than to have it and not use it; but in practice it will be | senic oxide as an orange one, in consequence, it is prefound 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. sumed, 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. 81. The foil, which should be thicker than the usual English kind, can be conveniently made into a small tray about 15×1 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. 66 Sublimation. 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 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. I 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 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 ground 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. 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. 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. FIG. 10. Aluminium-Foil as a Support. 89. It has been found that pieces or strips of aluminiumfoil, not under 3 inches long, withstand the strongest heat of the pyrogene without fusing as well as platinum does, over which the former metal possesses this great advantage, viz., that many metals, as gold, silver, lead, &c., or their alloys, may be fused upon it without the least fear of combination. It is thus possible to use this beautiful metal as a support upon which to fuse most other metals, 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. teor. 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 meIt 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. 1om., 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 think I exaggerate when I say that at one instant it was as light as day; the train was very long and the speed great. It ceased suddenly, as when a ball from a Roman candle falls into water; there were no fragments, as from an explosion. "Note on Meta-Vanadic Acid," by Dr. B. W. GERLAND. Communicated by Prof. Roscoe, F.R.S. A solution of copper vanadiate in aqueous sulphurous acid, after part of the latter is removed by boiling, deposits brilliant yellow crystals, the description and analysis of which I gave in the Journ. of Pract. Chem., 1871, p. 97. These crystals are quite uniform in appearance, and contain cupric oxide, vanadic acid, and sulphurous acid. They rapidly change under the influence of air, their beautiful metallic lustre soon disappears, and the colour becomes a dark green. Although formed in a solution of sulphurous acid, they nevertheless decompose when treated, after separation from their mother liquor, with fresh sulphurous acid, so that two kinds of crystals, brown and orange-yellow, now appear mixed together. An excess of sulphurous acid dissolves the former and leaves the latter intact. After filtration, washing, and drying, they form microscopic scales of beautiful lustre and a deep yellow-orange colour; they are free from copper and sulphur, and perfectly unalterable in the air. Heated to 100° C., and even to 130°, they lose no weight, but at a low red heat water is given off, and the residuum consists of vanadium pentoxide, which fuses and crystallises after cooling. The composition of the substance, previously dried over vitriol, is, according to analysis, the following: 8.73 91'06 O'21 100'00 In some instances I obtained the same bronze or goldlike substance by treating copper vanadiate suspended in water with sulphurous acid gas, and in many others the effect of the gas was formation of vanadic oxide in solution. I intend to elucidate this point by further experi ments. The copper vanadiate was prepared by precipitation of ammonium vanadiate with copper sulphate. The motherliquor contained both copper and vanadic acid. After evaporation the latter is found in the residue as metavanadic acid, with the same metallic appearance as that just described, and can be obtained by washing with water. The crystals obstinately retain copper, sometimes as much as 12 per cent, which is best removed by repeated treatment with aqueous sulphurous acid. A sample of the substance so prepared was analysed by Prof. Roscoe, with the following results : 8.97 91.03 Weight of substance taken 0'4505 grm. Hence the percentage composition is found to be Water 9'12 90.88 100'00 The samples of vanadium bronze obtained by these three different methods had the same composition, the same appearance, and the same chemical properties. It is essentially distinguished from the amorphous brick-red hydrated vanadic acid by its indifference to reagents. Sulphurous acid scarcely acts on it, neither does ammonia, and even a solution of sodium carbonate dissolves it only after very long-continued boiling. In the air it is perfectly permanent. It is very probable that this meta-vanadic acid will become a favourite bronze, valued even higher than gold. I trust that at some future time I shall be able to render a more satisfactory account of this interesting substance, and particularly of its formation. Dr. WILLIAM ROBERTS exhibited some preparations and experiments bearing on the question of biogenesis. He stated that in the last two and half years he had performed sion that the fungi, monads, and bacteria which make over 300 experiments. His results supported the conclu. their appearance in boiled organic mixtures are not due to spontaneous evolution, but arise exclusively under the influence of pre-existing germs or ferments introduced from without. His method of experimenting consisted chiefly in exposing organic solutions and mixtures to a boiling heat in glass flasks whose necks had been previously tightly plugged with cotton wool. tions of the experiment were adopted : Two modifica. I. In the first modification a 4-ounce flask was em ployed, and the heat applied directly by means of a gas flame. II. In the second modification-after the introduction of the materials to be operated on-the elongated neck of the flask was sealed hermetically by the blowpipe above the plug of cotton-wool; the flask was then weighted with a collar of lead, and immersed in a large can of water; the can was then put on the fire and the water boiled for 20 or 30 minutes. During the process of boiling, the flask was maintained in an upright or semiupright position, in order to prevent any wetting of the cotton-wool plug by the contents of the flask. When the can was cold the flask was removed, and its neck filed off above the cotton-wool, so as to permit free ingress and egress of air. Flasks thus prepared were maintained at a warmth varying from 50° to 90° F. for long periods,—many weeks and months, some in the dark and some exposed to the light, with the following results : I. Simple filtered infusions of animal or vegetable tissues-a very considerable variety were tried-boiled over the flame for five or ten minutes, in flasks previously plugged with cotton-wool, remained permanently barren. This result was absolutely invariable. II. More complex mixtures-milk, neutralised or al kalised infusions of vegetable and animal tissues, similar albuminous and gelatinous solutions, mixtures containing fragments of animal or vegetable substances or cheeseyielded variable results. In none of them did fungoid growths make their appearance, but monads and bacteria frequently appeared in abundance. This seemingly contradictory result was inferred to be due to the ineffective application of the heat in the process of direct boiling over a flame. It was found that many of these more complex mixtures frothed excessively when boiled,-brisk ebullition could not therefore be maintained, particles were spurted about on the sides of the flask, and, in this way, apparently escaped effective exposure to the heat. Even when the boiling was prolonged for 20 or 30 minutes the results were still uncertain,-sometimes the flasks remained barren, sometimes they became turbid and swarmed with bacteria. III. By the second modification of the experiment much more constant results were obtained,-the Ĥasks remained almost always permanently barren,--and the few exceptions were found to be due to some imperfection in the conduct of the experiment. No exceptions occurred with milk, nor with substances, however complex, which were in actual solution; but when considerable pieces of vege table or animal substances were introduced into the flasks, bacteria and monads with putrefactive changes occasionally made their appearance in abundance. In these exceptional cases, when the experiments were repeated with the pieces finely comminuted, or introduced in some other way more favourable to the diffusion of the heat, the flasks remained permanently barren. Dr. Roberts called attention to the crucial significance of experiments on this subject made in flasks whose necks are plugged with cotton-wool. A plug of cotton-wool acts as an absolutely impervious filter to the solid particles of the atmosphere, while it permits a free passage to the gaseous constituents. When one of these experiments is effectively performed, the fluid or mixture in the flask may be exposed to the full influence of light, of warmth, and of air, and yet it remains permanently barren. As sow evaporation takes place the liquid passes through al grades of concentration,-possibly chemical changes of various kinds take place within it, and still no organic growth makes its appearance for months, and even years; but if the plug of cotton-wool be withdrawn for a few minutes, or a single drop of any natural water, however pure and well filtered, be introduced, then all is changed,-in a few days the clear solution becomes turbid from bacteria and monads, or a mass of mildew covers its surface and soon half fills the flask. In the face of these experiments it was impossible to doubt that the biogenic power of the atmosphere resides in its dust, and not in its gaseous ingredients; but as to the exact nature of that biogenic power-whether it be a specific germ or a ferment-no sufficient evidence has yet been adduced. Dr. Roberts did not find that diminished pressure of the atmosphere, obtained by sealing flasks hermetically in ebullition, after the mode suggested by Dr. Bastian, materially affected the results. Dr. R. ANGUS SMITH, F.R.S., said that he was glad to see such uniformity of results. His own experiments, which were very numerous on a similar point, were made differently, but were without exception proving the same. As to the name of the substances in the air, he preferred germ: it involved no theory. A germ may be considered that which germinates. Dust is an equivocal expression which may cause a popular error. Polarity introduces a theory which is so entirely without basis that in our present state of knowledge we may call the inference it presupposes decidedly false. the Matriculation Examination of June next :-That Greek be no longer compulsory on Candidates at the Matriculation Examination, but be ranked as optional with French and German; so that it shall be sufficient for any Candidate to pass in any one of these three Languages. holds the appointment of Analyst for the parishes of Appointment of Analyst.-Dr. Muter, who already Lambeth and St. George the Martyr, Southwark, has Analyst for the district. been appointed by the Wandsworth Board of Works, London International Exhibition, 1873.-The fourth meeting of the Committee on Surgical Instruments and Appliances took place on the 17th inst. at the Royal Commissioners' Offices, Gore Lodge, S.W. The members present were-Mr. Cæsar H. Hawkins, F.R.S., in the chair; Dr. P. Allen; Mr. R. Brudenell Carter; Mr. W. White Cooper; Dr. H. J. Domville, C.B.; Dr. Arthur Farre, F.R.S.; Mr. J. Hilton, F.R.S.; Mr. Liebreich; Mr. J. Lake, F.R.S.; Dr. A. G. Mackay; Mr. J. Marshall, F.R.S.; Mr. T. W. Nunn; Dr. W. S. Playfair; Mr. R. Quain, F.R.S.; and Mr. E. Saunders. The Committee, after transacting the general business of the meeting, considered the applications-more than sixty in number which had already been received. They adjourned until Monday, the 17th March, the date of receiving the goods being Tuesday, the 11th March next. Earliest Discovery of Gas-lighting on the Continent.-From a communication published in the Moniteur Belge, of the 13th inst., it appears that Pierre-Henri Minkelers, born at Maestricht, December 2, 1748, Professor of Chemistry and Physical Sciences, at Leuven (Louvain) University, from 1772 to 1797, when the University was suppressed-(it was re-established in 1831 as the Catholic University of Belgium), made a series of experiments, which resulted in the discovery of gas-lighting on October 2, 1784. This is recorded in a small volume, now very rare, a copy of which is preserved in the library at Maestricht, entitled, " Mémoire sur l'Air Inflammable tiré de Différentes Substances," rédigé par M. Minkelers, Professeur de Philosophie au Collége du Faucon, Université de Louvain: Louvain, 1784. After the suppression of the University, Minkelers was, for a series of years, Professor at the Atheneum of Maestricht, where he died July 4, 1824. One of the streets of the city alluded to, viz., that wherein Minkelers resided, has been named after the savant. Owing to the political disturbances of the time gas-lighting was not then introduced on the large scale. CHEMICAL NOTICES FROM FOREIGN SOURCES. Under this heading will be found an encyclopædic list of chemica papers published abroad during the past week, with abstracts of all susceptible of advantageous abridgment. The two half. yearly volumes of the CHEMICAL NEWS, with their copious indices, will, therefore, be equivalent to an English edition o the "Jahresberichte." NOTE. All degrees of temperature are Centigrade, unless otherwise expressed. Comptes Rendus Hebdomadaires des Séances de l'Academie des Sciences, February 10, 1873. The following original memoirs and papers relating to chemistry are published in this number: Specific Gravity of Absolutely Pure Alcohol.-I. Pierre.Pure vinic alcohol has at o° a sp. gr. of o'815, at 15° 080214; propylic alcohol at 0° 08198, at 15° 080825; butylic alcohol at 0° 0'817, at 15° 0806; amylic alcohol at 0° 0'8253, at 15° 0'8146. The decrease of density at 15° is for-No. 1, 001286; No. 2, 001055; No. 3, 0'011; No. 4, 00107. Respecting the ordinary alcohols and spirits of commerce, the author states that there are no data to judge what influence mixtures of the three last-named with vinic alcohol will exert upon the sp. gr. thereof. Annealing of Glass, and more Particularly on the so-called Batavian Glass Drops.-V. de Luynes. This essay records the results of a series of experiments made with the view to ascertain the cause of the sudden breaking of the well-known glass drops, which appears to be due to an unequal annealing of the glass. Poisonous Properties of the Calcium Salts.-J. Rabuteau and L. Duconday.-A toxicologico-physiological essay, from which it appears that the salts of calcium and potassium are muscular poisons affecting the action of the heart. Incidentally the authors observe that metals are the more poisonous the higher their atomic weight, or the smaller their specific heat. Researches on the Antiseptic and Therapeutic Properties of Silicate of Soda.-M. Champouillon.-The contents of this paper bear upon the effects of silicate of soda as applied to wounds and pus-secreting surfaces. It would appear that the silicate may become useful as an externally applicable agent. Chemical Investigation of a Stalagmitic Product from the Solfatara of Pouzzoles.-S. de Luca.-After giving a detailed account of the mode of formation of this stalagmite, the author quotes its percentical chemical composition :-Sulphuric acid (calculated as anhydrous), 2017: sulphurous acid, 36; arsenious acid, 15; alumina, 79; lime, 69; ammonia (NH,O), 5'3; chlorine, 1'5; protoxide of iron, 14; silica, o'8; water driven off at 100°, 278; phosphoric acid, magnesia, potassa, and soda together, 22.7. Action of Bromine upon Bi-Bromosuccinic Acid; Formation of Tetrabromated Hydruret of Ethylen.-E. Bourgoin.In the first part of this paper the author records at length the mode of preparation of bi-bromosuccinic acid by treating succinic acid with bromine and water at from 165° to 170° in a strong sealed glass tube. From tetra-bromosuccinic acid, obtained by further bromation of the former compound, the author obtained tetra-bromated ethylen, CH2Br; a colourless fluid somewhat like chloroform in taste; below 0° this substance crystallises. Another Aniline Colour.-F. Hamel.-When aniline is treated at the ordinary temperature with chloride of sulphur, there is formed a red-coloured pigment, which is soluble in acetic acid, alcohol, and ether, but water cannot be added to these solutions, as a gray-coloured matter is then precipitated from the solution. The chloride of sulphur should be cautiously added to the aniline, otherwise it becomes carbonised. The red pigment is a solid body, and after evaporation of its solution in alcohol, it is obtained as a deep black-coloured crystalline substance. is obtained. It is a crystalline body, fusing at 75°. Other ketons can be prepared by a similar reaction. Acenaphthen and Naphthalic Acid.-A. Behr and W. A. van Dorp.-Acenaphthen is obtained from coal-tar. It is a solid crystalline body, fusion-point 94 to 94°; yields by oxidation with chromic acid (K2Cr2O,+H2SO, dilute) an acid; formula, C12HO. The calcium salt of this acid yields, by dry distillation with excess of lime, naphthalin; while the acid just mentioned is naphthalin-bicarbonic acidC10H COOH COOH |