country of the doctrine of "conservation of energy," already promulgated in Germany by Mayer and Helmholtz, I myself endeavored to carry Professor Grove's principle into the domain of biology; by showing that what physiologists had been accustomed to call vital force, may be regarded as having the same correlation" with the various forms of physical force as they have with each other. And in the introduction to the fourth edition of my "Human Physiology" (published in 1853), I thus explicitly defined my position: 66 When this assemblage of antecedents is analyzed, it is uniformly found that they may be resolved into two categories, which may be distinguished as the dynamical and the mate rial, the former supplying the force or power to which the change must be attributed, whilst the latter affords the conditions under which that power is exerted. Thus in a steam-engine we see the dynamical agency of heat made to produce mechanical power by the mode in which it is applied: first, to impart a mutual repulsion to the particles of water; and then, by means of that mutual repulsion, to give motion to the various solid parts of which the machine is composed. And thus, if asked what is the cause of the movement of the steam-engine, we distinguish in our reply between the dynamical condition supplied by the heat, and the material condition (or assemblage of conditions) afforded by the "collocation" of the boiler, cylinder, piston, valves, etc. . . . In like manner, if we inquire into the cause of the germination of a seed-which has been On the Mutual Relations of the Vital and Physical The promulgation, about the same time, Forces, in Philos. Transact. 1850. |