CHEMICAL NEWS, Dec. 15, 1865. constantly neighbours, while in the latter a molecule may completely change its place in the liquid, and also that in liquids a molecule may perform complete rotations round axes through its centre of gravity, while in solids this is not generally possible. In a perfect gas a molecule is supposed to be under the action of other molecules, only for a portion of time inde. finitely small with respect to the whole time of motion, and its centre of gravity describes a polygonal path, only changing its direction of motion upon the near approach of the molecule to another molecule, or to a containing vessel, which may be considered as equivalent to an impact. In an imperfect gas a molecule is supposed to be under the action of other molecules during a finite portion of the whole time of motion, this portion increasing as the gas approaches its state of saturation. Between the molecules of a body, and the atoms of a molecule, the luminiferous ether is supposed to exist. The vibrations in the ether which constitute radiant heat and light, are considered due to the vibrations of the atoms in the molecule, and not to the motion of the molecule as a whole; the latter bearing some such relation to the ether as a bell or a stretched string does to the air, the internal vibrations only in the two cases causing the vibrations in the surrounding media, which give rise respectively to light and sound. It appears obvious that as the motion of a molecule of a body as a whole increases-that is, as the temperature rises, the internal motion in the molecule also increases, considering that the action of one molecule upon another must be due to the mutual action of atoms, or to the interatomic forces, it seems probable that the internal vis viva in a molecule, to which the light is due, is proportional to the vis viva of the molecule as a whole, to which heat is to be referred. Thus, as the temperature of a body rises, the internal vis viva in the molecules increases, and the vis viva communicated to the ether also increases; hence the intensity of the vibration in the ether increases, and at the same time the period of vibration diminishes, or waves of shorter length are continually produced with increasing intensity. Hence, as the temperature of a body rises, radiant heat is given off, the intensity corresponding to a given wave length constantly increasing, at last then vibrations in the ether, with wave lengths corresponding to the extreme red of the spectrum, will be caused with sufficient intensity to be visible, and thus the body will begin at first to glow with red light; as the temperature still rises, and vibrations of shorter and shorter wave lengths become of visible intensity, the light emitted will gradually change from red to white. of vibration all included in a certain set; these vibrations will consequently cause vibrations in the ether corresponding only to certain definite wave lengths. Hence the spectra of such incandescent vapours will be broken, and consist only of a series of fine lines. With imperfect gases, or vapours not far removed from their points of saturation, the intermediate phenomenon of spectra broken, but consisting of bands, is to be expected: when, however, the temperature of such vapours is sufficiently increased, a change from spectra consisting of bands to spectra consisting of fine lines is to be looked for. This change has been observed in many cases. When a solid body is incandescent, the light emitted so as nearly to graze the surface may be considered due mainly to the surface molecules; but these being free on the side of the surface, but affected by other molecules on all other sides, the internal vibrations in these surface molecules will have a bias in a direction perpendicular to the surface. Thus the vibrations caused in the ether, which are propagated nearly grazing the surface, will preponderate in a direction perpendicular to the surface, or considering the vibrations in plane polarised light to be perpendicular to the plane of polarisation, the light emitted by such a body, so as to pass close to its surface, will be partially plane polarised, the plane of polarisation being parallel to the tangent plane to the surface of the body at the point of emission. In the case of an incandescent gas, the surface molecules are continually changed, and as a molecule may arrive at the surface in any position, and is equally free on all sides, all trace of polarisation in this light will be destroyed. The fact that incandescent metallic plates do emit partially plane polarised light in directions nearly grazing the surface, the plane of polarisation being parallel to the surface, and that incandescent gases emit unpolarised light, has been observed by Arago. As the molecules at or near the surface of solids or liquids can cause vibrations in the ether, giving rise to emitted light, it is to be expected that, in some cases at least, it will be possible for light, if of sufficient intensity, when incident upon a body, to cause vibrations in the atoms constituting the molecules near the surface; but considering the difference of mass of the atoms of the body and of those of the ether, that the atoms of the body will vibrate slower than those of the ether, the actual times of vibration depending, however, upon the molecular forces in the body. As these atomic vibrations will again affect the ether, such bodies will or may become luminous, the wave lengths of the emitted light being, however, longer than those of the incident light which causes the disturbance in the body. This emitted light will necessarily last some time after the incident light is removed, for the vibrations in the body will not cease as soon as the cause of disturbance is From Draper's law that all bodies become incandescent simultaneously, as well as from other considerations, it seems probable that in all bodies the internal vis viva in the molecules bears the same ratio to the vis viva of the mole-removed, but in general it is to be expected that this cule as a whole. In solid and liquid bodies, the molecules being constantly under their mutual actions, and these actions being subject to constant change from the varying relative positions of the molecules, the atoms cannot assume any definite periods of vibration, but are constantly changing the time of vibration; hence the vibrations in the ether will be constantly, and with extreme rapidity, changing their periods. This change having apparently no limit, and the effect upon the eye continuing for a finite time, light of all wave lengths will appear to be given off simultaneously by such bodies when the temperature is sufficiently high; in other words, incandescent solids and liquids will appear to give off white light, which when analysed by a prism will yield a continuous spectrum. In the case of an incandescent gas or vapour sufficiently removed from a state of saturation to be considered perfect, the atoms will be left to vibrate under the action of the interatomic forces only, and will thus assume periods | emitted light will speedily disappear, though cases may occur in which it will continue for a considerable time. These probable deductions from the assumed principles coincide exactly with the phenomena of fluorescence and phosphorescence (not including in this term cases in which light is emitted by bodies undergoing slow combustion), all fluorescent bodies being phosphorescent for times of different, though in all cases at present observed, of very short duration. ACADEMY OF SCIENCES. M, H. ST. CLAIRE DEVILLE read a note "On the Hydrau licity of Magnesia" of considerable industrial importance. He said that seven years ago M. Donny sent him a specimen of magnesia prepared by the calcination of the chloride. Some of this, which was in compact anhydrous lumps, he left for several months under a tap in his labora Thus the substance appears to be essentially a crystallised hydrate of magnesia, like brucite, which does not absorb carbonic acid. To prove that it really was so, M. Deville prepared magnesia by calcining the nitrate, powdered it, made it into a semi-plastic mass, and sealed it in a tube with some boiled distilled water. After some weeks the mass became as hard and compact as the other, and also crystalline and translucid. After drying in the air this mass was found to have the composition HO30'7,Mg069*3, showing it to be a simple hydrate of magnesia. With similar magnesia the author took casts of medals, as with plaster of Paris, and on placing the casts in water found them to assume the appearance of marble. M. Balard's magnesia—that is, the magnesia prepared by calcining the chloride obtained by the treatment of sea-water,-calcined at a red-heat shows astonishing hydraulic qualities. Calcined at a white-heat for hours its hydraulic qualities are in part destroyed. A mixture of chalk or marble and magnesia forms with water a plastic mass, which after remaining some time in water becomes extremely hard. With a mixture of equal parts of this magnesia and powdered marble, the author hopes to make busts which by hydration will be converted into artificial marble. A mixture of plaster of Paris and magnesia he finds to break up under water. The next experiments are of great importThe author finds that a dolomite rich in magnesia when calcined below a dull red-heat and powdered and made into a paste, forms under water a stone of extraordinary hardness. M. Deville exhibited to the Academy specimens he had made with the dolomite used by Messrs. Bell, of Newcastle, for making Epsom salts by Mr. Pattinson's process. When the dolomite is strongly ignited and some quick-lime produced, the mass does not set so well, crystals of arragonite separating in thin veins. When dolomite is heated to bright redness, and all the chalk converted into quick-lime, the paste formed with it breaks up in water. All the experiments, M. Deville states, show that the magnesia is the binding material, which in becoming hydrated holds together the particles of chalk or marble to form a compact homogeneous stone. He has exposed some of the stones to the action of the sea in the port of Boulogne, and they at present remain unaltered. The facts contained in this note proved the perfect hydraulicity of pure magnesia by the formation of a definite hydrate. ance. The experiments with dolomite are of the most importance to us, and no doubt some of our readers will follow up the experiments made by the accomplished author of this note. M. Cloez presented a third memoir “On the Oxidation of Fatty Vegetable Oils." It contains nothing that the author has not said before; but we give a summary. It has been commonly supposed that the presence of albuminoid matter, mucilage, &c., in vegetable oils promote their oxidation. This, M. Cloez assures us, is not the fact. Oils perfectly free from such matters oxidise as rapidly in the air as those contaminated by them. He then proceeds to show that the resinification of oils is owing to the subtraction of carbon and hydrogen and the addition of oxygen. Only a part of the carbon disappears in the form of carbonic acid, the rest escaping in the acid, acrid, suffocating vapours which give the odour called oxidation rancid to the oil. When the oxidation takes place in a confined space these acid vapours accumulate, and may produce bad effects on animals or individuals who breathe them. Among the vapours will be found formic, acetic, acrylic, and butyric acids, and probably acroleine. Most of these arise from the decomposition of glycerine, butyric acid alone resulting from the oxidation of the fatty acid. The elastic, resinous, solid matter left after the complete oxidation of linseed oil has, according to the author, a very complex composition, which he does not attempt to unravel, but only describes its appearance, well known, no doubt, to all our readers. Submitted to the action of heat, oxidised linseed oil, M. Cloez tells us, deepens in colours, swells up, gives off a suffocating odour, succinic acid, inflammable hydrocarbons, and in the end leaves a Boiling water has carbonaceous residue in the retort. little action on the oxidised oil; alcohol and ether dissolve out a thick fatty matter, which, among other substances, contains unchanged margaric and oleic acids. M. Cloez sums up the results of his investigations as follows:-1. All fatty oils, without exception, absorb oxygen from the 2. Elevation of temperature air, and increase in weight. facilitates the operation. 3. Intensity of light also has a marked influence on the progress of the phenomenon. 4. Light transmitted through coloured glass retards the oxidation. Starting from colourless glass, the retardation is increased by coloured glass in the following order :Blue, violet, red, green, yellow-that is, oil covered with yellow glass, oxidises most slowly. 5. In the dark the progresses very slowly. 6. The presence of various matters accelerate oxidation. 7. In the resinification there is a loss of carbon and hydrogen and an assimilation of oxygen. 8. The various oils in oxidising furnish the same products; gaseous and volatile compound acids, unchanged solid and liquid fatty acids, immediate principle. Oils oxidised in the air no longer and a solid, insoluble matter, which appears to be a definite contain glycerine. 9. Lastly, drying oils do not differ chemically from the non-siccative oils. M. G. Jean sent a note "On Ozone, and the Splitting up of Carbonic Acid into Ozonised Oxygen and Carbonic Oxide, under the influence of Electricity.' The author employed an induction coil, provided with a peculiar condenser, for dividing the spark into an infinite number of very feeble sparks. By this apparatus, he says, he proved that carbonic acid, under the influence of the sparks, split up into carbonic oxide and oxygen; and the odour and other tests showed that the oxygen was strongly ozonised. Atmospheric air exposed to the same influence becomes ozonised, and forms nitric acid (?), which suddenly decomposes into nitrous acid when the air is heated. There are some other curious things in the note, from which we shall only further quote the account of the properties of ozone. Özonised oxygen, the author says, has the property of giving rise to vapours when mixed with sulphurous or nitrous acids, and these vapours are very persistent in the presence of ammonia and iodine. Crystals of iodine dropped into a vessel of ozonised oxygen also gives rise to a very thick vapour, which gradually precipitates in the form of iodic acid. A coating of linseed oil on glass exposed to ozonised oxygen became dry in an hour, and its weight was found to have increased by 20 per cent. The quantity actually absorbed, the author stated, must have been much more considerable, for it was dis engaged in the form of strongly-smelling acid vapours. " M. Simonin communicated some determinations of the "Pressure and Temperature of the Air in Mines." His results do not enable him to establish any general laws, but the mean of four experiments at the coal mines of Creuzot and Epinac gave a rise of one degree (C.) of temperature for every 45 metres of vertical descent; and a rise of one millimetre in the barometer for every 10 metres of vertical descent. An account of "The Mineral Waters of Atami, Japan," by M. Lemoyne, was read. The source of these is an M. J. E. Petrequin re-opened the case "Ether v. Chloro- M. Velpeau addressed the Academy, and said that he had had many thousands of patients under chloroform, and had never lost one by it! He thought that ether and chloroform might have their respective advantages, and it would be well to keep both in use. M. Villemin presented a note "On the Cause and Nature of Tuberculosis,” in which he showed that this disease is communicable by inoculation. He inoculated some rabbits with tuberculous matter from the lung of a man who had died of phthisis, and in every instance found tubercles in the lungs of the animal, and often deposits in other parts of the body. The author concludes that tuberculosis is a specific affection, and that its cause resides in an inoculable agent. The disease may, therefore, range nosologically by the side of syphilis, but stands nearer to glanders. NOTICES OF BOOKS. again caught by a plant, and now fixed in a grain of wheat; then becoming part of a human organism, to be again cast forth and enter a tree; and in time, reduced to charcoal, enter a steel blade, in which stage of existence it witnesses fearful scenes of bloodshed. But "when," says the atom, "I speak of these scenes as fearful, I make use of a human expression; for I need scarcely say that death has no terror for an undying atom." The atom follows his history a few stages further, and then concludes : "Such is the story of my life, or, rather, of a fragment of my life. I enjoy perpetual youth. To-day I may be buried in a mass of corruption; but to-morrow I may form part of a newly-opened rose. Time cannot reach me; his hour-glass may be shattered and his scythe broken, but still I shall exist. At the present moment I am joined to countless other atoms, indestructible and eternal like myself, in a fragment of sugar; but who can tell where I shall be in a year's time?" We might make almost any number of quotations as interesting as that above; but we prefer to commend the entire book to our readers as the best we are acquainted with to give a studious youth. A word of praise must also be given to Mr. C. H. Bennett for his drawings, which are full of humour, and in some cases eminently suggestive. NOTICES OF PATENTS. SIX MONTHS. GRANTS OF PROVISIONAL PROTECTION FOR 2892. T. Redwood, Montague Street, Russell Square, Middlesex, "Improvements in the preservation of meat and the concentration of its juices."-Petition recorded Nov. 10, 1865. 2934. J. T. A. Mallet, Boulevart St. Martin, Paris, "A new or improved process for the manufacture of oxygen."-Nov. 14, 1865. 2970. G. Taylor and J. Fernie, Leeds, “An improvement in the manufacture of steel castings."-Nov. 18, 1865. 3009. T. Redwood, Montague Street, Russell Square, Middlesex, “Improvements in the preservation of animal substances, such improvements being especially useful when these substances are intended for use as food."Nov. 23, 1865. 3025. W. A. Lyttle, General Post Office, London, "Improvements in furnaces."-Nov. 25, 1865. 3043. W. R. Lake, Southampton Buildings, Chancery Lane, " Improvements in the mode of, and means for, preserving fruit and other perishable substances."—A communication from B. M. Nice, Cleveland, Ohio, U.S.A. J.-Nov. 27, 1865. The Fairy Tales of Science. A Book for Youth. By Ar this season of the year there are always anxious parents 3047. C. H. Newman, Chertsey, Surrey, "A new kind of unfermented and unintoxicating malt liquor, which shall keep sound for any period of time."-Nov. 28, 1865. 3067. C. S. Baker, Fleet Street, London, "Improvements in the process of treating materials for the manufacture of paper and other similar textile fabrics, and in apparatus for the same."-A communication from R. H. Collyer, Pont An-demer, Eure, France.-Nov. 29, 1865. CORRESPONDENCE. The "Cosmos" and the Poisoning by Mercuric Methide. To the Editor of the CHEMICAL NEWS. SIR,-Your French correspondent, referring, in your last number, to the recent letters in the Cosmos about the poisoning of the two assistants, Dr. C. U— and Mr. T. C, in the chemical laboratory at St. Bartholomew's Hospital, has given a very extraordinary misrepresentation of the facts, which I can hardly attribute to his imperfect knowledge of the French language. In my usual "English T. L. PHIPSON, Ph.D., F.C.S., London, December 9. [We insert the part of Dr. Phipson's letter which concerns our correspondent, but must decline to make the CHEMICAL NEWS a vehicle for other recriminations. ED. C. N.] Utilisation of Soda Waste and Chlorine Residues. To the Editor of the CHEMICAL NEWS. SIR,-On reading M. Kopp's last letter, in No. 313 of the CHEMICAL NEWS, I am particularly struck with the coincidence of his results with my own experiments. As a labourer in the same field, it gives me much pleasure in confirming his figures. His plan of oxidising the alkali waste is very simple and ingenious, and I would also expect that it will work effectually. I see, however, that M. Kopp still remains under the impression that his process is quite original, and that it has not been patented in England. To correct this, allow me to refer him to Townsend and Walker's patent, No. 3038, dated 11th December, 1860. He will find there the identical process which he now describes, and from which permit me to give a brief quotation :"First, the solutions (sulphide of calcium and still liquor) may be mixed in such proportions that the resulting precipitate will consist chiefly of sulphur. "Second, the solutions may be so proportioned that the resulting precipitate will consist chiefly of free sulphur and sulphide of iron. "Third, the solutions may be so proportioned that the precipitate will consist of free sulphur, sulphide of iron, and sulphide of manganese." ganese the more will the sulphur be retained in the burned precipitate, and with some varieties not more than ten cwt. of sulphur could be obtained from two tons of precipitate. In adopting any new process, I consider that the most adverse facts should be looked full in the face; and I only point out these drawbacks not to deter any one from adopting it, but simply that the process should be estimated at its real worth. It would be strange, indeed, if I would deliberately conat to perfect. As it stands, it is only a partial success. At demn without reason a process which I laboured so much least one-third of the sulphur is lost after being precipitated, and the residue is absolutely worthless unless some use can be made of sulphate of manganese. I would suggest as an improvement on M. Kopp's proposed arrangement of processes that the manganese should not be precipated at all, but that the process should be conducted in accordance with the second proposition in Townsend and Walker's patent, adding M. Kopp's proposal to utilise the sulphuretted hydrogen. By this means obtained, and all the sulphur would be recoverable as sula precipitate containing 70 per cent. of sulphur would be phurous acid, leaving very little residue. As to priority of invention, I can only say that the processes were devised by Mr. Townsend and me five years ago, quite independent of any knowledge of M. Kopp's labours in the same direction; and if M. Kopp knew and published all the facts as they stand described by us before that time, he is then entitled to claim priority. I am, &c. JAS. WALKER. 275, St. George's Road, Glasgow, Dec. 11. MISCELLANEOUS. Chemical Society. The next meeting of this Society will take place on Thursday evening next, at 8 o'clock, when a paper, by Mr. J. Yates, will be read, "On the Material for Mural Standards of Length." Royal Institution of Great Britain.-The following are the lecture arrangements for the ensuing season:-Christmas Lectures, 1865, adapted to a juvenile auditory.-Prof. Tyndall, F.R.S., six lectures "On Sound." Before Easter, 1866.-Prof. Tyndall, F.R.S., twelve lectures "On Heat;" Prof. Frankland, F.R.S., eight lec"On Chemistry;' " Prof. R. Westmacott, R.A., F.R.S., six lectures "On the Way to Observe in Fine Arts; "Rev. G. Henslow, four lectures "On Structural and Systematic Botany, considered with reference to Frankland, F.R.S., four lectures "On Chemistry;" G. Education and Self-instruction." After Easter.-Prof. tures It will be observed that these propositions deal essen-Scharf, Esq., Secretary and Keeper of National Portrait tially with solutions, and not with the alkali waste itself, as M. Kopp has supposed. The composition of the precipitates obtained as above tallies closely with that given by M. Kopp; the first gives 90 per cent. sulphur, the second 70, and the third 45 to 50. It is in dealing with the third precipitate that the stumbling-block occurs which I referred to in my last letter; and I can assure M. Kopp that many were the resolute attempts to remove it, but all in vain. There it stands still, as ugly as ever, and the figures given by M. Kopp establish this beyond a doubt. He commences with a precipitate containing 50 per cent. sulphur, which he calls a sulphuretted sulphuret of manganese; but I look upon it as simply a mixture of sulphur, sulphide of iron, and sulphide of manganese. From two tons of such a precipitate he obtains 14 to 16 cwt. of sulphur, in the form of sulphurous acid; the other 4 to 6 cwt. remains combined with the manganese in the form of sulphate. This may be looked upon as the most favourable results which could be obtained, as it will vary with the description of manganese ore used; the purer the man C. Kingsley, M.A., two lectures "On Science and SuperGallery, three lectures "On National Portraits;" Rev. stition;" Prof. Huxley, F.R.S., twelve lectures "On the Ansted, F.R. S., five lectures "On the Application of PhyPhysiological Methods and Results of Ethnology;" Prof. sical Geography and Geology to the Fine Arts; course may possibly be given by Dr. Du Bois Reymond "On Electric Fish.' an extra ANSWERS TO CORRESPONDENTS. Dr. Muspratt.-Next week. E. Osborne-The proportions are given in Dr. Stenhouse's patent small percentage of the paraffine. specification. Boiled oil is used to the extent Dr. Calvert says-a H. H.-There is a French book on the subject of pyrotechny; but we know of no separate work in English on the subject that is not very old. The last volume published of Knapp and Richardson's "Technology" has an excellent article on fireworks. Clericus.-Aniline black is formed on the material dyed purple by treating the fabric with a dilute solution of bichromate of potassium, No aniline black is sold that we know of. or according to Lanth's process. See CHEMICAL NEWS, vol, xi., p. 65. Received,-John Cliff; A. G. Anderson, next week. Dec. 22, 1865. (Continued from page 280.) ON commencing the account of his own researches, the author first mentions the source of the naphtha used in the experiments. It was obtained from various American gas works in which, however, cannel and Newcastle caking-coal were chiefly employed. In some a Pennsylvanian caking.coal was also used. The coals were employed in the same proportions as in England. The process for purifying the naphtha was the same as that in use here-namely, treatment with oil of vitriol and alkali, and subsequent rectification and fractionation. Very large quantities were operated upon to ensure the detection of any constituent which might be present in small proportion. The process of fractioning was continued on the large scale until the separations had so far progressed that at certain temperatures a full barrel of distillate would come off from the ten barrel still employed without a variation of more than one or two degrees of the thermometer. Finally, a sample gallon was taken from each of the barrels composing the last series of products, and then set aside for the laboratory investigations. In the laboratory the fractionings were made by the author's process of fractional condensation described ante p. 85. They were continued until the whole of the naphtha taken, boiling between 80° and 170°, had accumulated at the four points indicated-viz., at 80°, 110°, 140°, and 170°, or so nearly the whole that the intermediate quantities had become too small to admit of being further operated upon. Having so thoroughly exhausted the intermediate fractions, Mr. Warren says, I can have no hesitation in asserting that no other body than those alluded to was present in the naphtha-at least, in appreciable quantity hence that the parabenzole of Church was probably only a mixture of benzole and toluole. On some Properties of the Bodies obtained by immediately at 97°. The distillation occupied an hour and ten minutes, during which time the thermometer rose only o6°, being fifty minutes in rising o‘2° from 79°4° to 79.6°, at which temperature it had distilled nearly to dryness. Height of the barometer during the experiment reduced to o° 761'9 mm. Taking 79'4° this being the average of the last five observations, and applying the corrections for the upper column of mercury and for atmospheric pressure, according to the directions given by Kopp, we find the corrected boiling point of benzole to be 80'1o. Analysis. (In most cases we abridge the details of the determinations) o°2339 of benzole gave by combustion in a stream of oxygen gas 0.7903 of carbonic acid, and o.1683 of water. Calculated. Found. Density of vapour found 2.698 II. Toluole.-Sp. gr. 0.8824 at 0° and 0.872 at 15o. The preparation used for determining the boiling point was repeatedly boiled with sodium. The experiment was conducted as with the benzole. Operating upon a considerable quantity the distillation occupied about an hour. It commenced at 110'69; two minutes later the temperature had fallen to 1104°, at which point it remained absolutely constant for forty-eight minutes. Five minutes later the temperature had risen again to 110.6°, and five minutes later to 1108°, at which point the operation was suspended. The corrections made as in the case of benzole gives 1103° as the corrected boiling Church remarks that toluole when point of toluole. distilled in the ordinary manner is liable to become oxidised, and its boiling point thereby raised in consequence of the upper part of the retort becoming heated above the boiling-point of toluole. He found that the toluole which by ordinary distillation had come over between 108° and 109° would distil eight tenths between 103° and 104°, after repeated rectification with sodium. I would therefore state that my preparation of toluole was never subjected to a higher temperature than its boiling point; and that I have never noticed any reduction of the boiling point of this body by purification with sodium. Analysis.-01628 grm. of toluole by combustion in a stream of oxygen gave o'5447 of carbonic acid and 0·1315 of water. Calculated. Found. Carbon C14 84 91'3 91'20 8 8.7 8.97 I. Benzole.-Sp. gr. 0.8957 at 0°, and 0.882 at 15.5°. The experiment to determine the boiling point was conducted in a tubulated retort, operating on 150-200 C.C. of the benzole, containing some pieces of sodium. The benzole employed had previously been repeatedly boiled with sodium until the latter ceased to have any action. The thermometer bulb extended into the liquid† nearly to the bottom of the retort. A second thermometer was attached by means of flexible bands to the side of the one in the retort; the bulb being placed during the ebullition at a point midway between the centre of the cork (-5) and the upper end of the mercurial column -viz., at 35°. A paper screen closely fitting the thermometer spindle was placed across at the top of the cork. With the retort neck slightly inclined upward III. Xylole (Cumole of Mansfield and Ritthausen). and cooled to prevent the escape of vapour, ebullition-Sp. gr. 0178 at 0° and 0.866 at 15.05. The method of was continued for considerable time, until the mercury determining the boiling point was the same as before, in the thermometer ceased to rise. The lamp being re- the xylole having been subjected to the same treatment. moved for an instant, the neck of the retort was turned The quantity operated on was smaller, and the experidownward and quickly inserted in a Liebig's condenser. ment conducted more rapidly. Distillation begun at On replacing the lamp, distillation commenced almost 138.6° and ended 139°, having distilled almost to dryness. Taking the average-viz., 138°4°, and making customary * Abridged from the Memoirs of the American Academy. The author has some critical remarks on the propriety of placing corrections, we find 139.8° to be the corrected boiling point of xylole. the bulb in the liquid, which we shall give on a future occasion. VOL. XII. No. 316. DECEMBER 22, 1865. Theory C1H=4 volumes |