NEWS the specific gravity of their own. If it be true that it contains 20 per cent of the vapour of liquid hydrocarbons, it is difficult to understand how the sp. gr. can be much less than that of common air. Hexane, for instance, C6H14, one of the largest constituents of petroleum spirit, has, at standard pressure and temperature, a vapour density very nearly three times that of the atmosphere. The new process claims to effect a great saving in regard to expense. One ton of coal by the old process yields, in round numbers, 10,000 cubic feet of gas; whereas by the new, one ton of coke should yield from 130,000 to 150,000 cubic feet, or possibly even more. The result is stated in the prospectus to be that the labour of twentynine out of every thirty men will be saved. In another part of the same prospectus, we are, however, told that the saving of labour will be "to the extent of 50 per cent," so that there appears some ambiguity in the matter. Messrs. Quick and Son, the engineers, report, as the result of their experiments and calculations, that " gas of 16 candle-power may be manufactured at a cost of is. 7d. per thousand cubic feet." Such a consummation is devoutly to be wished, but its realisation must obviously depend upon a somewhat complex set of conditions. The managers of the undertaking do not hope, we understand, to get their processes adopted in large English towns, for the present at any rate. Probably they are wise, for if they did they would at once be met with the difficulty, Where is the necessary coke to come from if the old mode of gas-making be abandoned? Charcoal, or even wood, would hardly be proposed as a substitute in this country. In many foreign countries the case is very different, and it certainly appears possible, or even perhaps probable, that in places where wood is cheap and coal very dear, this process, or some slight modification of it, may be adopted with advantage. One of our contemporaries, animadverting somewhat severely upon the new process, exclaims against the idea of introducing so deadly a poison as carbonic oxide into our houses. The point is one of great importance. It is true that ordinary coal-gas contains this poison to the extent of some 5 or 6 per cent. It is also true that carbonic oxide is completely converted into the comparatively harmless carbonic acid when burnt, but there is some difference after all between 5 or 6 per cent and 29, and the risk of an escape of gas would be materially increased by the presence in it of so large a quantity of such a deadly ingredient. Here, again, we require more information, but we must admit that we hardly think it likely that the terrific results dreaded by our contemporary would be verified even if the new gas were introduced. Surely it is an exaggeration to say that "an escape of this gas, such as takes place in many houses every day with coal-gas, would be certain death to every one of the inhabitants." In conclusion, we will remark that, although it has been our duty to present to our readers the chief doubts that beset us in regard to the new scheme, we are far from thinking it absurd or unworthy of trial; on the contrary; we would fain hope that under certain circumstances it may prove a valuable addition to our means of comfort. sorb litharge precisely as bone-ash does in cupellation ; but it acts at the same time as a kind of shield to protect the copper from oxidation. 59. Berzelius employed B as a test of phosphoric acid in phosphates by the insertion through the mass of a piece of pure iron wire, which is corroded and fused if the phosphoric acid exists over 5 per cent; but this reaction, to be effectual, presupposes the perfect solution of the substance containing the phosphate in B, which, as will be seen, can be effected with very few oxides indeed. 60. In fact it is precisely the insolubility of almost all substances but the alkalies in boric acid which gives it the extraordinary value it undoubtedly possesses as an agent of separation; and the following few examples will not only clearly demonstrate this fact to the impartial chemist, but show him that the fact itself has been utterly passed over by writers on the subject hitherto, and that the real analytical value of B, therefore, has remained unknown. Oxides of Cerium, Didymium, and Lanthanum. 61. If a good specimen of the mineral "cerite" be powdered and applied to a bead of B in an O. P., the following phenomenon results. The substance appears to separate into three distinct parts:-(1) red-brown and resinous-looking round spots appear near, but not on the surface; (2) other round spots, more bulky or puffed out, nearer the middle of the bead, of a pale buff colour; (3) a slight milky turbidity through the bead, as though a finely divided precipitate were suspended throughout the If what is sold or made by the chemists as whole mass. 62. These round spots are observed to be round through a lens when viewed in every direction; they are therefore sphericles or globules. After considerably long treatment with O. P. the smaller buff-coloured globules will be dissipated throughout the bead, causing more turbidity with a slight shade of buff in it; but the red resinous globules remain unchanged, appearing white-hot in the red-hot bead (from which it appears that their fusing-point is higher than that of B), and may be collected, from their superior specific gravity, at the bottom of the bead, by careful manipulation with the point of the blue pyrocone, into one large globule. 63. Professor Stokes has found that, by treating this B bead with distilled water, the general mass is dissolved, while the contained globules remain intact, the most minute of which may be thus perfectly extracted. They may be also extracted more quickly, but with less precision, by wrapping the bead when quite cold in paper, and tapping it gently upon an anvil with a light hammer, when the matrix breaks away from the globules. Added to a bead of P under O. P., the red globule first fuses to an intensely lemon-coloured mass on the surface, and then actions of ceric oxide. dissolves in the glass with effervescence, giving the reThese red ceric globules have been discovered by Professor Stokes to contain also oxide of didymium, the absorption-bands of which, when spectroscopically examined, they show very distinctly. 64. It is therefore assumed that the red balls are composed of ceric + didymic oxides, and the buff-coloured ones of lanthanic oxide; while the turbidity is proved beyond reasonable doubt to be caused by lime, which with baryta are the only substances, except phosphoric acid, capable of causing this opaline turbidity on first application to the B bead. At any rate, the so-called " pure oxide of cerium" is thus shown, by one simple operation, to consist in reality of no less than four substances. This was written before the writer knew how to extract these globules: vide next paragraph. t A trace of phosphoric acid applied to a bead of boric acid, and heated in O. P., affords a glass when cool having an almost perfect resemblance to an opal, Lime, Strontia, Baryta, Alumina, Silica, and Magnesia. The 66. Strontia forms large, beautiful, vitreous-looking globules, quite transparent and even refractive; they have great specific gravity, and can be easily aggregated at the bottom of the bead. Baryta affords sphericles like fisheyes, transparent at first, but soon becoming opaque. Magnesia is not at first acted on by B, but after a short O. P. resolves itself into opaque, white, and compact sphericles, like miniature snow-balls; these, after long O. P., and consequent exhaustion of B, are clarified and become transparent, but are again rendered opaque by the addition of fresh B. It is concluded from this fact that these contained balls have a fixed relative proportion as regards quantity to the containing B. Alumina and silica remain as amorphous fragments, and do not congest into globules: those of the former are white and opaque, like pieces of fat; of the latter, semi-transparent. The Alkalies. a moderately dry room for some time, the one containing the potash will in the course of a few hours cloud over, while the other will remain quite clear. Determination of Gases by Vesiculation. 70. The B vesicle by itself will cloud over after a few minutes, but the appearance then is more white than blue; and if the clouded vesicle be approached to the flame of flame almost touches it and shrivels the substance of the a spirit-lamp, this white coating is not removed until the vesicle, whereas in the case of the addition of a trace of potash, the cloud flies as if by magic when the vesicle is even a considerable distance off. 71. The addition of chlorine to the B bead, made by dipping the bead in strong hydrochloric acid and treating as in paragraph 48, apparently causes the vesicle made therefrom to be still more sensitive to the action of gases upon its surface. It clouds over in common air almost the instant it is made. If held over a solution of ammonia clear. If held in a noxious or putrescent gas, creamy or this nubilescence is prevented, and the vesicle remains brownish-white streaks are formed over the surface, which is that afforded by sulphuretted hydrogen, in an atmosphere of which this vesicle becomes rapidly pitted with circular spots, as though it had suddenly taken smallpox. These spots, through a lens, are observed to be round radiated crystals, with a yellowish tinge near the circumference. After a short time they rot into holes. is otherwise clear. But the most characteristic reaction 72. Another curious result of vesiculation is the crys tallisation of the surface, in a moderately damp_atmo the salts formed renders conclusions from their crystallivesicles show these best; but the complicated nature of sation very uncertain. Microscopically viewed, however, these crystals are very beautiful, especially in polarised silicates thus treated invariably crystallise in most elegant light; and it seems at any rate certain that silica and the and beautiful arborescent appearances, the form taken by other salts being usually that of a disk, often of a leaf. 67. Soda, potash, and lithia, appear to be the only sub-sphere, in the course of ten or twelve hours. Boraxstances which dissolve completely in boric acid in any proportion, and hence the value of the latter as a detective agent for them, and also as an alkalimeter; for if a very small trace of soda or potash contained in a mineral or salt be applied to a B bead having globules of cobalt (for instance) suspended in it, those nearest the side where the alkali is applied are dispersed and spread over that side as a pink suffusion. If 5 per cent be added, the sphericles of cobalt disappear, the whole bead is clarified, and assumes a blue colour while hot, but remains pink on cooling. If 17 per cent be added, the bead remains blue on cooling, and (in the case of soda) borax has been formed; but this method would probably be considered incomplete if it did not afford a means of distinguishing between, as well as of measuring, these two alkalies; and this it does as follows: Vesiculation. 68. If the B bead, on the addition to it of the substance to be examined, shows, by the reaction above described, that an alkali is contained in the latter, a fresh bead should be impregnated with a weighed portion of the substance, which should be dissolved as far as possible by an O. P. Then, the bead being rapidly removed from the point of the pyrocone, it should be blown into while redhot with the jet of the pyrogene, which for that purpose should be advanced so as just to touch the ring of the platinum-wire. If the bead be not too cold, the result will be that the whole mass is blown out into a thin clear bubble or vesicle, about seventy times its first size, thus presenting a very large surface of the dissolved substance to be operated on. This vesicle should then be held in the operator's open mouth, and breathed upon for some time, when, if the alkali has contained even a trace of potash (1 per cent of KO affords the reaction), the vesicle will immediately become clouded over with a light blue film of the colour of a solution of quinine when held against the light. If only soda be present the vesicle will remain clear, but will begin to deliquesce. Lithia affords a tarnish like that of breath on a pane of glass, and the vesicle does not deliquesce. 69. This test for potash in presence of soda is so delicate that if two beads, even of borax, one containing a trace of potash, be vesiculated, and allowed to remain in Cobalt, Copper, and Metallic Oxides. 73. The behaviour of these in B has not yet been fully examined, but such as have promise results quite as interesting and important as those which may be derived from that of the earths. For instance, when an ore containing the oxides of cobalt and nickel, previously manipulated as in paragraph 90, is boracically treated as described in par. 61, the cobalt immediately congests into globules, which after O. P. appear blue-black, after H. P. red-purple through a lens; the nickel oxide, on the contrary, remains in amorphous fragments, which are bright green after O. P., and have a metallic lustre after H. P. Cupric oxide forms in O. P. balls of an indigo-blue colour, not easily distinguishable at first from those of cobalt; but in H. P. the cupreous globules immediately give out streaks of the red suboxide, which cannot be mistaken, though, of course, were further proof necessary, the addition of 5 per cent of soda would form a pink glass from the first, and a blue one from the second. Iron oxide remains in amorphous fragments of a black-brown colour with a rusty halo or tinge round them, and is thus easily distinguished. Oxide of uranium forms a stringy black mass with a yellowish opacity round, which the addition of soda dissolves to a bright pea- green bead. Molybdic acid affords many curious and beautiful changes, for a descrip. tion of which there is not space. Silver, Lead, and the Volatilisable Oxides. 74. None of these form either balls or fragments in boric acid, but spread over the whole bead as a milky precipitate, that of silver having a slight pinkish tinge. Nothing, therefore, can be easier than their separation thus from those metallic oxides which form balls or fragments, as the former of these can not only be collected or aggregated into one sphericle, but extracted from the cold bead with the greatest ease, as described in paragraph 63. It is obvious that this process would probably form an | phoric and boric acids lose weight and substance in direct important method of extracting silver from its ores with very little loss; for the boric acid protects oxides contained in it from the direct effect of an O. P., which dissipates pure silver unprotected to the extent of 10 per cent in a very short time. 75. Altogether, as a detective reagent, boric acid seems scarcely inferior even to phosphoric acid, while as a separating one it is quite unsurpassed. Many hypotheses of the formation of these sphericles or balls have suggested themselves to the writer, but none with a sufficient weight of evidence in their favour to be stated here. They may be due (a) to capillary phenomena, (b) to the retention of a certain amount of carbonic acid (for of the "earths" it is evidently only those forming carbonates which produce them), or (c) to some law or principle as yet not fully known. 76. A bead of pure boric acid is evidently more fluid in H. P. than in O. P., and the hydrated appearance of cobaltine balls in the former (paragraph 73) would seem to suggest the setting free of some constitutional water (?). Phosphate of Lime. 77. This is a useful flux for purposes of mere solution, as referred to in paragraph 39. A curious phenomenon results from the application to the hot glass, containing a metallic oxide in solution, of carbonate of soda, which, instead of fusing in the glass under O. P., does so by itself at first, apparently drawing or precipitating the metallic oxide to itself. If a hot glass of phosphoric acid be applied to warm calcined lime, the mixture takes fire and burns with a very pretty pale yellow light, phosphate of lime being formed. This flux has been little investigated for pyrological purposes, having been thus first used by the writer. proportion after a strong O. P., some means of measuring the diameter of the bead, and of thus keeping it up to the mark, is required. Sufficient accuracy for this purpose seems to be afforded by a simple instrument, as that shown in Fig. 5, representing a common glass tube which exactly covers a 50-mgr. bead of phosphoric acid. The graduations on the outside of the tube are for the purpose of showing the length of the platinum-wire (in tenths of an inch), which of course is proportional to its weight, the thickness or diameter being the same. 79. Fig. 6 represents the instrument with which the platinum-wire is twisted into a loop, which must be perfectly circular, and of a diameter corresponding to the size of glass required. It is a pair of common cagemaker's pliers, with round but tapering legs; only the right (or left) leg should be graduated and figured, say, in tenths of an inch, to show the diameter of the loop made on the other one. Neither of these instruments, however, is to be understood as at all dispensing with the use of the assay balance, of which a beautifully portable description is now made cheaply at Freiberg; it indeed is indispensable, and to be referred to when any doubt is entertained. than to have it and not use it; but in practice it will be found that there are comparatively few substances which injure platinum-foil when heated through it, to such an extent that it cannot be advantageously used for months. The ore called "stibnite" is one of these, but with care even galena may be thus innocuously roasted. 81. The foil, which should be thicker than the usual English kind, can be conveniently made into a small tray about 15 × I inch, and held, as in Fig. 7, with a pair of brass pliers having steel legs, the subject of examination being deposited as a paste (made on a slab with distilled water) on its lower lip. The point of the pyrocone must then be applied to the back of the tray opposite the substance, and on no account is it to be directed upon its surface. 82. It will be found that only a certain and normal, not an uncertain and irregular, degree of heat can thus be applied to substances which under pyrological conditions combine with oxygen or are reduced to the metallic state; and therefore that oxidation on the one hand is as exactly regulated as though it had been controlled by a balance, and that reduction on the other hand need not be feared, except in the case of the very fusible metals, as antimony or lead. For instance, copper pyrites roasted in this way will be found to lose exactly 17 per cent and no more, however long or strongly the pyrocone has been applied. The same amount of sulphur is thus driven off from "copper glance," and there can therefore be little reasonable doubt that 17 per cent is the extent to which sulphur may be dissipated from copper ores without fusing both together. Sublimation. senic oxide as an orange one, in consequence, it is presumed, of the ability of the latter to carry up a portion of the red iron oxide with it. This would appear to afford a valuable distinction between these two metals in toxicological cases, which even Marsh's test does not give. 84. If flowers of sulphur be treated in this way, and the upper leg of the forceps be sufficiently high to be out of its blue flame, for of course it ignites, the steel leg will not be found to have changed further than by being covered with a yellow varnish, which is apparently dis tilled sulphur; but if the leg be plunged warm into water, it will appear white, from the number of bubbles caused by some chemical action upon it. If instead of sulphur only, a mixture of sulphur and anyi nor anic substance containing nitrogen, as gunpowder (only icourse, for this purpose, that must be well watered and groundi to a paste), be used, we shall find the forceps apparently unchanged; but after being plunged warm into water, the upper leg will come out perfectly black. No bubbles will be observed through the lens, but the leg, on drying, will be found covered with rust. 85. This curious reaction is also produced when sulphur is thus sublimated in company with such minerals as emit an empyreumatic or nauseous odour when heated in a matrass alone, as, e. g., stinkstone. Such minerals, dissolved in a P glass, give also the nitrogenical reaction referred to in paragraph 48; and one of such (a black mineral found at Mussoorie, in India, as hard as topaz, though consisting apparently only of silica, and emitting a smell of burnt fat when heated in a matrass), produced, when dissolved to a supersaturated extent in borax, a fine cerulean-blue bead of extreme hardness.* Both this mineral and gunpowder (the latter alone, the former combined with sulphur) were found, when ground with water in agate mortars, to give them a deep violet tint, best FIG. 8. 83. This is better performed on such a platinum tray held by steel-legged forceps than in the ordinary manner on charcoal or in a glass tube. By mixing a little com mon rust or lime with arsenic or antimony, the most timid operator need not fear injury to his platinum, which, however, it is far better to spoil than to lose a single valuable reaction. The addition of iron sesquioxide has another advantage; for it will be observed that the antimonial oxide mixed with it is deposited on the upper steel leg of the forceps unchanged as a white sublimate, but the ar seen by transmitted light, which is quite ineradicable even by the strongest acids.t 86. If sulphur and clear drinking water be heated as at ac, Fig. 7, a white sublimate is deposited on the polished leg of the forceps, similar in appearance to that afforded by fusing chloride of sodium. It was thus extracted, though in extremely minute quantity, from even distilled water, To observe slight sublimates, the steel legs of the forceps should be polished bright before use, and then pointed downwards near a window, when the slightest deposit will affect the appearance of the shining surface through a lens. 87. The distinction made by writers on the "blowpipe " between sublimates of metals by means of the different distances at which they are deposited from the assay on charcoal, is apparently based on an error, as these seem to be due chiefly to the violence or weakness, as the case may be, of the superposed blast (paragraph 7). This may be proved by causing the sublimate of the same metal, as antimony, to be deposited at different distances, as shown at Fig. 8, at cc c, through modified blowing. 88. The same figure shows the manner in which it is * Can the blue colour of the sapphire be due to this fact? + Nitrate of silver gives the agate a purplish-black tint. NEWS proposed to utilise the whole effects of the hydrocarbonous pyrocone for substances which cannot be conveniently supported on platinum wire, as metals or FIG. 9 alloys, by which the defects of large pieces of charcoal in breaking up and spreading out the pyrocone, and in absorbing and wasting so large an amount of heat, may be avoided. This is by sawing charcoal paste (made of C powder, flour, and water according to the directions given in Plattner's work) into parallelograms about 1 inches long by inch deep, and bevelling or slanting off one end as at b. This is called a "charcoal mortar," and is supported by a common sewing-needle stuck into one side, as at a, Figs. 8 and 10. A cavity is scooped at first in the slanting face of the mortar with the point of a penknife, or, better, an implement like Fig. 9, which is the representation of a broken drift. After some use the mortar burns away as shown in Fig. 10; but no fresh cavity requires to be scooped, as the assay, being hotter than the surrounding paste, burns a place for itself, while the great advantage is obtained by the operator of being able to instantaneously cool and examine the assay at any time, by dipping the whole in a cup of water. alloys, or metalliferous ores wrapped in a piece of soda" paper, instead of upon charcoal,-the advantages being cleanliness, portability, and even economy, for one strip will last out any number of pieces of charcoal. It is rapidly attacked, however, by chlorides and phosphates. 90. [Minerals heated in P. P. upon Al. foil. afford extremely valuable indications of some oxides, which on charcoal would be fused and reduced, as, e. g., Kupfer nickel and Speisscobalt, which thus immediately yield a fine green oxide-" emerald nickel." (6th August, 1872.)] PROCEEDINGS OF SOCIETIES. MANCHESTER LITERARY AND PHILOSOPHICAL SOCIETY. Ordinary Meeting, February 4th, 1873. J. P. JOULE, D.C.L., LL.D., F.R.S., &c., President, in the Chair. "On a Large Meteor seen on February 3, 1873, at 10 p.m." by Prof. OSBORNE REYNOLDS, M.A. On the 3rd of February (that is, yesterday), at 10h. 7m. (as afterwards appeared, by my watch (which was 7 minutes fast), I was walking from Manchester along the east side of the Oxford Road (which there runs 30° to the east of south), I had just reached the corner of Grafton-street, when I saw a most brilliant meteor. I first became aware of it from the brightness of the wall on my left, i. e., on the north-east, which caused me to turn my head in that, the wrong, direction; the first effect was that of a flash of lightning, but it continued and increased until it was equal to daylight. On lifting my head I saw directly in front of me, what had previously been hidden by the brim of my hat, a bright object, apparently fixed in the sky, as though it were coming directly towards me; immediately afterwards it turned to the west, and passed just under the moon (which it completely outshone). I was very much startled when I first caught sight of it, owing doubtless to the rapidity with which it was increasing in size and the directness with which it seemed to be coming. The next instant I saw that it was only an extraordinary meteor. It passed the moon, falling at an angle of I should say 20°, and then ceased suddenly, having traversed a path of about 90°, from the south to the east. The colour of the light was that of a blue-light, or rather burning magnesium. The sky was cloudy, but there was no appearance of redness about either the head or the train. I endeavoured to fix its course by the stars, but it was too cloudy, although I could see here and there a star. The conclusions I came to, there and then, were that its course must have been nearly parallel with the road, which by the map runs, at that point, 30° to the west of north; that when I first saw it, it was about 40° above the horizon and due south; and that it passed about 20° to the north of the moon. (This would make its line of approach from Pegasus). While I was thinking of its course I heard a report, not very loud, but which I connected with it. I judged it was about 30 seconds after the display. I then looked at my watch; it was 10h. 7m. I then walked along, talking to a fellow-traveller who had not quite recovered his alarm. Presently we heard a loud report, like a short peal of thunder or the firing of a large cannon. I immediately looked at my watch; it was then Ioh. 10m., so that this second report was from three to four minutes after the display. I have no doubt that this was the report of the meteor, for compared with the other it was like the firing of a cannon to a musket. The time of the second report would make the distance 30 or 40 miles, so that it would have passed over Chester and burst over Liverpool. In this case it must have been a tremendous affair, for the sky was cloudy, and I do not |