Obrazy na stronie


Dec. 15, 1865.

Academy of Sciences.


constantly neighbours, while in the latter a molecule may of vibration all included in a certain set; these vibrations completely change its place in the liquid, and also that in will consequently cause vibrations in the ether correspondliquids a molecule may perform complete rotations round ing only to certain definite wave lengths. Hence the spectra axes through its centre of gravity, while in solids this is of such incandescent vapours will be broken, and consist not generally possible,

only of a series of fine lines. In a perfect gas a molecule is supposed to be under the With imperfect gąses, or vapours not far removed from action of other molecules, only for a portion of time inde their points of saturation, the intermediate phenomenon finitely small with respect to the whole time of motion, of spectra broken, but consisting of bands, is to be exand its centre of gravity describes a polygonal path, only pected: when, however, the temperature of such vapours changing its direction of motion upon the near approach is sufficiently increased, a change from spectra consisting of the molecule to another molecule, or to a containing of bands to spectra consisting of fine lines is to be looked vessel, which may be considered as equivalent to an impact. for. This change has been observed in many cases.

In an imperfect gas a molecule is supposed to be under When a solid body is incandescent, the light emitted so the action of other molecules during a finite portion of as nearly to graze the surface may be considered due mainly the whole time of motion, this portion increasing as the to the surface molecules; but these being free on the side gas approaches its state of saturation.

of the surface, but affected by other molecules on all other Between the molecules of a body, and the atoms of a sides, the internal vibrations in these surface molecules will molecule, the luminiferous ether is supposed to exist. have a bias in a direction perpendicular to the sịurface.

The vibrations in the ether which constitute radiant Thus the vibrations caused in the ether, which are propaheat and light, are considered due to the vibrations of the gated nearly grazing the surface, will preponderate in a atoms in the molecule, and not to the motion of the mole- direction perpendicular to the surface, or considering the cule as a whole; the latter bearing some such relation to vibrations in plane polarised light to be perpendicular to the ether as a bell or a stretched string does to the air, the plane of polarisation, the light emitted by such a body, the internal vibrations only in the two cases causing the so as to pass close to its surface, will be partially plane vibrations in the surrounding media, which give rise re polarised, the plane of polarisation being parallel to the spectively to light and sound.

tangent plane to the surface of the body at the point of It appears obvious that as the motion of a molecule of emission. a body as a whole increases—that is, as the temperature In the case of an incandescent gas, the surface molecules rises, the internal motion in the molecule also increases, are continually changed, and as a molecule may arrive at considering that the action of one molecule upon another the surface in any position, and is equally free on all sides, must be due to the mutual action of atoms, or to the all trace of polarisation in this light will be destroyed. interatomic forces, it seems probable that the internal The fact that incandescent metallic plates do emit par. pis viva in a molecule, to which the light is due, is pro- tially plane polarised light in directions nearly grazing the portional to the vis viva of the molecule as a whole, to surface, the plane of polarisation being parallel to the surwhich heat is to be referred. Thus, as the temperature face, and that incandescent gases emit unpolarised light, of a body rises, the internal vis viva in the molecules has been observed by Arago. increases, and the vis viva communicated to the ether As the molecules at or near the surface of solids or also increases ; hence the intensity of the vibration in liquids can cause vibrations in the ether, giving rise to the ether increases, and at the same time the period of emitted light, it is to be expected that, in some cases at vibration diminishes, or waves of shorter length are con- least, it will be possible for light, if of sufficient intensity, tinually produced with increasing intensity,

when incident upon a body, to cause vibrations in the Hence, as the temperature of a body rises, radiant heat atoms constituting the molecules near the surface ; but is given off, the intensity corresponding to a given wave considering the difference of mass of the atoms of the length constantly increasing, at last then vibrations in the body and of thuse of the ether, that the atoms of the body ether, with wave lengths corresponding to the extreme red will vibrate slower than those of the ether, the actual of the spectrum, will be caused with sufficient intensity times of vibration depending, howerer, upon the molecular to be visible, and thus the body will begin at first to glow forces in the body. As these atomic vibrations will again with red light; as the temperature still rises, and vibra- affect the ether, such bodies will or may become luminous, tions of shorter and shorter wave lengths become of the wave lengths of the emitted light being, however, visible intensity, the light emitted will gradually change longer than those of the incident light which causes the from red to white.

disturbance in the body. From Draper's law that all bodies become incandescent This emitted light will necessarily last some time after simultaneously, as well as from other considerations, it the incident light is removed, for the vibrations in the seems probable that in all bodies the internal vis viva in the body will not cease as soon as the cause of disturbance is 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.

emitted light will speedily disappear, though cases may In solid and liquid bodies, the molecules being con- occur in which it will continue for a considerable time. stantly under their mutual actions, and these actions being These probable deductions from the assumed principles subject to constant change from the varying relative posi- coincide exactly with the phenomena of fluorescence and tions of the molecules, the atoms cannot assume any phosphorescence (not including in this term cases in which definite periods of vibration, but are constantly changing light is emitted by bodies undergoing slow combustion), the time of vibration; hence the vibrations in the ether all fluorescent bodies being phosphorescent for times of will be constantly, and with extreme rapidity, changing different, though in all cases at present observed, of very their periods. This change having apparently no limit, short duration, and the effect upon the eye continuing for a finite time, light of all wave lengths will appear to be given off simul

ACADEMY OF SCIENCES. taneously by such bodies when the temperature is suffi. ciently high ; in other words, incandescent solids and

December 4, 1865. liquids will appear to give off white light, which when M. H. ST. CLAIRE DEVILLE read a note On the Hydrauanalysed by a prism will yield a continuous spectrum. licity of Magnesia" of considerable industrial importance.

In the case of an incandescent gas or vapour sufficiently He said that seven years ago M. Donny sent him a speciremoved from a state of saturation to be considered per- men of magnesia prepared by the calcination of the fect, the atoms will be left to vibrate under the action of chloride. Some of this, which was in compact anhydrous the interatomic forces only, and will thus assume periods lumps, he left for several months under a tap in his labora8.3

[ocr errors]

Academy of Sciences.


Dec. 15, 1865. tory, constantly exposed to running water. In this time it rancid to the oil. When the oxidation takes place in a took a remarkable consistence, became hard enough to confined space these acid vapours accumulate, and may scratch marble, and as translucid as alabaster. After six produce bad effects on animals or individuals who years' exposure to the air it has in nowise changed, and its breathe them. Among the vapours will be found formic, analysis gave the following results :

acetic, acrylic, and butyric acids, and probably acroleine. Water.


Most of these arise from the decomposition of glycerine, Carbonic acid

butyric acid alone resulting from the oxidation of the fatty Alumina and oxide of iron


acid. The elastic, resinous, solid matter left after the complete Magnesia


oxidation of linseed oil has, according to the author, a very Sand


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 Thus the substance appears to be essentially a crystallised heat, oxidised linseed oil, M. Cloez tells us, deepens in hydrate of magnesia, like brucite, which does not absorb colours, swells up, gives off a suffocating odour, succinic carbonio acid. To prove that it really was so, M. Deville acid, inflammable hydrocarbons, and in the end leaves a prepared magnesia by calcining the nitrate, powdered it, carbonaceous residue in the retort. Boiling water has made it into a semi-plastic mass, and sealed it in a tube little action on the oxidised oil; alcohol and ether dissolve with some boiled distilled water. After some weeks the out a thick fatty matter, which, among other substances, mass became as hard and compact as the other, and also contains unchanged margaric and oleic acids. M. Cloez crystalline and translucid. After drying in the air this sums up the results of his investigations as follows:-1. mass was found to have the composition HỎ30°7,Mg069-3, All fatty oils, without exception, absorb oxygen from the showing it to be a simple hýdrate of magnesia. With air, and increase in weight. 2. Elevation of temperature similar magnesia the author took casts of medals, as with facilitates the operation. 3. Intensity of light also has a plaster of Paris, and on placing the casts in water found marked influence on the progress of the phenomenon. them to assume the appearance of marble. M. Balard's 4. Light transmitted through coloured glass retards the magnesia-that is, the magnesia prepared by calcining the oxidation. Starting from colourless glass, the retardation chloride obtained by the treatment of sea-water, -calcined is increased by coloured glass in the following order :at a red-heat shows astonishing hydraulic qualities. Cal Blue, violet, red, green, yellow-that is, oil covered with cined at a white-heat for hours its hydraulic qualities are yellow. glass, oxidises most slowly. s. In the dark the in part destroyed. A mixture of chalk or marble and oxidation progresses very slowly. 6. The presence of magnesia forms with water a plastic mass, which after re

various matters accelerate oxidation. 7. In the resinimaining some time in water becomes extremely hard. With fication there is a loss of carbon and hydrogen and an a mixture of equal parts of this magnesia and powdered assimilation of oxygen. 8. The various oils in oxidising marble, the author hopes to make busts which by hydra. furnish the same products ; gaseous and volatile comtion will be converted into artificial marble. A mixture pound acids, unchanged solid and liquid fatty acids, of plaster of Paris and magnesia he finds to break up immediate principle. Oils oxidised in the air no longer

and a solid, insoluble matter, which appears to be a definite under water. The next experiments are of great import. The author finds that a dolomite rich in magnesia

contain glycerine. 9. Lastly, drying oils do not differ when calcined below a dull red-heat and powdered and chemically from the non-siccative oils. made into a paste, forms under water a stone of extra

M. G. Jean sent a note “ On Ozone, and the Splitting up ordinary hardness. M. Deville exhibited to the Academy of Carbonic Acid into Ozonised Oxygen and Carbonic Oxide, specimens he had made with the dolomite used by Messrs. under the influence of Electricity." The author employed Bell, of Newcastle, for making Epsom salts by Mr. Pat an induction coil, provided with a peculiar condenser, for tinson's process. When the dolomite is strongly ignited dividing the spark into an infinite number of very feeble and some quick-lime produced, the mass does not set so sparks. By this apparatus, he says, he proved that car. well, crystals of arragonite separating in thin veins. bonic acid, under the influence of the sparks, split up into When dolomite is heated to bright redness, and all the carbonic oxide and oxygen ; and the odour and other chalk conrerted into quick-lime, the paste formed with it tests showed that the oxygen was strongly ozonised. breaks up in water. All the experiments,

M. Deville states, Atmospheric air exposed to the same influence becomes show that the magnesia is the binding material, which in ozonised, and forms nitric acid (?), which suddenly decombecoming hydrated holds together the particles of chalk poses into nitrous acid when the air is heated. There are or marble to form a compact homogeneous stone. He has some other curious things in the note, from which we exposed some of the stones to the action of the sea in the shall only further quote the account of the properties of port of Boulogne, and they at present remain unaltered. Ozonised oxygen, the author says, has the proThe facts contained in this note proved the perfect hydrau. perty of giving rise to vapours when mixed with sul. licity of pure magnesia by the formation of a definite phurous or nitrous acids, and these vapours are very hydrate.

persistent in the presence of ammonia and iodine. Crystals The experiments with dolomite are of the most import of iodine dropped into a vessel of ozonised oxygen also gives ance to us, and no doubt some of our readers will follow rise to a very thick vapour, which gradually precipitates up the experiments made by the accomplished author of in the form of iodic acid. A coating of linseed oil on this note.

glass exposed to ozonised oxygen became dry in an hour, M. Cloez presented a third memoir “On the Oxidation and its weight was found to have increased by 20 per of Fatty Vegetable Oils.” It contains nothing that the cent. The quautity actually absorbed, the author stated, author has not said before ; but we give a summary. It must have been much more considerable, for it was dis. has been commonly supposed that the presence of albu. engaged in the form of strongly-smelling acid vapours. minoid matter, mucilage, &c., in vegetable oils promote M. Simonin communicated some determinations of the their oxidation. This, M. Cloez assures us, is not the “ Pressure and Temperature of tho Air in Mines." His fact. Oils perfectly free from such matters oxidise as results do not enable him to establish any general laws, rapidly in the air as those contaminated by them. He but the mean of four experiments at the coal mines of then proceeds to show that the resinification of oils is Creuzot and Epinac gave a rise of one degree (C.) of tem. owing to the subtraction of carbon and hydrogen and the perature for every 45 metres of vertical descent ; and a addition of oxygen. Only a part of the carbon disappears rise of one millimetre in the barometer for every 101 metres in the form of carbonic acid, the rest escaping in the acid, of vertical descent. acrid, suffocating vapours which give the odour called An account of “ The Mineral Waters of Atami, Japan,"



[ocr errors][merged small][merged small][merged small]

by M. Lemoyne, was read. The source of these is an again caught by a plant, and now fixed in a grain of wheat ; intermittent spouting hot spring, similar to the Geysers then becoming part of a human organism, to be again cast of Iceland. The temperature of the water the author forth and enter a tree; and in time, reduced to charcoal, found to be 95° C. The composition, as given, shows enter a steel blade, in which stage of existence it witnesses nothing particular, but the examination was necessarily fearful scenes of bloodshed. But " when,” says the atom, incomplete. The water is used (externally) by the “ I speak of these scenes as fearful, I make use of a human Japanese for rheumatic affections and diseases of the skin. expression ; for I need scarcely say that death has no

M. J. Personne sent a note “ On the Decoloration of terror for an undying atom." The atom follows his history lodide of Starch by Heat," in which he admitted the ex- a few stages further, and then concludes :planation of M. Payen to be correct (see page 155), but “Such is the story of my life, or, rather, of a fragment claimed the first publication of the explanation. He of my life. I enjoy perpetual youth. To-day I may be added, however, that the decolouration may be the result buried in a mass of corruption; but to-morrow I may of three different causes :-1. The disappearance of form part of a newly-opened rose. Time cannot reach part of the iodine driven off by the heat; 2, the dis-me; his hour-glass may be shattered and his scythe broken, appearance of another part to form a sort of compound, but still I shall exist. At the present moment I am joined still unknown, with starch, the colourless solution of to countless other atoms, indestructible and eternal like which becomes blue on the addition of chlorine or nitric myself, in a fragment of sugar ; but who can tell where I acid ; and 3, the modification undergone by starch under shall be in a year's time?" the influence of iodine, whereby it is rendered completely We might make almost any number of quotations as soluble, and even converted into glucose.

interesting as that above; but we prefer to commend the M. J. E. Petrequin re-opened the case Ether v. Chloro- entire book to our readers as the best we are acquainted form.” The surgeons in Lyons, he stated, have for fifteen with to give a studious youth. A word of praise must or sixteen years used pure ether as an anæsthetic, to the also be given to Mr. C. H. Bennett for his drawings, entire exclusion of chloroform, with the happiest effects, which are full of humour, and in some cases eminently and no fatalities. He showed that the ill effects some suggestire. times produced by ether always come on gradually, and may be relieved, while chloroform often kills like a lightning stroke. He stated also that with pure rectified ether

NOTICES OF PATENTS. complete anæsthesia is produced in six or seven minutes ; and who, he asked, would endanger the life of a patient to GRANTS OF PROVISIONAL PROTECTION FOR save two or three minutes of time? He concluded a paper

SIX MONTHS. which deserves the serious attention of all surgeons by Communicated by Mr. VAUGHAN, PATENT AGENT, S4, Chancery stating that the object of his ambition was to put a stop to

Lane, W.C. the lamentable martyrology of chloroform.

2892. T. Redwood, Montague Street, Russell Square, M. Velpeau addressed the Academy, and said that he Middlesex, “ Improvements in the preservation of meat had had many thousands of patients under chloroform, and the concentration of its juices.”—Petition recorded and had never lost one by it! 'He thought that ether and Nov. 10, 1865. chloroform might have their respective advantages, and it

2934. J. 1. A. Mallet, Boulevart St. Martin, Paris, would be well to keep both in use.

“A new or improved process for the manufacture of M. Villemin presented a note On the Cause and Nature oxygen."-Nov. 14, 1865. of Tuberculosis," in which he showed that this disease is 2970. G. Taylor and J. Fernie, Leeds, “An improvecommunicable by inoculation. He inoculated some rabbits ment in the manufacture of steel castings."-Nov. 18,1865. with tuberculous matter from the lung of a man who had 3009. T. Redwood, Montague Street, Russell Square, died of phthisis, and in every instance found tubercles in Middlesex, "Improvements in the preservation of animal the lungs of the animal, and often deposits in other parts substances, such improvements being especially useful of the body. The author concludes that tuberculosis is a when these substances are intended for use as food."specific affection, and that its cause resides in an inoculable Nov. 23, 1865, agent. The disease may, therefore, range nosologically by

3025 W. A. Lyttle, General Post Office, London, the side of syphilis, but stands nearer to glanders.

" Improvements in furnaces."—Nov. 25, 1865.

3043. W. R. Lake, Southampton Buildings, Chancery

Lane, " Improvements in the mode of, and means for, NOTICES OF BOOKS.

preserving fruit and other perishable substances.”-A

communication from B. M. Nice, Cleveland, Ohio, U.S.A. The Fairy Tales of Science. A Book for Youth. By J. - Nov. 27, 1865; C. Brough. With sixteen illustrations by C. H. Ben.

3047. Ć. H. Newman, Chertsey. Surrey, “A new kind nett. London: Griffith and Farren. 1866. (Second of unfermented and unintoxicating malt liquor, which edition, revised by the author.)

shall keep sound for any period of time." —Nov. 28, 1865. Ar this season of the year there are always anxious parents ments in the process of treating materials for the manu.

3067. C. S. Baker, Fleet Street, London, “Improveand affectionate friends in search of a book to give to facture of paper and other similar textile fabrics, and in intelligent youths in whose minds they wish to see a love of science spring up. Mr. Brough has furnished apparatus for the same." -- A communication from R. H.

Collyer, Pont An-demer, Eure, France.-Nov. 29, 1865. them with exactly the book they want. It is a book a boy will read with enjoyment, and having read it, will be pretty certain to wish for an extended knowledge of the

CORRESPONDENCE. wondrous things here lightly sketched to stimulate his curiosity. The subjects are very varied, embracing some

The Cosmos" and the Poisoning by Mercuric Melhide. thing of every science; but everything is told in a simple but exciting way. Thus, in “the life of an atom," the

To the Editor of the CHEMICAL NEWS. author makes an atom of carbon tell the story of some of Sir, - Your French correspondent, referring, in your last its migrations through animate and inanimate nature. number, to the recent letters in the Cosmos about the Once, in primitive times, a portion of solid rock, then set poisoning of the two assistants, Dr. C. U—and Mr. T. free by volcanic agency to be seized by a plant and lie C, in the chemical laboratory at St. Bartholomew's buried for ages, until again brought to the surface in the Hospital, has given a very extraordinary misrepresentation form of coal, only to be once more dissipated in air and of the facts, which I can hardly attribute to his imperfect CHEMICAL NEwa, 290 Miscellaneous-Answers to Correspondents.

Dec. 15, 1866. knowledge of the French language. In my usual English ganese the more will the sulphur be retained in the burned Correspondence" in the Cosmos, I stated that this sad precipitate, and with some varieties not more than ten affair occurred under the direction of Dr. Frankland, who cwt. of sulphur could be obtained from two tons of prewas Professor at the Hospital, a mistake corrected cipitate. immediately. I am, &c.

In adopting any new process, I consider that the most T. L. Phipson, Ph.D., F.C.S.,

adverse facts should be looked full in the face; and I only One of the Editors of the Cosmos. point out these drawbacks not to deter any one from London, December 9.

adopting it, but simply that the process should be estimated [We insert the part of Dr. Phipson's letter which concerns at its real worth. our correspondent, but must decline to make the

It would be strange, indeed, if I would deliberately conCHEMICAL News a vehicle for other recriminations. demn without reason a process which I laboured so mueh

at to perfect. As it stands, it is only a partial success. At ED. C. N.]

least one-third of the sulphur is lost after being precipitated,

and the residue is absolutely worthless unless some use can Associate of the Royal School of Mines.

be made of sulphate of manganese. To the Editor of the CHEMICAL News.

I would suggest as an improvement on M. Kopp's proSIR.-In reply to the inquiry made by Mr. Denham Smith posed arrangement of processes that the manganese should in your last number, I desire to inform your readers that not be precipated at all, but that the process should be the title of " Associate of the Royal School of Mines" is conducted in accordance with the second proposition in granted under conditions sanctioned by the Lords of the Townsend and Walker's patent, adding M. Kopp's proCommittee of Council on Education and by their authority: posal to utilise the sulphuretted hydrogen. By this means The certificates of Associateship are signed by the Lord obtained, and all the sulphur would be recoverable as sulPresident.

I am, &c.

phurous acid, leaving very little residue. Royal School of Mines, December 6.

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. Köpp's Utilisation of Soda Waste and Chlorine Residues.

labours in the same direction; and if M. Kopp knew and To the Editor of the CHEMICAL NEWS.

published all the facts as they stand described by us before SIR,—On reading M. Kopp's last letter, in No. 313 of the that time, he is then entitled to claim priority, CHEMICAL News, I am particularly struck with the coin

I am, &c. JAS. WALKER. cidence of his results with my own experiments. As a

275, St. George's Road, Glasgow, Dec, 11. labourer in the same field, it gives me much pleasure in confirming his figures.

MISCELLANEOUS. His plan of oxidising the alkali waste is very simple and ingenious, and I would also expect that it will work effec- Chemical Society. The next meeting of this tually. I see, however, that M. Korp still remains under Society will take place on Thursday evening next, at the impression that his process is quite original, and that 8 o'clock, when a paper, by Mr. J. Yates, will be read, it has not been patented in England. To correct this, On the Material for Mural Standards of Length.” allow me to refer him to Townsend and Walker's patent, No. 3038, dated 11th December, 1860. He will find

Royal Institution of Great Britain. The folthere the identical process which he now describes, and lowing are the lecture arrangements for the ensuing from which permit me to give a brief quotation :

season :--Christmas Lectures, 1865, adapted to a juvenile "First, the solutions (sulphide of calcium and still auditory.-Prof. Tyndall, F.R.S., six lectures “On Sound." liquor) may be mixed in such proportions that the result. Before Easter, 1866:--Prof. Tyndall, F.R.S., twelve lecing precipitate will consist chiefly of sulphur.

tures “On Heat;" Prof. Frankland, F.R.S., eight lec“ Second, the solutions may be so proportioned that the

“On Chemistry;" Prof. R. Westmacott, R.A., resulting precipitate will consist chiefly of free sulphur F.R.S., six lectures “On the Way to Observe in Fine and sulphide of iron.

Arts ; Rev. G. Henslow, four lectures “On Structural precipitate will consist of free sulphur, sulphide of iron, Frankland, F.R.S., four lectures “On Chemistry;" G. “Third, the solutions may be so proportioned that the and Systematic Botany, considered with reference to

After Easter.-Prof. and sulphide of manganese."

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

, Gallery, three lectures " On National Portraits ;" Rev. as M. Kopp has supposed.

C. Kingsley, M.A., two lectures “On Science and SuperThe composition of the precipitates obtained as above stition;" Prof. Huxley, F.R.S., twelve lectures “ On the tallies closely with that given by M. Kopp; the first gives Ansted, F.R.S., five lectures "On the Application of Phy:

Physiological Methods and Results of Ethnology;" Prof. 20 per cent. sulphur, the second

70, and the third
45 to 50. sical Geography and Geology to the Fine

Arts ;
It is in dealing with the third precipitate that the stum-
bling-block occurs which I referred to in my last letter ;

course may possibly be given by Dr. Du Bois Reymond and I can assure M. Kopp that many were the resolute

« On Electric Fish.' attempts to remove it, but all in vain. There it stands still, as ugly as ever, and the figures given by M. Kopp ANSWERS TO CORRESPONDENTS. establish this beyond a doubt.

He commences with a precipitate containing 50 per cent. Dr. Muspratt. - Next week. sulphur, which he calls a sulphuretted sulphuret of man

B. Osborne.-The proportions are given in Dr. Stenhouse's patent ganese

; but I look upon it as simply a mixture of sulphur, specification. Boddodell is used to the extent Dr. Calvert says: sulphide of iron, and sulphide of manganese. From two H. R.-There is a French book on the subject of pyrotechny; but tons of such a precipitate he obtains 14 to 16 cwt. of

we know of no separate work in English on the subject that is not sulphur, in the form of sulphurous acid ; the other 4 to 6 "Technology" has an excellent article on fireworks.

The last volume published of Knapp and Richardson's cwt. remains combined with the manganese in the form of Clericus. -Aniline black is formed on the material dyed purple by sulphate. This may be looked upon as the most favour treating the fabric with a dilute solution of blchromate of potassium able results which could be obtained, as it will vary with or according to Lanth'a process. Sec CHEMICAL Nows, vol. 21., p. 6s. the description of manganese ore used; the purer-the man. Received. -John Clif; a. G. Anderson, next wook.


an extra

very old.

[ocr errors]





[ocr errors]


Researches on the Volatile Hydrocarbons. Dec. 22, 1865.


immediately at 97; The distillation occupied an hour

and ten minutes, during which time the thermometer CHEMISTRY,

rose only 0.6°, being fifty minutes in rising o'zo from

79-4° to 79•6o, at which temperature it had distilled Researches on the Volatile Hydrocarbons, nearly to dryness. Height of the barometer during the by C. M. WARREN.

experiment reduced to o° = 7619 mm. Taking 79'4°; (Continued from page 280.)

this being the average of the last five observations, and On commencing the account of his own researches, the applying the corrections for the upper colamn of 'merauthor first mentions the source of the naphtha used in the cury, and for atmospheric pressure, according to the diexperiments. It was obtained from various American rections given by Kopp, we find the corrected boiling gas works in which, however, cannel and Newcastle point of benzole to be 80'1o. caking-coal were chiefly employed. In some a Pennsyl- Analysis.-(In most cases we abridge the details of vanian caking.coal was also used. The coals were em- the determinations) oʻ2339 of benzole gave by combusployed in the same proportions as in England. The tion in a stream of oxygen gas 0·7903 of carbonic acid, process for purifying the naphtha was the same as that and o:1683 of water. in use here-namely, treatment with oil of vitriol and


Found. alkali, and subsequent rectification and fractionation. Very large quantities were operated upon to ensure the


92'31 92'15 detection of any constituent which might be present in

Hydrogen : #

7'69 799 small proportion. The process of fractioning was continued on the large scale until the separations had so far


100*14 Density of vapour found

2'688 progressed that at certain temperatures a full barrel of distillate would come off from the ten barrel still em

Theory C,H6 = 4 volumes . 2.698 ployed without a variation of more than one or two II. Tolaole. Sp. gr. 0-8824 at oo and 0.872 at 15". degrees of the thermometer. Finally, a sample gallon The preparation used for determining the boiling point was taken from each of the barrels composing the last was repeatedly boiled with sodium. The experiment was series of products, and then set aside for the laboratory conducted as with the benzole... Operating upon a coninvestigations.

siderable quantity the distillation occupied about an In the laboratory the fractionings were made by the hour. It commenced at 110:6°; two minutes later the author's process of fractional condensation described temperature had fallen to 110'4o, at which point it reante p. 85.

mained absolutely constant for forty-eight minutes. Five They were continued until the whole of the naphtha minutes later the temperature had risen again to 110.6°, taken, boiling between 80° and 170°, had accumulated at and five minutes later to 110.8°, at which point the the four points indicated—viz., at 80°, 110°, 140°, and operation was suspended. The corrections made as in 170°, or so nearly the whole that the intermediate quan- the case of benzole gives 110'3° as the corrected boiling tities had become too small to admit of being further point of toluole.

Church remarks that toluole when operated upon. Having so thoroughly exhausted the distilled in the ordinary manner is liable to become oxiintermediate fractions, Mr. Warren says, I can have no dised, and its boiling point thereby raised in consequence hesitation in asserting that no other body than those of the upper part of the retort becoming heated above alluded to was present in the naphtha—at least, in appre- the boiling-point of toluole. He found that the toluole ciable quantity-hence that the parabenzole of Church which by ordinary distillation had come over between was probably only a mixture of benzole and toluole. 1089 and 109° would distil eight tenths between 103° On some Properties of the Bodies obtained by

and 104", after repeated rectification with sodium. I Fractioning.

would therefore state that my preparation of toluole was

never subjected to a higher temperature than its boiling 1. Benzole.-Sp. gr. 0.8957 at oo, and 0-882 at 1595° point; and that I have never noticed any reduction of The experiment to determine the boiling point was con- the boiling point of this body by purification with ducted in a tubulated retort, operating on 150-200 c.c. sodium. of the benzole, containing some pieces of sodium. The

Analysis.--0-1628 grm. of toluole by combustion in a benzole employed had previously been repeatedly boiled stream of oxygen gave 0.5447 of carbonic acid and 0:2315 with sodium until the latter ceased to have any action. of water. The thermometer bulb extended into the liquidt nearly to


Found. the bottom of the retort. A second thermometer was attached by means of flexible bands to the side of the Carbon


91'3 91020 one in the retort; the bulb being placed during the ebul- Hydrogen

8 87 8.97 lition at a point midway between the centre of the cork (-5°) and the upper end of the mercurial column


100'17 -viz., at 35o. A paper screen closely fitting the ther

Density of vapour found . 3'2196 mometer spindle was placed across at the top of the

Theory CH3=4 volumes

3:1822 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. oʻ178 at oo 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. Abridged from the Memoirs of the American Academy,

Taking the average-viz., 138.4°, and making customary * The author has somo critical remarks on the propriety of placing corrections, we find 139.8° to be the corrected boiling the bulb in tho liquid, which we shall give on a future occasion.

point of xylole. VOL. XII. No. 316. DECEMBER 22, 1865.

[ocr errors]


« PoprzedniaDalej »