Obrazy na stronie


MiscellaneousAnswers to Correspondents.

{ ,

July 7, 1865.

the last portions of the milk away. The pounding and indicated a higher degree of hardness after boiling than the washing only occupy two minutes, and, as your before, Nearly twelve months ago I was requested by a readers will see, the butter is made with less lalour than client to examine a water with reference to its applicability in any churn yet invented. In the winter, when the to ordinary domestic purposes; and after examining it ground is frozen, the cream is buried in sand placed for microscopically, as well as estimating the amounts of the purpose in cellars, and a double bag is sometimes organic and inorganic matter which it contained, one of employed to make sure of getting no sand or earth into my assistants endeavoured to determine its hardness, which, the butter.

to his astonishment and to my own, was increased instead I should have told you some time ago of a trial here of diminished by boiling. Concluding that some mistake which will have some interest for English pharmaceutical must have been made, the experiments were repeated, readers. MM. Grimault and Co. import pepsine from both by my assistant and by myself; but we always London, and retail it as pure English pepsine. Some obtained the same anomalous result, no matter whether thing, however, trade and professional jealousy, it is the water was boiled for an hour or for a whole day. alleged-caused a quantity of it to be seized by the police, Several fresh preparations of soap-test were made with and it was examined by M. Roussin, who reported that soap from different sources; sometimes the soap was disthe pure English pepsine was nothing but starch, and solved in vinic alcohol, at others in methylated spirit. MM. Grimault and Co. were accordingly condemned. The various preparations of soap-test were graduated with That happened some months ago, but the affair has re- solutions of chloride of calcium made and standardised at cently come before the courts again in the shape of an three different periods. Having taken these precautions to appeal by the defendants, and MM. Payen and Beaudoin eliminate any error which might have been introduced into have now examined the pepsine, and these gentlemen the previous experiments through the reagents employed, report it of good quality. M. Leconte also examined and the attempt to ascertain the hardness of the water by reported favourably; but the Court, apparently not alto- means of the freshly and differently prepared soap-test gether satisfied, has ordered a fresh examination of the was resumed. Still, it was observed that ebullition invari. pepsine seized and other pepsine from London by MM. ably caused an increase and not a diminution of the hardFremy, Mailhe, and Reveil, and after they have reported ness of the water. Unfortunately, I am unable at present the Court will give judgment.

to furnish a more detailed account of the experiments Some experiments have recently been made by M. above referred to, as the notes taken at the time of their Tresca on Poissant's process for decorticating wheat before being instituted are in the possession of my assistant, who it is ground into flour. The corn is first slightly inoistened, is in Marburg. I trust, however, soon to receive the notes, and then conveyed to a cylinder in which a sort of fan and to be able to procure a fresh supply of the water to revolves with great rapidity. By this action the outer which they refer, in the hope that the results of a minute skin of the grain is detached, and is subsequently sepa- analysis will enable me to explain an anomaly which rated by winnowing. The flour is reported upon by M. appears at present to be as inexplicable to Dr. Voelcker as Payen, who says that 100 of dry corn gives 89.6 of flour, to myself.

I am, &c. which contains a considerably larger amount of nitro.

RICHARD V. Tusox. genised principles, and is therefore more nutritious, than Chemical Laboratory, Royal Veterinary College, June 28. ordinary flour, but which will not make bread so white. He considers the flour will succeed well with Dauglish's

MISCELLANEOUS. process. Writing of corn reminds me of the prospects of harvest,

Non-Explosive Gunpowder.— The invention of and may be it will interest some of your readers to know Mr. Gale, which we mentioned last week, underwent that colza and linseed have failed nearly everywhere in

a trial at Plymouth last week in the presence of several this country this year.

naval and military officers, and it was shown that the I extract some statistics on the subject of deaths by powder, when treated by Mr. Gale's process, could not be lightning from a note by M. Boudin. the period 1835-1863, 2238 individuals were killed in ignited by an ordinary slow match, or even by a red-hot

The invention at first sight would appear exFrance. The most in one year was 111; the fewest, 48. tremely valuable, but soldiers and sailors, we expect, will Among the 880 persons killed from 1854 to 1863, only be startled at the idea of going into action with non-ex243 were females, which will be 26'7 per cent. land the proportion of females killed 'is only 21:6 per cent. plosive gunpowder, although the explosiveness can be In many cases, M. Boudin says, when the lightning has easily restored in two minutes.

Destruction of scientific Property. by Fire. fallen upon a group of people

of both sexes, it has only On Thursday last a most calamitous fire destroyed over killed the males and spared the females, which, I must 30,000l. worth of literary and scientific property at the say, is more gallant than fair on the part of the lightning. well known Auction-rooms of Messrs. Sotheby and As a set-off to this conduct, I suppose, the fluid, when it has fallen upon a flock attended by shepherds, has only valuable collection of photographic lenses, magic lantern

Wilkinson. We are, however, happy to state that the killed the sheep and spared the shepherds. M. Boudin states that there have been many instances of beeches slides, and the greater part of the other apparatus anstruck with lightning, and that there are at least two having, at the time of the fire, been in the care of Mt.

nounced for sale in our advertising columns, is saved, examples of individuals struck more than once in the course Highley, at 18, Green-street

, Leicester-square. The sale of their lives; one man, indeed, was struck three times in will take place on Tuesday next, as originally fixed, but as many different parts of his body, and another man was struck twice in his left foot. The statistics, I may add,

at the gallery, 21, Wellington-street. prove the danger of standing under trees in a storm.

ANSWERS TO CORRESPONDENTS. On Anomalous Degrees of Water Hardness. To the Editor of the CHEMICAL NEWS.

Received -Oxamide; Report of Manchester Scientific Students'

Association for 1864. SIR.-In consequence of niy not having been present at A Constant Reader writes :-"I saw lately, but cannot lay my bands the Chemical Society when Dr. Miller read his paper on

on it, an artificial, quick modo of disintegrating the leguminous

portion of leaves, and retaining the woody i r fibrous portion as a “ Potable Waters," I shall feel obliged by your inserting skeleton. Can you or one of your numerous readers furnish me with in your journal the following remarks corroborative of the an efficient process ? Also, a cotton yarn ‘plated' or coated with silk novel and interesting statement made during discussion by (by a process analogous to plating) was, and probably is now, used in

glove manufacturing (also lace), evidently not coated from an etherial Dr. Voelcker, to the effect that he had analysed a water which I solution. Can you inform me the proceso ?"

CHEMICAL NEWS, On the Volumetric Analysis of Superphosphate of Lime.

13 July 14, 1865. SCIENTIFIC

the time occupied from first to last is barely one-fourth AND ANALYTICAL

of that required by the ordinary gravimetrical method. CHEMISTRY.

June 27.







On a Volumetric Analysis of Superphosphate of Lime,

On the Easily Fusible Alloys of Cadmium, by by GEORGE JONES, F.C.S.

CARL RITTER VON HAUER." It has for some time been a desideratum of analytical The alloys were made by fusing the ingredients in a agricultural chemists, and especially of those connected covered porcelain crucible at the lowest possible tempe. with the manufacture of artificial manures, to be enabled rature. *After stirring with a glass rod, the fused mass by a more speedy method than the one generally pur- was poured upon a cold metal plate, where it instantly sued to arrive at a correct estimation of the amount of solidified. The specific gravity and the melting point phosphate of lime existing in a soluble state in the so- were determined after the alloy had been so melted and called " superphosphate.". I have therefore been led to cooled two or three times. In the two or three fusions attempt a series of experiments upon a process of volu- a partial oxidation of the metals takes place, which occametric estimation, by the use of a standard solution of sions a slight alteration in the equivalent proportions, ammonia ; but at the onset I experienced some difficulty and which it is almost impossible to avoid. The melting in arriving at any satisfactory result in consequence of point was determined under hot water, and also by the existence of the free or uncombined sulphuric acid, placing a thermometer in the fused mass without water. which is invariably present in ordinary commercial super. Under water the alloys quickly oxidise. They have also pliosphate, it being impossible to present an alkali the property of becoming pasty below their proper meltwithout precipitating the phosphate of lime.

ing point, which may lead to error in the determinations. The process I therefore adopt is the following: The author's determinations were made when the alloy Having taken 100 grains of the sample for analysis, it was really fluid. is first of all well mixed with about so grains of finely The specific gravity of the metals experimented with powdered litharge, and introduced along with a small quantity of distilled water into a flask, and boiled for for the calculation of the proportions

were as under ; the equivalent. numbers are also given about fifteen minutes. The whole is then made up with

Cadmium distilled water to 7000 grains (one deci-gallon), agitated

56 Tin

76265 58 well, and thrown upon a filter. I then take of the filtrate,


11'350 1037 by the use of a pipette, 1400 grains (200 septems) equal


9'708 to 20 grains of the sample, and add thereto a little chlo

Equivalent propor- Specific gravity.


Molting ride of calcium solution, and 200 septems of the standard

Found, Calculated.

point. solution of ammonia; it is then made up with distilled Cd Sn Pb Bi 9765


+0.141 68.5°C water to a known bulk-say 2000 grains, agitated well, Cd Sn, Pb, Bi, 9.784

to'o86 68.5°C and filtered.

Cu, Sn, Pb, Bi( 9725


67.5°C A 1000 grains pipette of the filtrate will therefore Cd, Sn, Pb; Bi; 9.685

+0'033 65.5°C représent exactly 10 grains of the sample, and in this I The above shows that some contraction of the metals now proceed to test for emmonia, added over and above takes place, but the smallest contraction is combined that required to separate the phosphate of lime in the with the lowest melting point. sample. Two equivalents of ammonia being required Lipowitz states that an alloy composed of three parts for every equivalent of the tribasic phosphate of lime by weight of Cd, 45n, 8Pb, and 15 Bi melts at 60° C.; precipitated. Thus

but the author of this paper observes that such a comCaO, POs, + 2 CaCl + 2NII,O=(Cao),PO, and 2NH,ci. pound only becomes perfectly fluid at 70° C. The standard solution of ammonia I am in the habit

The melting point of an alloy of two parts Cd, 3.Sn, of using contains in every septem 'or of real ammonia, 11Pb, and 16 Bi is still higher-namely, 76° C. and I employ also a standard solution of hydrochloric

The following mixtures had the same melting pointacid, 50 septems of which require 292 of the standard One part by weight of Cd, 2Sn, 3Bi ammonia for neutralisation.

Two parts

Cd, 3Sn, 5Bi perfectly fluidat95°C. In order, therefore, to estimate the excess of ammonia

One part

Cd, Sn, 2Bi added to the liquid, I first add 50 septems of the standard

The author adds the following determinations of speacid, and then test with the standard ammonia, using, of cific gravities and melting points :

Specific gravity,


Proportions. course, a solution of litmus. Supposing, therefore, that

Found. Calculated.

point. 255 measures or septems of the standard ammonia are

1 part Cd, 6Pb, 7Bi 10'529 10-330 +0'199

88°C required to effect a complete neutralisation of the liquid,

Cd, Bi2, Pbg 10'563 10'275

+0.288 89.5°C then say-292 - 255 = 37, and 100 (the number of mca

Cd2, Big, Pbz 10*732 10'341 +0.391

95°C sures previously added).- 37 = 63 measures of standard ammonia required to precipitate the phosphate of lime, and equal to 6'3 per cent. of real ammonia.

Synthesis of Formic Acid. Therefore as

Dr. R. MALY shows that formic acid is obtained under 2(NH)(CaO),PO, per cent.

various circumstances when nascent hydrogen and car34 :

:: 6'3 : to x = 28672 p.c. of phosphate bonic acid at the moment it is set free, come together in

of lime. By the use of the oxide of lead, the free sulphuric acid for example, is procured when sodium amalgam acts on

the presence of a powerful base. A large proportion, of the sample is not only neutralised but separated as

a solution of carbonate of ammonia. The acid is also insoluble sulphate, leaving the solution but slightly acid, found, but in smaller proportion, when finely granulated and only from the acid phosphate. By repeated trials ppon samples of known composition, I have never found zinc, carbonate of zinc, and caustic potash are boiled this process to fail. It is both simple and accurate, and # Abstract from Journal für Prakt. Chemie, vol. 94, p. 436.

YOL. XII. No, 293:-JULY 14, 1865.


The Dublin International Exhibition.


July 14, 1865. together, in which case the nascent hydrogen simply causing the eyes to water, and which hare already been seizes upon the carbonate of potash

obtained in the oxidation of alcohol and ether by GO,+H2+KHO=CHKE,+H,0.

platinum black. This black, under other conditions, The first reaction is, perhaps, capable of general appli- will give acetic acid, and here between platinum black cation for the preparation of homologues of formic acid, and mycoderma vini there is a resemblance of effects if, instead of carbonate of ammonia, the carbonates of from which it would be unsafe to infer a resemblance of methylamine or ethylamine, &c., are employed.—Journal causes. The only inference to be drawn is that both are fur Prakt. Chemie, vol. 94, p. 442.

means of transporting the oxygen of the air on to certain combustible matters.

For the production of acetification it is necessary that Researches on Acetic Fermentation, * by M. PASTEUR.

the mycoderm should be at the surface of the liquid ;

the process is arrested by submersion, and only reconsIt is a well known fact that wine, beer, and cider ex

mences on the formation of a fresh film on the surface. posed to the air turn sour, and it was long since proved that this phenomenon was due to the alcohol of these and not a trace of this gas enters the liquid through it.

The absorption of oxygen by this film is complete, liquids being transformed into acetic acid; but what when there is, as in Orleans' vinegar, a large quantity part does the air play in this combustion, through of small eels-animalculi needing air to support life-a what intermediary state of transformation does the curious contest takes place between them and the mycoalcohol pass ?

derin, the latter tending to engross the whole of the Acetic fermentation is always produced by the exclu- surface, while the former combine all their efforts to sive influence of an organism-The mycoderma acetione of the most simple vegetables, consisting essentially submerge it and expose the liquid in which they live to

free contact with the air. of frames of articulations slightly compressed towards the middle, measuring about oth of a millimetre in ment acts and of the last interesting particulars will,

The complete study of the manner in which this ferdiameter, and double that in length. However much perhaps, cause some progress to be made in the induscharged with albuminoid matter, no alcoholic liquid has trial preparation of vinegar ; but the study of possible ever been known to give the appearance of acetification improvements must be left to the manufacturers. without the presence of this mycoderm. On the contrary, if a trace of the mycoderm is spread on the surface of an albuminoid liquid, alcoholic or slightly acid, it is immediately seen to develope, extend like a veil

DUBLIN INTERNATIONAL EXHIBITION. over the surface, and by a correlative action the atmospheric oxygen in contact with the liquid disappears and By CHAS. R. C. TICHBORNE, F.C.S., F.R.G.S.I., &c. the alcohol acetifies. It is not essential for the liquid to

(Specially Reported for the CHEMICAL SEWs.) contain albuminoid matters ; provided the mycoderm

(Continued from page 6.) finds there besides the alcohol a small quantity of alka. Two complaints have been forwarded to the writer that line and earthy phosphates, it will live and its action be he has passed over, in silence, cases in the Exhibition the same as before ; and this identity proves that the which deserved notice. The writer acknowledges, in a albuminoids which have been employed were merely degree, the justice of the complaints, but then it must nourishment for the ferment, and not the ferment itself. be taken into consideration that it would be perfectly

If in the actual process of vinegar making, acetifica- impossible to enter into particulars of every case tion takes place without the previous spreading of the exhibited in a limited number of articles. Nor would mycoderm, it must have been without the knowledge such articles possess interest for the readers of this of the experimenter; it is this organism which forms journal. The plan followed out has been to dwell upon the gelatinous mass which was formerly, with a vague exhibitors who would best represent a class, also to idea of the truth, called mother of vinegar; it is this notice anything new which might occur amongst the which by spreading over large surfaces of the beech-others. It has been the endeavour of the author, as far wood chips used in the German process produces as possible, not to touch upon a beaten track, but to place acetification. By pouring an alcoholic liquid on these before the readers any little norelties which have been chips, well washed and scoured, and thus deprived of the brought forward by this Exhibition, and will, therefore, ferment, no trace of vinegar is obtained; but, the cir- not be found in any other report. At the conclusion a cumstances being favourable, acetification is produced by complete list of the chemical exhibitors will be given, this depositing a little of the mycoderm on the surface of the being all that space will permit. chips, where it rapidly developes. While alcohol is present the small vegetable produces

Perfumery. - The perfumery department is well acetic acid ; but what happens if the alcohol is wanting? represented by Piesse anà Lubin, Rimmel

, and other M. Pasteur shows that the vegetable can in this case

well-known firms. The first-named house shows some bring its burning action to bear on the acetic acid itself, very novel scents, but scents are so much a matter of and reduce it to the state of water and carbonic acid taste that, to carry out Dr. Piesse's theory, what one This effect seems to be produced only when no alcohol is person may consider a very recherché odour another may present, when there is alcohol the combustion is effected consider a regular flat 7th unresolved, but he may easily by preference on it.

resolve the discordant feeling by turning to one which Such is the action of the mycoderm under the ordinary accords with his ideas. Dr. Piesse has many novel ideas conditions ; but it sometimes alters, and having

no longer upon the subject

of perfumery, and one of the most imthe same appearance or the same consistence, its action portant of them he submitted to the Royal Horticultural is different. It is then incapable of effecting the com- Society some short time since. The commercial importbustion of the alcohol to the acetic stage, and gives ance of the cultivation of flowers for perfumery may be intermediary products with a suffocating' odour, and inferred from the following statistics :- The entire pro

cess of growing flowers for the process of enfleurage is * Annales de l'Ecole Normale, i.

carried on in the valley of the Var, in the extreme south


July 14, 1865.

The Dublin International Exhibition.


of France, bordering upon Italy—that is to say, from purpose there are placed in the horizontal presses between Nice to Cannes and rising to Grassa. This area com- each pair of paraffin cakes hollow plates, through which prises about 115,200 acres. All flowers, the olive and water of 32°- 40° C. is made to flow. In this way

the the vine, thrive here to perfection. The flower harvest hydrocarbons in question are fused and squeezed out. of the district of Cannes alone gives the following The pressed paraffine is now heated to 150° C. either annual supply :-Orange blossoms, 1,475,000 lbs.; roses, over å fire or by means of steam, and the melted mass 530,000 168.; jasmine, 100,000 lbs ; violets, 75,000 lbs. ; is mixed with 2 per cent. of concentrated sulphuric acid, tuberose, 24,000 lbs. ; jonquils, 5000 lbs. This does not by means of which all the hydrocarbons not being include Nice and other districts. The value of these paraffine are carbonised. It is then carefully washed flowers is from ad. to 28. per pound. Now, says Dr. with hot water, and after cooling is mixed with the best Piesse, no tree is so profitable to the flower farmer as the colourless photogen (light mineral oil), and introduced orange, and emigrants to any of our warm colonies into iron jacket cylinders, in which it can be kept warm, should make a note of this, and fix on their memory and where it is filtered through animal charcoal. By that the leaves of the orange yield an otto worth 38. an treatment with superheated steam the photogen is again ounce, that the flowers field an otto worth 1os. an. completely separated from the paraffine. The paraffine ounce, that the blossom also yields by enfleurage a fat manufactured in this manner is said not to bend when worth 8s. per pound, that the rind of the fruit yields an exposed to a temperature of 30° C. otto worth 128. to 16s. per pound. There is a fine In spite of the care expended upon the purification of orangery near Sydney, the property of Richard Hill, paraffine, it is rarely that two samples can be procured Esq., so that we may soon expect in the markets of so as to have a constant melting point. In many of the Britain the produce of this plant from one of our cases beautiful specimens of coloured paraffine candles colonies. Queensland, Western Australia, Southern are shown, and we believe that the coal-tar colours have New Zealand, and Jamaica may take the hint, according been used for this purpose. It has lately been pointed to Dr. Piesse.

out that the fatty acids form salts with rosaniline of a There is nothing new in the way of artificial flavouring intense tinctorial power. We can well understand that essences. A few specimens of essence of pine (butyric these fatty salts would be applicable to the colouring of æther), jargonelle pears (acetate of oxide of amgl). candles, palmitic, stearic, and oleic acids form salts with

Paraffine, Wax, Illuminating Oil, &c.—There rosaniline, and the writer has verified the reaction with are certain names which are intimately connected with chrysaniline. He has no doubt that all the colours specialities. We find two such, represented by two of could be used for this purpose by varying the maniputhe finest cases in the Exhibition; placed one each side lations. From the small quantity requisite, and the of the nave, they stand like another Gog and Magog. organic nature of the pigments, the advantage in refer.

Parafline is now extensively manufactured, and the ence to its non-interference with the illuminating effects process of palm oil distillation will soon be equally dis- must be evident. The pigments in ordinary usc-viz., seminated." But Mr. Young's name is so associated with verdigris, vermillion, chrome yellow, &c., are certainly the former, and Price's with the latter, that one cannot not very desirable in this respect. pass over their cases without paying a passing tribute. In connexion with the present case, we must mention

Paraffine has teen practically separated from resin, the interesting case of Messrs. J. and C. Field, of Lampetroleum, fossil oils, peat, and coal. The last two have beth, one of the original manufacturers of parafine been the most prolific source of this beautiful product, candles. They also invented the self-fitting candles. whilst Mr. Young, by his slow process of distillation But a still more important inrention seems to have direct from coal, has certainly brought the method of originated with them-viz., the plaited wicks, which are manufacturing., paraffine to the greatest perfection. now universally used throughout the world. The wellWhen the Exhibition opened Mr. Young's case contained known night-lights seem to have been their invention, magnificent specimens of castings in paraffine. These the first of them being made of wax. As this is essenincluded a colossal bust of Sir Walter Scott and sundry tially an age of art, we are not surprised to find that even statuettes. Now, these strikingly illustrate the applica- candles are made to bear designs upon their surfacebility of this “solid gas," as Liebig calls it, to the mould- although they are things like Howers, made only to look ing of candles, the contraction of the inelted paraffine gay for a brief space. Some of them, though most gaudy, being comparatively very slight, but sufficient to make are wanting in taste; but, on the other hand, there is a it leave the moulds efficiently. It is, in fact, more suited style of decoration, generally in the floral way, and to this kind of work than even spermaceti

, wax, or painted in very subdued tones, which is beautiful in the stearine. There can be no doubt that before long the extreme. The paraffine is particularly suited for this paraffine will be the candle par excellence. Its beautiful kind of decoration, as it presents such a pure translucent appearance, clear light, and cleanliness will no doubt in background to the colours. There are some rery fine time establish its value. A strange result was produced specimens exhibited by Messrs. Taylor and Co., Leith, in Mr. Young's case during the late fine weather. The and Rathborne and Co., Dublin ; the latter firm being, sun's rays were so strong that most of the figures were we believe, the only manufacturers of paraffine candles partiallý melted, and found on one occasion in anything in Ireland. The process by which this effect is produced but a perpendicular position. This will give us a decided is simply a matter of transferring the painting, which impression of the temperature of such buildings on a is first executed upon rice paper in gum and colours, fine day, when we take into consideration the fact that to the surface of the candle. Messrs. Rathborne pure paraffine melts at 60° C., according to Dr. Hofmann's and Co. are also bleachers of wax, and exhibit a report. This was procured by the following process, specimen of pure wax, This article, it is almost need. which is the one ordinarily used :—The mass of crude less to say, would be almost unsaleable as a commercial paraffine is subjected to hydraulic pressure, first in the product in the present day. The ordinary white wax cold and afterwards with the application of heat. The always contains spermaceti, or some other substance object of this last operation is to remove all hydrocarbons which gives it its white translucent appearance. having a lower melting point than 40° C. For this We think we are right in stating that Price's Patent 16

On the Present State of the Chemistry of Gas Lighting.


July 14, 1865.



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Candle Company at one time worked Rangoon naphtha Ethyl, C.Hz; Propyl, CoH; ; Butyl, C,H, ; Amyl, for paraffine ; but what they are more celebrated C1811, &c. for is their process of distilling palm and other oil by In the third series, which are the chief constituents of which that substance is split up into its components, coal gas, the Olefiant gas series, the proportions of carbon glycerine and the fatty acids, the latter being used in and hydrogen are equal, thus : Methylene, C,H,; their candles. It was this firm that placed pure glycerine Ethylene, CK; Propylene, CoHg; Butylene, C H3; within the reach of the commercial public; and we will Amylene, C1.H10; Capryolene, C11 2. &c. even go further, and say that, until they produced it,

In the next compound, Acetylene C,H2, it is two prothat substance was unknown. It is really wonderful to portions less; and in the Benzol series it is six proporfind the number

of useful manufactures to which it has tions less, thus: Benzol, C.H; Toluol, C14Hs ; Xylol, been since applied.

And, lastly, in the Napthalin series it is at least twelve Lately distilled glycerine has been found in the market proportions less. at various prices, some of it very good, and some equally 2. We notice that the illuminating power of these bad. A German specimen which has come into the hydrocarbons rises in proportion to the amount of carbon possession of the writer has evidently been decolorised contained in a given volume of them-marsh gas being with chlorine. For most of the applications of glycerine the weakest and naphthalin the strongest. this would be very undesirable, whilst very few samples 3. We perceive that their weight, or specific gravity, will be found to have the specific gravity of Price's. rises with their photometrical value-marsh gas being only

Sp. gr. at 60° F. about half as heavy as atmospheric air (0.5531), and Price's glycerine, concentrated upon a

naphthalin four and a-half times (4:42); so that, if water bath.

1'256 accidental impurities were not present in coal gas, the Price's glycerine, as met with in com

specific gravity of it would furnish a good indication of 1'253

its quality German glycerine, very firm and fine

4: We remark that all the richer hydrocarbons, exceptspecimen


ing acetylene and naphthalin, are easily decomposed by Common German glycerine


heat, carbon being deposited, and a weaker quality of gas English plaister glycerine

-generally marsh gas-produced. It is manifest, theregravity into consideration in connexion with the price. the practical conclusion from it is that they should be It is even necessary, therefore, to take the specific fore

, that these important constituents of coal gas will not

bear contact with the red-hot walls of the retorts; and One vile specimen, said to have come from the Continent, was examined by Mr. Draper, and found to consist of swept out of the retorts as quickly as possible, and that

the temperature of the retorts, especially of the upper nothing but uncrystallisable sugar. This firm has in parts, should be as low as possible; in fact, the destructheir case candles, coro-oleine, coro-stearine, specimens tion of these bodies is not by the temperature to which of wood shavings used in night-lights, in order to escape the coals are subjected, but by the heat of the upper parts the paper duty, 160 cuts to the inch board, lubricating of the retorts upon which the distilled gases and vapours oil from Rangoon, petroleum, palm nuts, palmitic impinge. acid, &c.

5. We have observed that, with one exception (marsh Mr. Hutchinson exhibits some fine specimens of car- gas), all these hydrocarbons are freely absorbed by chlorine, bonate and bicarbonate of sodium-so-called crystals of bromine, and strong sulphuric acid ; and that in each case bicarbonate of soda. Of course it is understood that a very similar set of compounds is formed, Dutch liquor they are pseudomorphous, retaining the rhombic form of being the homologue of the haloid compounds. This incarbonate of sodium; they are very beautiful and in- dicates the difficulty of determining the photometrical teresting objects ; also some very fine specimens of value of gas by the amount of condensation with chlorine caustic soda are exhibited.

or bromine ; for by such a process we have no knowledge of the particular hydrocarbon condensed. In my own

experiments I find that the condensation may be very difPROCEEDINGS OF SOCIETIES.

ferent, even when the gases examined have the same illuminating power ; and, conversely, we may have the

same amount of condensation for gases of very different ON THE PRESENT STATE OF THE CHEMISTRY illuminating powers: the number, therefore, 3*25, which OF GAS LIGHTING.

is sometimes taken as the co-efficient of power, is altoBy HENRY LETHEBY, Esq., M.B., &c.

gether unreliable.

6. We notice that all the richer and more condensible Delivered at Birmingham, before the Society of Gas Engineers.

hydrocarbons are condensable by cold, and, therefore, that

gas should not be subjected to a cold of 32°, or even much (Continued from page 10.)

below 509 Fahr. And now, in reviewing the facts which have been 7. It is a fact that water has little or no influence on any brought before us in an examination of the several hydro- of the hydrocarbons, except acetylene ; and as this exists carbons found in coal gas, the conclusions are

in gas only to a very small extent, there is little or no 1. That they belong to different groups, or series of danger from a copious washing of the gas before it goes to compounds, in which the proportion of carbon and the purifiers. hydrogen rise by successive increments of 2+ 2, and that 8. It is worthy of remark that the hydrocarbons are the amount of hydrogen in them progressively decreases. freely absorbed by oils, and by vulcanised india-rubber

In the Marsh gas series, for example, the proportion of tubing. This circumstance should be taken into account hydrogen is always two more than the carbon, thus :Marsh

in testing the illuminating power of gas, for I find that a gas, or Methyl-hydride, C2H4; Ethyl-hydride, flexible tube of about 30 feet in length will reduce the CH. ; Propyl-hydride, C,H, Butyl-hydride, č;H10; power of a weak gas to the extent of nearly 25 per cent. Amyl-hydride, C10H12, &c., all of which are found in the 9. It is not an unimportant fact that these hydrocarbons petroleums. In the next series, the Alcohol radicals, which may or fore, vitiate very different proportions of atmospheric air ;

consume very different proportions of oxygen, and, theremay not be present in coal gas, the praportion of hydrogen and, again, the explosive power of coal gas, when mixed is only one more than the carbon, thus:-Methyl, c.8; ; I with air, is much affected by the proportions of the richer

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