摘要:

INCLUDING THE PROCEEDINGS O FTHE “ SOCIETY OF PUBLIC ANALYSTS.”PUBLISHED MONTHLY.The Analyst and Mr. Wanklyn . . 137O n the Solution of difficultly-soluble Sub-stances, by A. H. Allen, k’.C.S. . . 139On Cocoa, by C. Heisch, F.C.S. , . . 142On the Production of Sulphuric Acid by theCombustion of C3al Gas, by CV. C.Young, E.C.S. . . . . . 143On a method of taking the Gravities of Fats,by G. W. Wigner, F.C.S. . , . . 145[No. 8.1 31st OCTOBER, 1876. r PRICE 6d. ~Z~ZFEZ~YP%~.ICorrespondence-Messrs. Hehner & Angel1 . 147Fuchsine in WiLe . . . , 148Capsaicin . . . . . . 148, 149Ava or Kava-Kava . . . . . 149The Aconite Alkaloids . . . . , 150Sulphur i n Coal, by JQ. Morgan, Ph. D. . 151Prosecutions under the “Sale of Food andDrugs Act’’ . . . . . , 153 IA. H. ALLEN, F.C.S.J. FALCONER EING.A. VYNTEK BLPTH, M.R.C.S.T. REDWOOD, PH. D., F.C.S.GI. W. WIGNER, F.C.S. il A. Dmid, PH. D., F.R.S., F.C.S.C. HETSCH, F.C.S.J. MUTER, PH. D., M.A., F.C.8.C. A. CAMERON, M.D.E. W. T. JONES, F.C.S.C. E. PIESSE, F.C.S

ISSN:0003-2654    

DOI:10.1039/AN87601FP009

出版商:RSC    

年代:1876

数据来源: RSC

摘要:

THE ANALYST.BALANCE.To carry 20 grammes in each pan ... 12 Guineas3, 200 9 , 9 , 14 ? ?17 500 7, 39 18 9 997 1000 ,, 7 9 25 9 9WOLTERS’ BALANCES.GRAMME WEIGHTS (in Mahogany Boxes).From 10 grammes to 1 milligramme 1+ Guineas7, 100 9 - 9 7 2 9 97, 200 77 7 7 % 9 9,7 500 77 97 3 ? TRE ANALYST.case is very different with the beam ; here the number of vibrations in a given time augment in theratio of the squares as the beam shortens, so that a beam one-third the length of another would performnine vibrations to one vibration of the longer, while the loss of sensitiveness on that score only amountsto one-third. We can, therefore, by using such short beams, afford to restore the requisite sensitivenessby lessening the distance between the points of gravity and suspension, and still retain to a great degreethe advantage of quick action.Another consideration of importance in this respect is the extreme light-ness of the beam as compared with the long one. The friction being much less, this would also causea greater freedom of action, and tend to accelerate the vibrations,The capabilities of this balance are such that it yields to the tenth part of a milligramme with thegreatest precision, and has a working range up to one thousand grammes.The appliance by which it is worked will be found extremely convenient. When not in use, all theknife edges are disengaged. By turning the handle, which is visible in the figui-e opposite, all the actingparts come into play one after the other. The whole range of motion of tmhe handle is about one-half ofa turn.Beginning the operation, the pans are freed first; they are easily brought to rest by gentlybringing their stoppers in contact with them by carefully turning the handle back again once, or twice ifnecessary. When they are perfectly quiescent, the further turning of the handle engages the suspensionpieces by gently and simultaneously bringing their knife edges in contact with their supports ; the end ofthe handle motion suspends the beam, and the balance is ready for use. After use the handle is turnedback again, by which everything is set out of action. This arrangement, besides the great convenienceit affords, prevents all unnecessary wear of the acting parts.I n order to enable the final operation to be performed in the perfectly closed case.a parallel actionand sliding rod serves to lift the rider and place it in the required position with the greatest ease. Therider can be used the whole length of the beam.To ensure greater strength the whole is fixed to a stout glass plate which is supplied with two spiritlevels. Thepieces, when apart, fit in a box, and can be carried about without any fear of injury in the transport.The knife edges and their supports are made of agate, and most carefully finished.The form I have adopted for the smaller weights from 0-5 downwards will also be found very con-venient. They are made of wire, turned up into a flat spiral, the inner end projecting and forming a littleupright by which it can easily be taken hold Gf. The number of coils indicates the number of >nits in eachdecimal, and the decimals themselves are distinguished by different thicknerszs of the wire.An inspection of this B:ilance is respectfully solicited a t my office, 55, Upper XaryleboneThe Balance is so arranged that it can easily be taken to pieces and put together again,Street, Portland Place, London, W.0.WOLTEBS,(Many years with L. OERTLINO,)Manu faciurer of Veights, C'hemical, Assay and Bullion BalancesTHE ANALYST.Now ready, crom Svo, 500 p.p., cloth, price 12s. 6d. (postage Sd).THE COMMERCIAL HANDBOOK OF GHEMICAL ANALYSIS,or Practical Instructions for the Determination of the Intrinsic or Commercial Value of SubstancesBy A. Normandy, Author of ‘I Practical Introduction to Rose’s Chemistry,’’ and Editor of Rose’sWith numerous‘( Will be found to be essential to the Analysts appointed under the new Act... . , . .In all cases the most‘4 I n a book of nearly 500 pages, we have simple yet scientifio instruction how to examine almost everyused in Manufactures, in Trades, and in the Arts.‘ 4 Treatise of Chemical Analysis.” New Edition.Enlarged, and to a great extent re-written, by Henry M. Noad, Ph. D., F.R.S.Illustrations,recent results are given, and the work is well edited and carefully written.” Natzcre.article of consumption. Metropolitan.CROSBY, LOCKWOQD & Co., 7, STATIONERS’ HALL COURT, LONDON, E.C.INTERESTING FACSIMILE REPRINTS,In crown tho., antique binding, or paper boards, 6s. ; antique morocco, 21s.; large paper copies, inHE COMPLEAT ANGLER ; Or, The Contemplative Man’s Recreation.roxburghe binding, 21s. ; antique morocco, $2 10s.By ISAACWALTON. This reprint of the first edition, published in 1653, is printed on paper similar to that ofThe quaint title page, the very clever drawings of fishes, and the antique head-pieces and the original.tail-pieces, are also faithfully copied by a photographic process, which exactly reproduces the origind.ELLIOT STOCE, 62, PATERNOSTER Row, LONDON, E.C.In crown avo., antique binding, or in paper boards, price 7s. 6d. ; morocco ant.:que, 21s. ; largepaper copies, price, in roxburghe binding, 21s.THE PILGRIM’S PROGRESS. A Reprint in Facsimile of the :First Edition of 1678The special characteristics of the first edition are carefully preserved-the colloquial language, quaintspelling, and curious side-notes, the peculiar forms and mixtures of types, the irregular use of capitals anditalics, are faithfully reproduced ; thus enabling the modern reaaer to realise the rude form in which JohnBuyan put his immortal allegory before the readers of his own day.ELLIOT STOCK, 62, PATERNOSTER Row, LONDON, E.C.Now ready, in small crown Svo., in antique binding or paper boards, 5s.; or in antique morocco, 21s.HE TEMPLE. Sacred Poems and Private Ejaculations. By Mr. GEORGE HERBERT,late Oratour of the Universitie of Cambridge. With an Introduction by the. Rev. Alexander B. Grot&,Editor of (‘ George Herbert‘s Works in Prose and Verse,”, and of the Aldine Edition of Herbert’s Poems.”6‘ Mr.Elliot Stock has done good service to all collectors of old and curious books by publishing in hisseries of facsimile reprints, the ‘ Sacred Poems and Private Ejaculations,’ which George Herbert, the saintlyparish priest of Bemerton, bequeathed as a legacy to the Christian world, under the title of ‘ The Temple.’It is only now, for the first time, that an attempt has been made to reproduce the original work exactly asit came from the hands of Messrs. Buck and Daniels, Printers to the University of Cambridge, in 1663,the year of its Author’s death. This editio p r i m p has been followed exactly, not only in its contentp,but in such minute details as the stopping of the volume, which is reproduced exactly the saxe in type,binding, and paper, the latter being of a curious and not disagreeable brown, which looks to an inexperiencedeye at least as if it had seen the reign of Charles 1.“-The Times.ELLIOT STOCK, 62, PATERNOSTER Row, LONDON, E.C.IN THE PRESS.ARADISE LOST, by JOHN MILTON.A Reproduction in Facsimile of the FirstELLIOT STOCK, 62, PATJBNOSTER Row, L O ~ O N , E.C.EditionTHE ANALYST.In Wrapper, 2s. 6d. On Roller and Varnished, 6s.\OOD CHART, ‘ving the Names, C!assification, Composition, Alimentary Value, Rates of Digestibility, E Adulterations, fests, kc., of the Alimentary Substances in General Use. By R. LOCRE JOHNSON,L.R.C.P., L.R.C.S., &c.LL One of the most useful publications of the time.”- Wieekly Review.London : HARDWICKE & BOGUE, 192, Piccadillp, W.€RICE 2s.CLOTH.HE MICROSCOPICAL STRUCTURE OF CERTAIN FRUITS AND ROOTS T to be met with in the Jams and Preserves of Commerce. By ARTHUR ANOELL, F.’R.M.S., PublicAnalyst, County of Hants.To be obtained of GILBERT, High Street, Southampton.LATTNER’S QUALI J!ATIVE AND QUANTITATIVE AIVALY SIS WITH THE BLOWPIPE. P Profusely illustrated, 515 pages, Svo., new, 1875. Published at 21s. Offered for a short time at 6s. 6d.LETHEBY on Noxious Trades, 1s. post free.Milk in health and disease, by A. HUTCHINSON SMEE.London : HENRY KIMPTON, Medical Publisher and Bookseller, 82, High Holborn.LETHEBY on the Right Use of Disinfbctants, 1s. post free.Circulating Library, 21s. per annum. List of Works on Chemistry, tc., gratis.Readr, pp.iv. and 73, price 2s. post free.HE ANALYSTS’ ANNUAL NOTE BOOK for 1875. Edited by SIDNEY W. T RICH. Contains the principal part of the Analytical matter of the year in a partially condensed form.To be obtained through the Post only of S. W. RICH, 23, Lloyd Square, London, W.C.-~In the Press and will shortly be published a revised and fuller Edition ofUTTER; ITS ANALYSIS AND ADULTERATION. By OTTO HEHNER B and ARTHUR ANGELL, Public Analysts.PROCEEDINGS OF THE SOCIETY OF PUBLIC ANALYSTS,”Vol. 1, 1876.(,‘ THE SOCIETY. OF PUBLIC ANALYSTS gives in the present volume a very satisfactoryaccount of its first year’s work.(( It has been instrumental in introducing some improvements in an Act which wouldotherwise have been even less satisfactory than it is now ; it has secured very usefuldiscussions on the general questions involved ; has produced through its members somevaluable analytical papers ; and above rill has led to united action among Public Analysts.(‘ The present volume gives not only the record of the actual work of the Society,Including abstracts of the discussions at the meetings, but also a reprint of the recentAct, all important public papers which have been issued in regard to i t ; reports ofprosecutions in any respect typical, and many letters, articles, and stray notes.TheCouncil has acted wisely in publishing the volume.”-La;met.6‘ This book should certainly be possessed by Public Analysts.”- Chemist and &uggigt.( 6 This is rather more than it purports t o bc, since it contains a number of paragraphsand leading articles.”(( Many valuable papers are reprinted, and the book is not only practically useful,but also is an indication of healthiness and earnestness on the part of one of theyoungest of our scientific societies.”--lrolz..THE ANALYST.Subscription--3s. 6d. per annum, post free.All literary matter to be addressed to G. W. WIGNEB, 79, Great Tower Street, London, E.C.Business communications, Adrertisements, &c., t o J. H. SCOTT, at the same address.Printed by ALFRED BOOT, 7, Mark Lane. E.C.. for the Proprietors; andPublishel by ELLIOT STOCK, 62, Pateiiioster llow, E.C

ISSN:0003-2654    

DOI:10.1039/AN87601BP011

出版商:RSC    

年代:1876

数据来源: RSC

摘要:

THE A N A L Y S T . “THE ANALYST,” AND MR. J. ALFRED WANKLYN. IT will probably be noticed by our readers, that the name of Mr. J. A. Wanklyn, which has hitherto appeared as a member of the Committee of Publication,” of this journal does not appear on the cover of the present number. It is with extreme reluctance that we feel compelled to explain the reason for the absence of Mr. Wanklyn’s name, but that gentleman has left us no alternative.I n our issue of the 31st August, we felt it our duty to comment on a certain case of prosecution for the sale of adulterated butter in Scotland. One of the chemists engaged in the case chose t o feel affronted by our strictures, and instead of writing to us direct, addressed a letter to a Glasgow paper, in which he attacked The Analyst, in no measured terms.A copy of the paper containing this letter was sent to us, and on September 30th we made a short reply to the writer, (Mr. Dittmar.) Meantime, on September 12th, a meeting of ‘‘ The Society of Public Analysts,” was held at Glasgow, when the matter was mentioned, and Mr. J. A. Wanklyn, suggested the passing of a vote of censure on himself, and his colleagues on the ‘‘ Committee of Publication.” The absurdity of this proposition was apparent to everybody, except Mr.Wanklyn, and consequently, it found no seconder. The incident, so far as Mr. Dittmar was concerned, terminated by a decision being arrived at, to leave the matter in Mr. Wanklyn’s hands, on the understanding that he (as he happened t o be Chairman at the meeting), would see that some notice was inserted in The Analyst, with a view of soothing the feelings of the chemist, who fancied himself aggrieved.A meeting of the (( Committee of Publication” was held shortly afterwards, and Mr. W anklyn was summoned in ordinary course ; he, neverthelem, omitted to attend, and has not in any way communicated with The A.lzalyst on the subject he was deputed to attend to.He has considered it consistent with his position as a member of a Committee, openly to attack his colleagues in the columns of a contemporary paper. To show that we do Mr. Wanklyn no injustice, we reprint a letter bearing his signature, which appeared in the Chemical News, of the 6th inst. We also print a letter addressed by the Editor of this paper t o the Chemical News, to which letter, however, the Chemical News, has thought fit to refuse insertion.In that journal of the 13th inst., Dr. Muter vindicated his own position against Mr. Wanklyn’s charge, and in the same paper, on October 20th, Dr. Dupr6, and Mr. Heisch (in a letter bearing date, October 9th), indignantly repudiated Mr. Manklyn’s imputation, that though members of the Publication Committee,” two other gentlemen were ‘‘ alone responsible for the contents of the paper.” We think that this short explanation, taken in connection with the letters we print below, will be considered a sufficient justification for the omission from the list of the “Committee of Publication,” of the name of Mr.J. Alfred Wanklyn. Mr. Wanklyn, however, has not been idle.138 THE ANALYST.COPY.] To THE EDITOR OF THE (( CHEMICAL NEWS.” Sm,-The subject of the recent attack on Professor Dittmar was brought before the notice of the Glasgow Meetin of the Public Analysts, and the attack was condemned by those present at the meeting. So decided was t f e expression of condemnation that a vote of‘ censure on the Committee of Publication was even mentioned ; but in place of so extreme a course (which, in my opinion, ought ko have been followed) an ilzdirect vote of censure was carried, the resolution being to the effect that befwe commentaries on adulteration-cases are inserted in The Analyst the chemists implicated should be communicated with.I observe that the current number of The Analyst pnrports to give an account of the Glasgow Meeting of the Society, but does not in any way record the resolution passed a t that meeting.I observe also an editorial commentary on Mr. Dittmar which is in direct oppoiition to the resolution passed by the meeting ; and I take this opportunity of making known that the Society of Public Analysts have no real costrol over The Analyst, which is the property of Mr. Wigner and Dr.Muter, who alone are responsible for the contents of the paper. October 2, 1876. I am, &c., J. ALFRED WANKLYN. COPY.] To THE EDITOR OF THE “CHEMICAL NEWS.” Sm,-Had Mr. Wanklyn paused to make a few enquiries before writing to you, he would not, I am wre, have dragged my name into this discussion, because he would have found that at the time The Analyst published the article and report which originally gave him offence, I was enjoying a ramble in Switzerland, and I can safely say never wasting a thought either on butter or Mr.Dittmar. I n fact Mr. Wanklyn and myself have precisely the same amount of responsibility for the contents of The Analyst for September, viz., that we were both members of the Committee of Pzcblication, and that we each of zcs neglected our obligations as sucli, nnd stayed away from the meeting, and therefore we ought to be the last to throw stones at those who did their duty by attending. My position as one of the ‘ I registered proprietors ” of the paper was simply taken to get the Society out of the difficulty that, not being corporate, they could not legally hold a copyright, and I will have much pleasure in handing over the position (involving, as it does, pecuniary responsibility) to any other member who may be public spirited enough to accept it.I trust Mr. Wanklyn will withdraw his remarks so far as I am personally concerned. I am, &c., October 7th) 1876. JOHN MUTER. COPY .] SIR.-I have to ask for space in your columns to reply to a letter which appears over the signature of Mr.J. Alfred Wanklyn, in your issue of the 6th instant. Mr. Wanklyn is pleased to speak of the ‘‘ recent attack ” made on Mr. Dittmar in The Analyst, which ‘‘ attack,” he says, was condemned by a recent meeting at Glasgow ; further, that a vote of censure on the “ Committee of Publication ” was suggested, and, in Mr. Wanklyn’s opinion, ought to have been passed. The suggestion in question was made by Mr.Wanklyn, himself a member of the Committee he mished to censure, but it met with no support and fell to the ground. Mr. Wanklyn complains that a certain resolution, which he states was passed, is not given in The Analyst report. It need,hardly be pointed out, that an ordinary report of a meeting does not, necessarily, include a copy of the actual minutes.For such information 1 beg to refer Mr. Wanklyn to the minute book of 6‘ The Society of Public Analysts.” To Mr. Wanklgn’s assertion that a note in the last number of The Analyst, i L is in direct opposition to the resolution passed at the meeting,” I have to give an unqualified and emphatic denial. Anybody capable of understanding plain English who rends the resolution, as quoted by Mr.Wanklyn, side by side with the article in The Analyst, commenting on Dr. Dittmar’s published explanation, will, at once, see that the only “ direct opposition” is that evidenced by the animus of Mr. Wanklyn’s letter. The concluding paragraph contains a statement which is so untrue and so clearly intented to be offensive, that it is my duty to contradict it absolutely.Mr. Wanklyn says :-“ The Society of Public Analysts has no real control over the Analyst,” but that two individuals, whose names he gives, ‘‘ alone are responsible for the contents of the paper.” This assertion is clear enough. The answer shall be none the less unmistakeable. A ‘( Committee of Publication,” consisting of six members of the council of ‘‘ The Society of Yublic Analysts,” has, from the first, been responsible for the contents of The Analyst, meetings of such committee have been held periodically, and I am in the position to a5rm that in no case has any matter appeared in The Analyst which has not been previously submitted to, and approved by, the Committee.If, when the article to which Mr. Wanklyn objects, was agreed to, Mr. Wanklyn was not there, it was, presumably, his own fault.If he attended and voted against its insertion, and was in a minority, he should-as minorities always have to do-submit gracefully to the majority. I n any case, it would be well if, in future, Mr. Wanklyn would satisfy himself of the accuracy of his statements, before he allows them to appear in print. To THE EDITOR OF THE ‘‘ CHEMICAL NEWS.” Yours, Bc., October 9, 1876.THE EDITOR OF (‘THE ANALYST.”THE ANALYST. 139 COPY .] TO THE EDITOR O F THE “CHEMICAL NEWS.” SIR,-Referring to a letter which appears in your last number, signed by Mr. Wanklyn, we ask your permission to make a short statement, as follows :- We beg to say that we are members of the ‘‘ Committee of Publication ” of The Analyst ; that we consider we have devoted a fair amount of attention to our duties, that we have no wish to shirk our responsibility for anything that has appeared in The Analyst ; and consequently, we are in a position to deny, as we hereby emphatically do, Mr. Wanklyn’s assertion, that two other members of the ‘‘ Committee of Publication” alone are responsible for the contents of the paper. Whatever may be Mr. Wanklyn’s view of the duty of any one holding office, we, for ourselreg, can say that unless me felt oiirselvei both able and willing to perform our share of the duties of the Publication Committee of The Analyst, we would certainly not allow our names to be published as members of that Committee. LONDON, Oct. 9th, 1876. Yours, &c., CHAS. HEISCE, A. DUPRE;.

ISSN:0003-2654    

DOI:10.1039/AN8760100137

出版商:RSC    

年代:1876

数据来源: RSC

摘要:

THE ANALYST. 139 ON THE SOLUTION O F DIFFICULTLY-SOLUBLE SUBSTANCES. “By ALFRED H. ALLEN, F.C.S. SOME years ago, in a letter to the Chemical News, (Vol. XXII., p. 57), I described a mode of effecting the solution of difficultly-soluble iron ores and slags, by heating them with strong hydrochloric acid in sealed tubes, and experience having shown the method to be extremely valuable in certain cases, I have thought it worth while to bring my results before the Society in the form of a paper.I n the analysis of minerals and metallurgical products containing iron, it is often necessary to determine whether that metal exists as a ferrous or a ferric compound. Of course, this is easy, provided the substance is readily decomposed by acids, but in the case of insoluble or dacultly-soluble minerals and slags, the problem is by no means easy of solution. Protracted boiling with acid is often very inconvenient, and sometimes useless ; while any process of fusion almost necessarily involves more or less oxiddtion of ferrous compounds.Mr. C. E. Avery (Chemical News, Vol. XIX., p. 270), has proposed t o decompose silicates with a mixture of a fluoride and a mineral acid, and the same method in a somewhat modified form hns been described by Messrs.Wilbur & Whittlesey (Chemical News, Vol. XXII., p. 2). These processes have a certain value of their own, but the use of fluorine compounds is not always convenient, though of course in some cases indispensable. It might be anticipated that acids acting under pressure in sealed tubes would effect the decomposition of many refractory minerals, which resist ordinary methods of treat- ment, and this view is fully borne out by experience.This mode of treatment has the great advantage that it can be continued for any desired length of time, or discontinued and recommenced at will, and that the subsequent steps of the analysis can be performed after any interval of time most convenient t o the operator.The method of pocedure I have been in the habit of adopting is simply as follows : A gramme of the finely powdered mineral or slag is placed in a piece of combustion tube carefully sealed a t one end. From 20 to 30 C.B. of pure fuming hydrochloric acid are poured in, and the other end of the tube drawn out and carefully sealed in the blowpipe flame.The tube when sealed, should be about eight or ten inches in length. The proportion of acid used is such as to ensure a large excess; this prevents undue weakening by saturation of the acid, and has other obvious advantages. *Read at a, Meeting of “The Society of Public Analysts,” at Glasgow, Sept. 12, 1876.140 THE ANALYST. The tube is now ready for heating. I n many cases, the mere heat of a water-bath is amply sufficient to ensure perfect decomposition.As fuming acid is employed, there is always considerably more than one atmosphere of pressure even at 100n C., but decomposition is in many cases greatly facilitated by use of a higher temperature. A very convenient bath for the purpose is formed by B saturated solution of nitrate of sodium, which boils at 1209 0.I n some cases, it is desirable t o obtain a still higher temperature, in which case chloride of calcium can be conveniently employed. I n all cases, however, I prefer t o subject the tube to a temperature not exceeding 100° C. first of all. This enables the sealing to be tested, and perhaps causes some reduction of the internal pressure, owing to partial neutralization of the acid.I n many cases the temperature of looQ C., is amply sufficient to effect perfect decomposition of the sample. This is true of blast-furnace slag, all the varieties of which are readily decomposed at looo C. The slag now obtained in England from the manufacture of spiegeleisen, contains from 30 t o 40 per cent. of oxide of manganese, and is decomposed with such facility that if it be added in a powdered state to hot hydrochloric acid, the mixture will be converted, almost instantly, into a transparent jelly.‘( Tap-cinder ” and Bessemer-converter slag are far more refractory, and require somewhat prolonged treatment at an elevated temperature. Basalt is readily and completely decomposed when heated with fuming hydrochloric acid in a sealed tube.Titanic iron sand, if finely powdered, suffers perfect decomposition under the same treatment. ‘‘ Ore-furnace slag ” from copper-smelting, is decomposed with difficulty. Finely powdered burnt red brick, gives up some iron to the acid, but is very Chrome-iron ore suffers ver7 little change. Tin-stone is partially dissolved, but I have not succeeded in effecting perfect A blank experiment showed that the acid had no sensible eEect on the glass of the tube, even when heated in it t o about 169O C.for five hours. In all cases it is exceedingly easy t o watch the progress of the decomposition. When complete, the tube can be left alone till it is convenient to proceed with the analysis. For the determination of the ferrous oxide, it is only necessary to open the tube, wash the contents into a basin, and titrate at once with standard bichromate.I n fact, blast-furnace slag rarely requires a sealed tube at all. imperfectly decomposed. solution. The silica rarely separates in a gelatinous state. It has been proposed to employ a mixture of three parts by weight of concentrated sulphuric acid, and one of water, for a similar purpose. Experiment shows that this is by no means a satisfactory modification, at least for the treatment of ferruginous silicates and similar materials, the sulphate of iron separated preventing further action on the undecomposed portions of the substance.‘In fact, I have succeeded in effecting complete decomposition by sulphuric acid in comparatively few cases. I t is evident that treatment; in sealed tubes is not at all an advantageous plan of employing sulphuric acid, €or unless the temperature be dangerously high, the vapour ofTHE ANALYST.141 the acid exerts no great tension, and thus all the advantages of working under high pressure are lost, and one might as well use an ordinary bottle or corked tube at once. But at very high temperatures sulphuric acid is able t o effect decompositions with great facility, and, at a red heat, it is one of the most convenient and powerful re-agents we possess.Of course “ red-hot sulphuric acid ” is employed in the form of acid sulphate of potassium. The sodium salt is often recommended, but it will not adyantageously replace the potassium compound, as it decomposes at an inconveniently low temperature, and gives off much more sulphuric anhydride.The acid sulphate should always be fused in the platinum crucible first of all, to drive off water and free acid, the sample being subsequently added. It is desirable to test the purity of any fresh sample of ( ( bisulphate ’’ before using it. A quantity of the salt sold me by one of our principal operating chemists contained a considerable quantity of silver, an impurity doubtless dissolved from the vessel in which the salt had been fused by the manufacturer.By fusion with acid sulphate of potassium, nearly all the above-mentioned refractory substances can be readily decomposed. Brick-dust leaves nothing but pure white silica, and the same is true of all clays. Instead of treating ordinary soluble iron ores with hydrochloric acid, and having the unsatisfactory item of “ silicious matter ” to examine further, it is far better to fuse the ore with acid sulphate at once, by which means pure white insoluble silica is obtained, and all the other constituents pass into solution on treating the product of the fusion with acidulated water. I n presence of pyrites or ferrous compounds it is best to add a crystal of nitre when the sample is placed in the crwible.The silica obtained is sometimes ochreous if too high a temperature has been employed, but it is readily purified by treatment with hydrochloric acid after pouring off the liquid. No evapor- ation to dryness t o render the silica insoluble is requisite. It is a pity that a re-agent so valuable and so widely applicable as the acid sulphate of potassium is not more commonly employed.I have made a few egperiments in another direction, and although the results possess merely a negative value, this appears a convenient occasion t o place them on record. It is well known that a hot solution of phosphoric acid readily aots on glass, and it occurred t o me that the decomposing power would probably be greatly enhance4 i f fused meta-phosphoric acid were employed instead of a mere solution.This deduction was fully borne out by experiment. A fragment of window-glass about an inch square was treated at a low red heat in a platinum crucible with glacial phosphoric acid. I n an hour or so it was decomposed nearly to the centre, and the change was accompanied by some very remarkable and characteristic appearances. With powdered glass the reaction was still m r e perfect, and there is no doubt that fusion with phosphoric acid might be employed as a means of decomposing silicates. The difficulty consists in the subsequent treatment of the resulting meta-phosphates. I n practice, this presents such difficulties, that I have been compelled to abandon the idea of making the method useful, though it is possible that there are exceptional cases in which it might be made of service. The platinum crucible used for the fusion is seriously attacked.

ISSN:0003-2654    

DOI:10.1039/AN8760100139

出版商:RSC    

年代:1876

数据来源: RSC

摘要:

142 I THE ANALYST. I 1 ON THE COMPOSITION OF DIFFEltENT KINDS OF COCOA. CARACAS ...I *TRINIDAD.. . SURINAM ... GUAYAQUIL. GRENADA ... BAHIA ...... CURA ........ PARA ........ By CHARLES HEISCH, E.C.S. 2.15 *9 *80 1.75 *60 *90 *95 1.40 IT is well known, that different varieties of cocoa fetch very different prices; but as far as I am aware, no careful examination has been made to ascertain if these differences are caused by any difference in their composition regarded as articles of food, or if they be due solely to differences in flavour, which after all may be only matters of taste.In none of the published analysis of cocoa which I have seen, is any mention made of the kind of bean nnalysed, it is therefore not surprising that the results published vary very considerably. Thus, while in Dr.Hassall’s book we are told that cocoa contains albuminoid matter 16.7 per cent. ; in Dr. Parkcs’, Practical Hygiene, it is stated to contain from 13 to 18 per cent. of protein substance. I n neither case is it mentioned, vhether the bean was examined raw, or after roasting. Having through the kindness of a friend obtained samples of rarious cocoa beans, both raw and roasted, which he assured me were unmixed, I made a number of analyses of the roasted beans, which as far as food is concerned, are by far the most interesting, as I believe the raw bean is never employed.They are not so complete as I had hoped to make them, but they comprise the more important constituents, and as such analyses can be done only in the intervals of more pressing work, I prefer leaving the remaining less important constituents for a future communication. In the first column of the Table, is noted the proportion of husk in the different varieties.This difference appears to be mainly due to the husk in some kinds being much thicker than in others; in all cases these thick husks separate much more from the bean in the process of roasting, and can be taken off with much greater facility.The other estimations are made on the roasted bean after r e m o d of the husk. The albuminoids are calculated from the total nitrogen found by combustion with soda lime, the nitrogen contained in the theobromine is thus included, but in the roasted bean this is so small that the difference is hardly worth consideration; hereafter, I hope to estimate the theobromine in the different varieties, as well as the Btarch, gum, cellulose, &c.It will be observed, that in none of the above samples do the albuminoid substances reach the amount mentioned by Hassall or Parkes, but as neither of them give the method by which the albuminoids were ascertained, no attempt can be made to account for the difference.The amount of these substances in Para, which is about the lowest priced variety, is, with one exception, the highest in the table, so that, viewed as an article of food it is superior to s3me of the more expensive kinds. The soluble ash consists t o a great extent of phosphate of potash, the phosphoric acid in the portion insoluble in water being mostly if not entirely combined with magnesia.The results are shown in the following table. 1.80 1.90 1.55 1.75 1.80 1.70 1.95 1.65 ~~ ~ 1 RESULT OF EXAMINATION OF ROASTED BEAN AFTER BEMOVAL OF E U S y / I 4-32 3-84 3.76 4.14 3.90 4.40 3.72 3.96 1 1 Per Cent. 32.19 32.82 28.35 30.47 35.70 35.30 39-41 26‘33 age of Husk. 13.8 15-5 15.5 11.5 14.6 9.6 12.0 8.5 Fat. Nitrogen. Albuminoid Substances. 48.4 49.4 54.4 49.8 45.6 50.3 45.3 , 51.0 1.76 1.76 1-76 2.06 1.96 1-17 1.37 2.00 11.14 11.14 11.14 13-03 1‘2.40 7.40 8-67 12-66 3.95 2.80 2.35 3-50 2.40 2.60 , 2.90 1 3.05 L I I 1 I I Phosphoric Acid in culated a3 1 ‘54 ‘93 1‘23 1 -87 1 -35 1 *26 1.13 1.00 --l---! Starch, I I * I am inclined t o think that the Trinidad sample was not of the finest quality.

ISSN:0003-2654    

DOI:10.1039/AN8760100142

出版商:RSC    

年代:1876

数据来源: RSC

摘要:

THE ANALYST. 143 ON THE PRODUCTION OF SULPHURIC ACID BY THE COMBUSTION OF COAL GAS, &c., By w. c. YOUNG, F.C.8. IT is the belief of many eminent gas engineers, that the sulphur compounds in coal gas are converted into sulphurous acid by combustion in burners used for lighting purposes, and they are confirmed in their belief by the published opinions of several eminent chemists. The experiments, which are the subject of this paper, were made with the purpose of determining the amount of sulphurous and sulphuric acid respectively, that is produced by burning coal gas in different burners, and were commenced nearly two years ago, their progress having been interrupted until lately.The apparatus in use at the Official Testing Offices for the estimation of sulphur in gas, is that known as the Gas Referees’ apparatus, (see Fig.,) and is of the following description.The gas is burnt in a small Bunsen burner with steatite top, which is mounted on a short cylindrical stand, perforated with holes for the admission of air, and having on its upper surface a deep circular channel, to receive the wide end of a glass trumpet-tube, on the top of the stand; between the narrow stem of the burner, and the surrounding glass trumpet- tube, are placed pieces of commercial sesqui- carbonate of ammonia, weighing in all about two ounces.The products, both of the combustion of the gas, and of the gradual volatilization of the ammonia salt, go upwards through the trumpet-tube into a vertical glass cylinder packed with glass balls to break up the current, and promote condensation.From the top of the cylinder there proceeds a long glass tube to increase the draught and form an exit for the uncondensable gases. I n the bottom of the cylinder is fixed a small glass tube, through which the liquid formed drops into a beaker placed beneath. The condensed liquor contains the sulphur as sulphate of ammonia. It is supposed by some that the complete oxidation of the sulphur is effected by nitric acid, formed by the oxidation of the ammonia vapours passing over the flame.The following experiments prove that this is not so, and that the Bunsen flame is sufficient alone to complete the oxidation. The gas was burnt in a gas referees’ apparatus having no carbonate of ammonia round the burner. On the top of the glass balls a few crystals of pure carbonate of soda were placed, so that the interior of the cylinder was kept alkaline, and the absorption of144 THE ANALYST.the acid vapours assured, Result :- Care was taken that no ammoniacal vapour was present. Apparatus with Apparatus with (N H 4)2 CO 3 round burner. Grains S in 100 c. ft. Na 2 Co 3 on top of cylinder. Grains S in 100 c.ft. 1. ... ... ... 9.27 ... ... ... 9.65 2. ... ... ... 10.30 ... ... ... 10.60 3. ... ... ... 9.40 ... ... ... 9.75 4. ... ... ... 11.20 ... ... ... 11.60 Having found that the modified apparatus gave as perfect results as the original, the Bunsen was replaced by a common fish-tail and other burners successively, and the gas burnt at the rate of about 1.25 c. ft.per hour (that being as much as the draft through the apparatus would permit). The condensed liquor was then made up to a known bulk, a portion boiled with hydrochloric acid, so as to expel any sulphurous acid that might be present, and the S estimated as Ba SO,. Another portion was acidified with nitric acid and set aside for 24 hours, and the S estimated as before; the difference between the two estimations being ascribed to sulphurous acid.The results are stated in grains of sulphur per 100 c. ft, of gas. FISH TAIL BURNER. 1. ... 11.1 ... a 2 ... 10.9 2. ... 12.1 ... -3 ... 11.7 3. ... 9.3 ... *O ... 9.1 LONDON ARGAND BURNER. 1. ... 12.7 ... -4 ... 12.6 2. .L I 11.3 ... Q2 ... 11.1 3. ... 11.4 ... *4 ... 11.3 COMMON IRON ARGAND. 1. 1.. 8.5 ... -0 ... 8.5 2.... 9.1 .., -2 ... 9.0 3. ... 10.3 ... *4 ... 10.1 As Ez SO4. AS S02. S by Referees’ app. In these experiments the conditions were favorable to the production of sulphurous acid, as the supply of air to the burner was little more than sufiicient to produce a steady flame, and of course would be less than when in ordinary use. As will be seen, however, the oxidation was as complete as in the Bunsen burner, and but a mere trace of sulphurous acid was obtained in either case.There can be no doubt, that the notion that sulphurous acid was the principal product of the combustion of sulphur compounds in coal gas, arose from the statements to be found in most text-books, that when sulphur or sulphuretted hydrogen is burnt with an excess of oxygen, the product is sulphurous acid.When sulphur is burnt in dry oxygen, sulphurous acid alone is produced of conrse, but in moist oxygen, sulphuric acid will be found in addition, The statement is insufBcient as regards sulphuretted hydrogen, as sulphuric acid may always be found in the product of its combustion. I n order t o see how far the simultaneous production of water during the combustion of sulphur compounds affected the oxidation of the sulphur present, I burnt sulphuretted hydrogen, a mixture of hydrogen and sulphuretted hydrogen, and coal gas charged with bisulphide of carbon, respectively, under a trumpet-tube fixed to a vertical cylinder, 2 feet high and 4 inches in diameter-about twice as large as the condenser in the Befereed sulphnr apparatus-differing in shape from the latter, in having two necks atTEE ANALYST.145 the top. I n one of these necks was fitted a separating funnel, through which a strong solution of pure caustic soda was slowly run on to the glass balls, with which the interior of the cylinder was filled; to the other was fixed an eduction tube. I n the bottom of the cylinder was fitted a tube through which the liquid ran into a veshel beneath.I n this way a large alkaline surface was obtained, which was being constantly renewed from the stoppered funnel. One portion of the liquor obtained was boiled with H C1, another diluted very considerably with water, acidified with HNO,, and set aside for 24 hours ; the S estimated in both as Ba SO,. The H,S was burnt at as low a rate as possible, and the result showed that very nearly 1 per cent.of the 8 was converted into H,SO,. A mixture of E acd H2S containing 4 per cent. of the latter, produced no sulphurous acid during its combustion. The coal gas was charged with bisulphide of carbon, by passing it over a solution of the latter in olive oil. In the first experiment, the gas was burnt at the rate of -5 c. ft. per hour, the result showing a total of sulphur amounting to 444 grs. per 100 c. ft., of which 422 grs. (95 per cent.) had been converted into H, SO,. In a second experiment the solution of bisulphide used was very much stronger, and the gas was burnt at the rate of -2 c. ft. per hour. The result was as follows:- Total sulphur, 1644 grs. per 100 c. ft., of which 1260 (or 76.7 per cent.) was converted into H, SO4. It is evident from these experiments that the presence of aqueous vapour, or, its simultaneous production, does very materially effect the oxidation of sulphur, and that, practically, the sole product of the oxidation of the sulphur in coal gas, is sulphurio acid, even if that impurity be present in very large quantities.

ISSN:0003-2654    

DOI:10.1039/AN8760100143

出版商:RSC    

年代:1876

数据来源: RSC

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TEE ANALYST. 145 ON A SIMPLE METHOD OF TAKING THE GRAVITIES OF FAT AT HIGH: TEMPERATURES.* By G. W. WIGNEE, F.C.S. SOME two months since, I published in The Analyst, a short note, on the use of the well known specific gravity bubbles, for the purpose of taking the specific gravities of melted fats a t high temperatures. The method seemed to offer several advantages, amongst others it is easy to work on a very small quantity of the pure fat, and a readihng of temperature which can be made with considerable accuracy, is substituted for a weighing at a high temperature, which is, to say the least, a difficult and delicate operation.The process itself contains one element of error. The bubble, consists of a hollow glass bead, with a tail or shank. The definite adjustment of the bubble to the required specific gravity is made by grinding this shank, and testing this bubble in a solution which is:of the required specific gravity, at a temperature of 60Q F.When, however, the bubbles are used in hot fats, the expansion of the air sensibly alters the shape and dimensions of the bubble. The consequence is, that the gravity of the bubble deter- mined at 60°, does not represent the actual gravity of the fat at the temperature at which the experiment is made, but requires a certain correction.~~~ * Read at a meeting of the Society of Public Analysts, at Burlington House, on June 14th, 1876.146 THE ANALYST. The results, however, are perfectly regular and concordant, and this slight correction is therefore easily applied ; while the figures obtained are so reliable that many samples of butter need no further examination. I am convinced, that when it is desired to take the gravities of liquid fats at temperatures higher than 1000, the bubbles will be found to give much more accurate results than can be obtained by weighing.The mode of manipulation which I adopt is as follows :- The fats t o be tested, are melted and kept for some time (say half-an-hour) at a temperature considerably in excess of their melting point (say 180") so as to ensure perfect fusion and uniform mixture. A portion of each is poured into a test tube, of about 5-in.by 3-in. size, which is filled within an inch of the top. These test tubes are fitted with corks having a notch in the side to allow for the expansion and contraction.The corks are bored with holes, through which are inserted small pieces of glass rod with rounded ends, long enough to dip &-in. or more below the surface of the fat. After the bubbles are put into the fat in the tubes, these corks holding the glass rods are inserted, and the bubble is thus forced entirely below the surface of the fat, and therefore is free from the slight surface adhesion which would otherwise exist.The test tubes are then dropped into holes in a sheet of copper which supports them by their flanges, and are immersed in a beaker of water, at a temperature of say 100" F. This beaker is in turn supported by a tin or copper ring in another larger beaker containing water, at the same temperature, and the whole arrangement is then put on a small sand bath. The burner is so arranged as to raise the heat very slowly, lo F.per minute is the greatest rate of increase which must be used under any circumstances. As the temperature rises, the bubbles will be seen to detach themselves from the ends of the glass rods. They will fall at first very slowly, but still there mill be no difficulty in observing the time at which the first line of separation appears, within twenty seconds.Following this procedure, I have worked with bubbles of various specific gravities, but the following results show those which I consider the most generally suitable. I took a sample of ordinary butter, and separated the pure fat in the usual way. I weighed the melted fat according to Muter's method at looo, and 135" Faht.The results, all calculated from actual weighings in a glass bottle, (no allowance being made for the expansion of the bottle) were as follows : -. j 907*2 Specific Gravity a t 100" F ... ... Compared with water a t 60" F ... ... ... Compared with water at 100" F ... ... ... Specific Gravity at 135" F ... ... Compared with water a t 60" F ... ....., Corresponding to "Actual Density," a t 135" F Compared with water at 135" F ... ... ... Corresponding to"' Actual Density," a t 100" F ... } 912.1 ' * ' \ 895.2 1 906.7 ... A bubble, the specific gravity of which (as determined by a mixture of spirit and viater) was 896*, was tested in this Fat and sank at 1 3 5 O . The indication given is therefore 896', as against a real specific gravity of 895.2 at 1 3 5 O F, which corresponds to an error of 24 F in temperature of the specific gravity bottle at the time of taking the weight. I took some of the same butter fat and mixed it with lard fat in different proportions. The fats were measured when in a melted state instead of being weighed, and were successiyely increased by one sixth.No. 2 five-sixths lard, one-sixth butter, and No.7, pure butter. So that No. I is pure lard.THE ANALYST. 14'7 These mixed fats were each tested with five bubbles of the following gravities at 60Q F. A and 3 ... ... ... ... 889.0 C and D ... ... ... 888.0 E ... ... ... ... 896.0 The following table shows the actual densities " of these fats at looQ F, and the temperatures at which the bubbles were found by actual experiment to sink.?umber. 'ercentagc of Butter. 0 16 33 50 66 83 100 Actual Density. 905.3 906.2 907.1 908.6 910.8 911.2 912.1 Temperature at which the bubbles sank. Degrees Faht. A B 127 131 136 139 141 145 146 126 131 136 139 141 145 147 C 129 132 137 141 142 146 149 D 129 132 137 140 143 145 148 E 114 117 122 124 128 132 135 - From these results it follows, that in a sample of so called butter having an actual density of 91lV (the density, which has been fixed by Muter as that above which, samples may be safely passed), beads mill sink as follows :- Sp. gr. of Beads ... ... ... 889*(! 896.0 Temperature ... ... ... 145" F 132" F. If the bead sinks at any temperature lower than these, the butter will need further examination by actual determination of the percentage of fatty acids. But as a guide t o the gravity it may be assumed that a difference of one degree in the sinking temper- ature indicates 030 actual density, equal to about -35 per cent. of fatty acids, and nearly 3 per cent. of foreign fats.

ISSN:0003-2654    

DOI:10.1039/AN8760100145

出版商:RSC    

年代:1876

数据来源: RSC

摘要:

THE ANALYST. 14’7 CORRESPONDENCE. BUTTER ANALYSIS. To THE EDITOR OF THE “ANALYST.” SIR,-In answer to Dr. Muter’s letter on the above subject, in the September number of Z‘h Analyst, will you please give insertion t o the following remarks :- I n June, 1874, we published our book on Butter Analysis, in which we showed, that the detection of foreign fats in butter by chemical means was a ccmparatively easy matter, and for about two years, Dr.Muter allowed us to get the credit of having first arrived at the complete solution of the much discussed Gutter question. The passages, he wishes to point out are the following : The really exact mode of detecting tallow in butter, can only be based on a proper separation and estimation of the various fatty acids. This is an operation which necessitates practice, and is also tedious.” Anyone with a moderate acquaintancc with the subject might have said as much.On page 587, we get however, something more definite, Dr. Muter, says: “ want of space forbids any description of the mode adopted in separating and estimating the fatty acids, but we shall soon be able to recur t o the subject, when a process will be detailed, which is found most workable, and which is a modification of Heintz’s method.” Dr. Muter, never recurred to the subject, and it is left to the reader to decide, whetbcr the method had actually been worked out by Dr. Muter, or whether he only hoped to get at one, by following Heintz’s method. Be that as it may, he neTier said one word about it until April or May, 1876. Dr. Muter, now refers to pages 586-7 of the Food Journal, for 1870. Yours, Stc., OTTO HEHNER. ARTEUR AXGELL.

ISSN:0003-2654    

DOI:10.1039/AN8760100147

出版商:RSC    

年代:1876

数据来源: RSC

摘要:

148 THE ANALYST. CAPS AICIN, THE ACTIVE PRINCIPLE OF CAPSICUM FRUITS. [Pharmaceut. Journal, No. 315, 1876, p . 21.) Mr. C. F. THRESH appears to have succeeded in isolating the pungent principle of cayenne. The first step is to obtain the oily fluid named by Buohheim (‘ capsicol,” by treating the powdered fruit with ether, distilling off the ether, dissolving the residual extract in boiling caustic alcoholic ley, diluting with water and precipitating with barium chloride ; this precipitate is washed, dried, and treated with ether, and upon evaporation the oily capsicol is obtained, which may be purified by a repetition of the process.From capsicol; capsaicin may be obtained in two ways- (a) Capsicol is dissolved in twice its volume of almond oil, and agitated with three successive portions of proof spirit, the alcoholic solution is separated, and upon evaporation leaves a red-brown fatty residue, which when dissolred in dilute solution of potash, and treated with dilute ammonia, deposits, on standing pearly white crystals of Capsaicin.THE ANALYST.149 (6) The capsicol is dissolved in dilute potash, precipitated by ammonium chloride, the coloured precipitate re-dissolved in potash, and re-precipitated at 120° F by ammonium chloride in excess-in a few day8 an abundant crop of capsaicin crystals will be the result.Capsaicin may also be obtained by dialysing the tincture of capsicum-the dialysed solution has an acid reaction. Capsaicin is powerfully pungent, the most minute portion, if volatilised, causing severe fits of coughing. It dissolves slightly in cold water, more readily in boiling water, a portion at that temperature becoming volatilised, and causing long continued fits of sneezing, the excess of what is taken up by the water melts and floats on the surface of the fluid 8s a colourless oil.The hot solution precipitated by the addition of a strong acid deposits crystals. Capsaicin dissolves readily in proof spirit, giving, when not too dilute, white precipitates with barium and calcium chlorides, both soluble in ether. Silver nitrate gives a precipitate which dissolves in dilute ammonia, and the solution when boiled darkens in colour and deposits a curdy brown-black precipitate. Capsaicin is volatilised slowly at 212a F. and may be obtained as a sublimate of fatty globules, if mixed with water and distilled. The distillate has a distinctly pungent taste. A. W. B.

ISSN:0003-2654    

DOI:10.1039/AN876010148b

出版商:RSC    

年代:1876

数据来源: RSC

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THE ANALYST. 149 AVA, OR, KAVA KAVA. Phwm. JournaJ, [3] No. 321, p . 149. AVA is the local name of the p@er methysticum, a shrub, about 6 ft. high, cultivated in Viti, Tahiti, Hawaii, the Society and Tongan Islands. The root and base of the stem have been introduced into France, as a remedy for gonorrhea, and it will probably be tried in this country ere long. According to M. Cuzent, the root contains an essential oil of a pale yellow colour, 2 per cent.of an acrid resin, and about 1 per cent. of a neutral crystalline principle called150 TEE ANALYST. kavahin, or methysticin, which is obtained in acicular crystals by crystallisation, from a concentrated tincture. Kavahin differs from piperin, and cubebin, in being coloured red by hydrochloric acid, the red coloiir fading on exposure to air into a bright yellow, and in being coloured by strong sulphuric acid, a purplish violet colour, which passes into green.Since neither kavahin, nor the resin are soluble i n water, and the infusion produces the characteristic effects of the drug, i t would appear probable, that the active principle is yet to be separated; kava in small doses acts as a stimulant and tonic, in large, it produces a silent and drowsy intoxication, and if used long for this purpose appears to cause a peculiar kind of skin disease. The root contains also nearly half its weight of starcb. A. W. B.

ISSN:0003-2654    

DOI:10.1039/AN876010149b

出版商:RSC    

年代:1876

数据来源: RSC