摘要:

INCLUDIXG THE PROCEEDINGS OFTHE “SOCIETY OF PUBLIC ANALYSTS.”A Monthly Journal for the information of those interested in the purity of Foodand Drugs, and in general Analytical and Microscopical Research.CONIIEETING OF SOCIETY OF PUELIC AIK~LYSTS ........ 121ON THE EXAMINATION OF SPIKITCS 1E:nmnI s Nr,~cosr.By Dr. Duprc .................................. 121OX ESTIMATION OF ETIIYr, ~IT1:ITE I N SPII~ITL%ETHERIS NITROSI. Cy Dr. nlnter. .............. 1%ANALPSLS OF FLOURS AND BREADS. By J. Cartrr Dell 1%EXANINATION. By G. W. Wgner ................ 133ON DR. XOETTSTORFER’S ?TII?TIIOD FOR BUT TI,:^.TENTS.SALE OF FOOD ASD nRCGS ACTI ~ l ~ V I ~ ~ Y S .....................COIUIESPOXDENCE .............AXALTSTS’ REPORTS ...........LAW EEPORT~ .................NOTES OF TIIF.MONTI~ ........Goorrs HECEIVED .............CHEMICAL PATENTS ...........AMIESDJIENT BILL . . 133 ..................... 134 ....... .: ............ 1:2j .................... l?G ..................... 137 ..................... 133 ..................... 139 ..................... 140COMMITTEE O F PUBLICATION OF THE SOCIETY’S PIiOCEEDINGS.J. MUTER, PILD., M.A., F.C.S.G. W. WIGNER, F.C.S.A. H. ALLEN, F.C.S.A. DUPRO, PH.D., F.B.S., F.C.S.C. HEISCH, F.C.S.AGSTTcACTORS.E. W. T. JONES, F.C.S.J. FALCONER KING, F.C.S.C. H. PIEGSE, F.C.S.A. WYNTER BLYTH, M.R.C.S.C. A. CAMERON, M.D.OTTO HEHNER, F.C.S.IMK. ;TA.CEKSON d& C0.965, BARBICAN, LONDON, E.C. (nearly opposite the Aldersgate Street Station o f the Metropolitan Railway),(J.ORME AND H. M. CAPNEB,)FINEST BERLINPORCELAIN.ScientificApparat n s,BOHEMIANGLASS.GRADUATEDI N STRU M E N TS.-HOFMA NN’SA PPA RA TUS.-ALSOELECTRICAL,G A L VA N IC,PNEUMA TICA P P A R A TUS,&c., dic. WEOLESALE AND EXPORT. rlPureChemicals.COMPLETESETS OFQUA L l TA TIVE,QUA N T l T A TIVE,VOLUMETRIC,AND ASSAYA PPA RA TUS.-PLA TTN E R’SBLOWPIPE.-EGGERTZCARBON. -A N DTHOMPSON’SFUEL TESTAPPARATUS.Makers of Apparatus to the Laboratories of the Inland Revenue, Royal Arsenal, Royal MilitaryAcademy, Science Schools, India Office, South Kensington, &c.Catalogues and Estimates sent on npplicntion, enclosing Business Card f o r Terms, &THE ANALYST.WORKS BY DRm MUTER, RI.A., F.C.S.,President of the Society o f Public Analysts ; Public Analyst for Lambeth, Southwark,Bermondsey, - Rotherhithe, Newington, and Wandsworth,Now rcacy, demy Svo, with copious Tables, price 7s.6cl.A N INTRODUCTION TO ANALYTICAL CHEMISTRY. or Medicaland Pharmaceutical Students.Now ready, royd 8v0, Second Edition, cloth, with Analytical Tables and copious Index, price 10s. 6d.A N INTRODUCTION TO PHARMACEUTICAL AND MEDICALCHEMISTY, Theoretical and Practical.6 ‘ The book is one of a very useful and original kind, and is brought up to the latest date, tests and‘‘ Amongst thc best chemical treatiscs of the day, and in many respects superior to m y that have yetprocesses published only a few months since being described in thcir proper places.”-CChemict!l News.been published.”-Pziblic Health.Third Edition, 600 pp., 8vo. Price 12s. 6d. A KEY TO ORGANIC MATERIA MEDICA.active principles of drugs.drugs.Analytical Chemists millfind this a concise and yet complete book of reference for the isolation and examination of tlieSpecial sppenclix on the microscopic characters of the starches in food a i dCopious index and qualitative courses or resins, &c.LONDON : BAILLI~RE, TINDALL RS Cox, 20, King William Street, Strand, and all Booksellers.By A, WYNTER BLYTH, M.R.C.S., F.C.S,, Public Analyst fop the County of Devon,NOW READY, crovn Svo, cloth, 12s. Gd.PRACTICAL CHEMISTRY (A Maiiual of).DETECTION OF Porsor\.s-Organic or Inorganic. With Tables and Diagrams.Analyst.”--Lancet.PART I: ANALYSIS OF FOODS-Flour, Bread, Milk, Butter, Cheese ; Tea, Coffee, Cocoa ; Alcoholic Liquids ; Condiments.PART I1 :“ ’ilrill be used by every‘‘ Stands unrivalled for completeness of information.”-Sa?aita~y Record.LONDON : UHABLES GRIFFIX 6t. Co., Stationers’ Hall Conrt.By G;. W. WIGNER, €,C.S., one of the Honorary Secretaries of the Society of Public Analysts;Public Analyst for Greenwich, Plumstend, and Woolwich Districts.Price, ONE SHILLING.SEASIDE WATER. An Examiiiation into the character of the Water Supply atthe Watering Places of England and Wales, being an abstract of a Series of Reports prepared fornnd published in the Sanitary Record during 1877-78, with Three Comprehensive Tables, giving Analysesof the Drinking Water at all the Sea-Coast Towns.KENT & Co., Pateriioster Row, London ; and at all Railway Bookstalls.E. C E T T Z & GO.,MANUFACTURERS OF BAROMETERS, THERMOMETERS, CHEMICAL ANDPHILOSOPHICAL APPARATUS O F EVERY DESCRIPTION.Dr.Franklin’s Apparatus for Analysis of Water. Dr. McLeocl’s Modification for Water and Gas.Professor Bischof’s Apparatus for Evaporation of Water. Dr. Sprengel’s i\’Iercurial Air Pumps of everyform. Water P ~ m p s for quick filtration. Dr. Mill’s Colorimeter.Drs. Russell and West’s Apparatus for Estimating Urea in Urine. Dr. Blackley’s Apparatus for Ditto.REGISTERED 321u’AMEL BACK URINE SEDIMXNT TEST TUBES.11 and 31, Brooke Street, Holboni, London, Wholesale and for Exportation, and Rose CottageGlass Wo~ks, Pratt Street, Lambeth.HARD OR SOFT WATER ?-THE PORTER-CLARK PROCESSFor the Softening and Filtration of Water in large quantities, within sinall space, at small cost.The rcmowl of the carbonates of lime axid mngnesia and iron frcm hard waters is the removal of(a) The cause of enormous waste of fuel occasiond by incrustation of steam boilers and pipes ;(a) The cause of imperfect cleansing 2nd puriEca:ion of and injury to 1ine:i and woollens iu laundries;( c ) The cauw of the frightful waste of soap, soda, and other alkalies by which those injnries are imparted and theimpurities retained.In County Asylums, Steam Laundries, and Manufactories * and for the TGWI Supply of Old and New Swindon and the Rsiln-nyWorks, the Porter-Clark Process is triating hundreds of thousands of gallons per day.The filtration is exquisite, a d cverytking arrested is removed daily.Patented by JOHN HENDERSON PORTER, C,E,, 1 & 2, Tudor St,, Blackfriars, London, E,C

ISSN:0003-2654    

DOI:10.1039/AN87904FP029

出版商:RSC    

年代:1879

数据来源: RSC

摘要:

THE ANALYST.PURE ACIDS AND CHEMICALSFOR ANALYSIS.KNOWLES & PHILLIPS,47, MINORIES, E.C.PRICE LIST FORWARDED ON APPLICATION.N.B.-References as to quality and price kindly allowed by severalleading Analysts already supplied.L. OERTLING,TURNMILL STREET,(Opposite Farringdon Street Station,)MIA~UFACTURER OFCHEMICAL, ASSAY & BULLIONBALANCES.Maker to the B a a of England, Assay Office of the Royal Mint, &c., &c. Bv ADDointment.COUNCIL NEDAL, 1851. FIRST GLASS JIEDAL, 1851 and 1862.THE SANITARY FLUID.ANTISEPTIC DISINFECTANT for Preventing Epidemics and Destroying InfectionsThis Fluid is a powerful Antiseptic, Disin-fcctnnt and Deodoriser, and from its linrmlcssiiess may be applied in any direction without any ill-effects,2nd with the best possible results.THE u PR,INCESS ALICE " CALAMITY.-The Sanitary Fluid was uscd at the Woolwicli Dor1,--, ard for Disinfecting over 600 bodies. The Clothing taken from the Bodies ail11 o ~ c r 500 Slieets 1 ~ 1 ~nlso Disinfected in large Cauldrons.Also the Building, Yards, Rrc., giving ilic greatcst sztisfaction to 11 c1)oclryard 2nd Parish Aut!iorities. The work wa3 carried out under the superinteiidmce of Alr. I-Ian~r~i:,SIR,--I beg to inforin you llintI consider your Disinfcctant, as applied in the Dockyard, both to buildings and clothing, after tlwremoval of the dead from the premises, very efficacious, and, from its cleanliness and abscncc of smc 11,wry superior to the Disinfectants in the form of powder generally used.-Faithfully jours, J .T.BARRIN~TON, Assistant Commissary General.For Asylums, Schools, Sanitary Authorities,Railway and Dock Companies, Workhouses, Shipring k c .Price 1s. pcr bottle ; 3s. 6d. per gallon ; large quantities at a cheaper rate, of the Sole Manufactu! 1 I.,The MAGIC FLUID for General Household Purposes, price 1s. 6d. per gallon. Write for PamphletDiseases, as supplied to the Royal Arsenal, Woolwich.TESTIJIONIAL.--" H.M. Dockyard, Woolwich, September 23, 1878.MI.. Harmer, Stratford, E."TV. J. HARMER, West Ham Lane, Stratford, E., or through Agents.with Tsstimonids, &c. NON-POISONOUSTHE ANALYST,THE ANGLO-AMERICAN TIN STAMPING COMPANY, LIMITEDSTOUJ3PORT, WORCESTERSNIRE.SEAMLESS, PLAIN, RETINNED, AND JAPANNED WARE,BIANUFACTURERS OF IMPROVEDDEEPDISH PAN.Ware by American Machinery.AlsoSole Licencees, unlter Letters Patent of August 7th, 1877, for t.hc Manufacture of WROUGHT-IRON MOTTLEDENAMELLED WARE in the TTnited Iiiiigdom.SAUCEPAN.V7ASH BASIN. ROUKD DEEPFL AJIIXG PUDDING PAN.nmx PAN.THE ANGLO-AMERICAN ENAMELLED WAICE is a NC \V articlc of Enamelled Krought-Iron Hollow-ware differing froillsimilar articles manufactured in Europe in the tenacity with which the enamel cling? to the iron upon which it & fused; in thebrilliancy of its glaze ; in the beauty of its ornamentation, due to the colonriug oxide supplied by the iron body, which in theenamelling process is absorbed by the glaze and distributed through i t in great variety of curious and attractive forms - in thethinness of the enamel, which insures its elasticity, whereby it the better resists fracture ; in the nbsohte puritp an$ 7ial.m-lessness of the enamel ingredients ; in its perfect insolubility under any action of hrat, acid, or water, in culinary operations,which insures ITS ABSOLUTE SAFETY IN USE, as the following certificate will testify :-[Corn] JOHNSON, MATTHEY & CO., Assayers and Rfe?ters to the Bank of England, Her Majesty’s Mint, &o.Asmy Offices and Ore Floors, Hatton Garden, London, E.C.CERTIFICATE O F ASSAY.February8th, 1879.We examined the sample ENAMELLED PANS FOR EXANINATION AND ANALYSIS, inarked as under, and find thofollowing to be the result :The pieces of enamel consist of a silicate of Sodn, Alumina, nnd Lime; entirely free from Antirnong and Lead.Theenamel, ’1.9 set upon thc pans, confirms our experiments -4th the sample of ennmel itself received separately. The pans havebeen subjected to the action both of acetic acid nnd dilute mineral acids, mhich they resist perfectly. We consider, therefore,that as ennmelled mare i t is thoroughly adapted for culinary and domestic purposes.For the Anglo-American Tin Stamping Company, Limited.JOHNSON, MATTHEY & CO.The Anglo-American Tin Stamping Co. will be glad to correspond with bqers regarding special sizes or patterns of goodsfor their markcts.Illus/i-ated Catalogue, Prices, and Terms furnished on application, 01’ througlr. any Merchant 01’ Factor.Export Liverpool Agants, HENRY NASH & Co., 12 and 14, Tower Buildings North, Water Street.Export London Agents, BROOKER, DORE Co., 2, Rood Lane, Fenchurch- Street;S I L X C A T E FAINbTIS THE BEST FOR ALL PURPOSES.NON - POISONOUS, INODOUROUS, ECONOMICAL.Specially adapted for HOSPITALS, INSTITUTIONS, &c.SILICATE PAINT CO., CHARLTON, KENT. LONDON OFFICE-107, CANNON STREET,LIVERPOOL OFFICE-32, SEEL STREET,W. E- BUTT 87; CO-,UNION CHEMICAL WORKS, DEBlVAMS RD., SOUTH BERMONDSEY, S. E.,MANUFACTURERS OFPharmaceutic, Photographic, and Pure Chemicals for Analysis,539 ec tar @rep A rat to it$+HYDROGEN PEROXIDE. FRUIT ESSENCES.IODOFORM. I FERRUGINOUS SYRUPS.SCALE PREPARATIONS,Printed for the Proprietors by JOHN DAVIS, Old Kent Road, S.E. ; and published by BAILLIJ~AE, TINDILL & cox, RingWilliam Street,, Stmnd, W.C., to whom all communiostions should be addressed

ISSN:0003-2654    

DOI:10.1039/AN87904BP031

出版商:RSC    

年代:1879

数据来源: RSC

摘要:

121 NOTE ON THE EXAIMINATION OF SPIRITUS ZTHERIS NITROSI, BY A. DUPRE, PILD., F.R.S. Rend bpforc tlrr Society of Pidlic Ana71~sts. cn Pt7b Jtinc, 1879. HAVING a t various times been asked for esplanatioiis as to the method I use for estimating tlie amount of nitrous ether, contained in a snrnple of Spiritus Etheris Nit8rosi, I take this opportunity of describing the mctliod 01x8 for dl. The principle of the method will be found in Duflos Apothekerbzcc7~, Edition 1867, p.251, and I have simply worked out tlic details a little more fully. For the present I confine myself to the analytical method, and must leave inany points of interest connected with tho subject to some future time. Spiritus atheris Nitrosi, as is mll lmo~m, is d&cted to be prepared (firit. PlLam.) by distilling a niixture of spirit, nitric and sulphnric acids a i d copper, and mixing the distillate obt'nined mitli n certain proportion of spirit.If a11 the nitric acid employed were used 1113 in tlie foormnt8ioii of nitrous ether, tlic proportion of sach contained in the finialiecl lxodnct, if ti\-o pints of spirit me added to the 15 ozs. of distillate, would snioimt to aborrt 6.5 per cent.In practice this result is, however, never obtained ; and, according to my experience, ve may consider a prodLlct containing 3 per cent. of iiitrous ether as fairly representing the B.P. preparation. In judging of the purity, or otherwise, of any given sample of Spiritus Bthcris Nitrosi, B.P., the particular method of manufacture adopted iii the preparation of the122 THE ANALYST.sample is, of course, perfectly immateilial ; as long as it fairly corresponds in strength to tlre B.P. standard, it must be considered ns of tlie nature, substance and quality cle man ci e d , 11 ow ever produce cl , Charactws. B,P, Transparent, very slight tinge of yellow. Specific gravity, 01845. Effervesces feebly, or not at all, when diaken with a little bicarboilate of soda, When agitated with a solution of salphate of iron, a i d a few drops of r;ulplruric ncici, it becomes olive browi or blaclr, If it be agitated with tvice its volame of saturated solutioii of chloride of calicum in a closed tube, two per cent.of its original ~ o l ~ m e szparate in tlie form of nitrous etlier, and rise to tlie surface of the mixture, Should give no precipitate with nitrate of silver ; absence of hydrocyanic and formic acids.A sniall qnantity poured on a little water, and ignited, should lem-e an aqueous solution, which gives no precipitate with iiitrde of Rilver ; absence of hydrocliloric ether, chloride of ethylene, &c. The cliloride of calcium test is not of much value. Firstly, because only those samples respond to it wliicli are iicarly of tlre proper strength, and iio iiiformatioir is gained as to the composition of those samples, from which nothing separates, escept of course that they are below tlie propcr strength.Secondly, because the mbstance separating though chiefly, is not by airy nienirs only, nitrous etheil. The iroii test may be used as a rough quantitatim test by using a sample of lmomii strength for comparison, and it offers a very ready means, before n magistrate for example, to sliow the cliaracter of any impugned sample.Estimation of Xitrous Ether. Ten cubic centimetres of the ether are introduced into a small flask already containing about 1.5 grammes of solid potash hydrate. The flask is closed with a well-fitting cork, gently agitated from time to time to promote solutioii of the potash, and left standing over night.Nest day tlie contents of tlie flask, more or less yellow according to the amount of aldehyde present, are waslied into an evaporating basin with 50 C.C. of water, a i d the mixture evaporated on n water-bath to about half or one-third. The remainder is allowed to cool, filtered tlirough a little glass wool into a beaker made up to 300 C.C.with water, 50 c,c. of diluted sulpliuric acid (1 in 4) are added, a i d the nitrous acid present determined by a, standard solution of permanganate. This standard solution is prepared by dissolving 8.475 grammes of pure permanganate of potassium (or its equivalent) in one litre water; 1 C.C. of this solution is equivalent to 0.01 grammes of nitrous ether, and therefore indicates 0.1 per cent of nitrous ether, if 10 C.C.of ether have been taken. The decolonration of the permangannte is rapid at first, gradually becoming slower. As soon as this is perceived not more than 0.6 C.C. are added at a time, and tlie process must be considered as at an end if the solution still shows a distinct pink or red colouration two minutes after such addition.For every cubic centimetre of permanganate solutioii then used, the Spiritus Btheris Nitrosi contains, at a maximum, 0.1 per cent. of nitrous ether. The solution still continues to decolourise peimanganate, though but slowly, and much more will have to be added before the colouration becomes permanent. I have however convinced myself, by many experiments, that all nitrous acid present is oxidised when the above indicated point is reached, No doubt other substances are Further Tests of Pzwity .THE ANALYST.125 Feb. 21, 1872 Nov. 15, 1873 April 23, 1879 Dec. 2, 1873 April 15, 1879 oxidised as well, and tlie process indicates more nitrous ether than is actually present ; but as the error is on the side of leniency, it is perhaps an advantage rather tliaij otherwise.By following out strictly the directions here given, it mill be found that duplicate analyses of a sample rarely differ more than 0.1 per cent. from eacli other ; while, with poor samples, tlie agreement is even more perfect. Sliould a sample require much permanganate, a,nd the solution, instead of becoming colourless, remains brown or yellow, more sulphuric acid must be added.If, instead of evaporating and filtering the alcoholic solution, it is at once diluted, acidified, and permanganate added, more of the latter will be required than in tlie former case. In good samples the difference is sometimes great, but in most poor samples it is but alight, and in such case this more rapid process may be adopted. I have also tried the process of adding at once an excess of permanganate, letting stand five minutes and estimating the excess remaining, but the results given are decidedly too high. Various other methods have been proposed for the estimation of the nitrous ether, but I do riot propose to enter into such, as the process given fulfils, I believe, all necessary conditions.It is stated in most works on the subject that iiitrous ether is rapidly decomposed and becomes acid.The latter statement is correct, as far at least as ordinary Spiritus Xtlieris Nitrosi is concerned, but the former is not in accordance with my experience. Spiritus Xtheris Nitrosi becomes acid mainly on account of the oxidation of tlie aldehyde it contains, while the nitrous ether present suffers but slow decomposition, at least when dissolved in spirit of sufficient strength.The fallowing analyses will illustrate this. Sample I. was prepared by myself on February 21st, 1872, auii lins been kept ever since in a glass stoppered bottle (white glass) of oiie litre capacity tvliicli it filled about half at first. About one half of the neck of the bottle was broken off early in 1872, so that the stopper does not fit very tightly since.The bottle stood on a shelf in the laboratory exposed to ordinary diffused daylight, but never to direct sunlight. On the bench below, and near to where the bottle stands, a Bunseii gas burner is frequently in use. Sample 11. was bought as a sample of Spiritus Btheris Nitrosi (Brit. PlLam.) from a well known wholesale house on December 2nd, 1873.It was contained in tlie ordiiiary pint bottle of green glass, and stood ever since in cz cupboard of the laboratory, or in other words chiefly in the dark. Both bottles were frequently opened, and small portions of ether taken out in the intervals between tlie analyses given :- ,836 84.8 per cent. b. w. 0.10 2.00 *839 83.6 9 , 9 , 0.90 1-98 ,844 81.7 9 9 I , 0.85 0.89 ,824 89.5 $ 3 9 , 1.19 1.35 *847 80.5 9 9 9 9 1.38 0.96 No.of sample. We Corresponding Total acid free Real gravity. alcoholic strength. as acetic acid. nitrous ether. I I Date of I Specific I examination, see, therefore, that even uuder somewhat unfavowable conditions the124 THE ANALYST. decomposition of the nitrous ether proceeds but slowly, and the plea sometimes advanced by chemists that the sample of Spiritus Btlieris Nitrosi obtained at their shops, and found wanting, had been kept for some time and had decomposed, may safely be set aside as untrue.Iu conclusion, I give the analyses of a number of samples, every one of which mas bought as Spiritus Btheris Nitrosi (Brit. Phat*m.), and should therefore have had a sp.gr. of 0.845, and contained about 3 per cent. of nitrous ether. All, except the last, mere, however, bought before tlie present Sale of Food and Drugs Act came into operation. The last sample ~7as supplied to the Westminster Hospital early in April, 1879. The bottle coiltailling it, a Wiiichester quart, was labelled ‘ I Spiritus Btheris Nitrosi, Brit. Pliarm., sp. gr. 0.845.’’ The bottle was quite full, and had not been opened at the Hospital, the stopper being still tied over with bladder when I took the sample on April 23rd, 1879.Specific. Corresponding Total free acid Real gravity. alcoholic strength. as acetic acid. nitrous ether. 0.908 . . . . 54.05 per cent. b. w. 0.42 per cent. . . 0-23 per cent. 0.913 .. .. 52.0 .. .. 0.39 .. .. 0.19 0.851 ,. .. 79. .. .. 0.09 ,. .. 0.06 0,892 .. .. 61.5 .. a . 0.32 .. .. 0.38 (3.854 .. .. 77.7 .. .. 0.47 .. .. 0.44 0.936 .. .. 41.8 .. I . 0.41 .. .. iP10 0.851 .. .. 79. .. .. 1.14 .. .. 1.30 0.928 ,. .. 45.6 .. .. 0.33 .. .. 0.25 0.852 .. .. 78.5 .. .. 0028 .. .. 0-07 0.848 .. .. 80. .. .. 1.28 .. .. 1.40 0.849 .. .. 79.7 .. .. 0.96 .. .. 0.52 Mr. Hehner suggested that the direct addition of iodide of potassium would give a much fairer measure of the quantity of nitre present. He would add acetic acid and iodide of potassium, which both Dr. Muter and Mr. Wigner said they thought was a very good idea.

ISSN:0003-2654    

DOI:10.1039/AN879040121b

出版商:RSC    

年代:1879

数据来源: RSC

摘要:

124 THE ANALYST. ON THE ESTIM.ATION O F ETHYL NITRITE IN SPIRITUS ETHERIS NITROSI, B.P. BY JOHN MUTER, PH.D,, F.C.S. I HAVE been in the habit of using a saponification process for this spirit, but I work in n manner somewhat different from that used by Dr. DuprB, which I think possesses several advantages. (1). Decinormal solution of hyposulphite of soda (sodium thiosulphate), m d e exactly according to the directions of tlie British Pharmacopmia, each C.C.of which = .0127 free iodine. Solution of potassium permangnnate, containing 3.175 grammes per litre, and checked to balance the ‘( hypo.” solution, by adding excess of saturated solution of potassium iodide to 100 c.c., and then seeing that the iodine set free exactly requires 100 C.C. of 6chypo.” for complete decolourisatioii, starch paste being added as an indicator towards the end of the process.I first take the specific gravity of the saiuple at GOQ Fnlv,, and I then measure out The solutions I use are : - (2).THE ANALYST. 125 10 C.C. of the spirit for analysis. This I digest with sufficient potassiluu hydrate in a small strong glass flask, closed by a cork, through which passes a bent delivery tube, dipping under a column of mercury in a test tube, of such a height as will enable me to lieat gently on a water-bat11 u d e r pressure without bursting the flask.This point is ascertained by a blank experiment, during wliich the flask is wrapped in a cover to prevent accident ; and oiice arrived at, the same flask and mercury column are always employed.After digestion under pressure witli frequent agitation for some time (an lioru. being usually ample), water is added, aucl the contents of the flask eraporated iii a basin until no smell of spirit is perceptible. The residual liquid having been rendered just w x t r d with sulphuric acid, is filtered into a flask containiiig 75 C.C. of perrnan- ganate solution, previously dilated to 200 C.C.with water and acidulated with 20’ C.C. dilute sulphuric acid (1 in 3), and the flask having been corked is left for half an hour. At the end of that time excess of saturated solution of potassium iodide is added (which should produce a clear deep orange solution), and the whole brought under a burette containing the hyposulphite solution and titrated. The number of C.C.of ‘‘ hypo.” used is deducted from the number of C.C. of permnnganatc put in, and the differciice mdtiplied by e00375 gives the amognt of ethyl nitrite in the 10 C.C. taken for analysis, aiicl if tliis be multiplied by 100 and divided by 10 times the specific gravity of tllc original spirit, the answer will be tlie percentaige of etliyl litrite by wcight. In ~ ~ r l i i l l g with spirits of ~ulkiiox711 strength it is advisable to put only 20 C.C.of permanganate into tlie flask at first, diluted and acidulated as directed, and then if all the colour disappears under five miiiutes, to add 5 C.C. more at a time, until a permanent colour is obtained, lasting five minutes, .when the addition of another 5 C.C. will suffice before setting asidc for the lialf hour.In a good spirit it is sufficient to take 5 C.C. for analysis, and to usc 35 to 38 C.C. permaiigaiiate. I am the more inclined to believe in the accuracy of this metllod, because I have found, by expiment, tliat the action of potassium nitrite on permanganate is iiot thoroughly trustworthy under lialf an hour, I3 thy1 nitrite is, however, much uorc mpiclly affected, and I am at present cngagel on a process whereby saponification is eiitirely avoided, aiid the whole thing docs not occupy more than ten minutes.Tj’atil I publish this, I reserve my results on tlie actual constitution of the spirit, alld the loss it uiidergoes by keepiizg. I am not at all clear that we should depend entirely on the etliyl nitrite alone for the real value of tliis rncdicine, and my other method depends on the estimation of tlie aldehyci and other boclies present in the article when pyoperly made according to the official process.The following are some analyses of pure spirits (specially made for ine by Mr. Phillips-of Messrs. Iiiioivles and Phillips-strictly by the B.P. process, and answering the gravity and separation tests of that authority), which were recently performed by one of my advanced stde11ts, MY. Lather Scammel1:- Saiiiplc No.1 contsbined 3.03 ethyl nitritc 7 7 7 9 2 7 7 ‘L.91 7 , 9 7 7 , 7 , 3 - 7 2.96 ? I 7 9 3 7 ,, 4 7 7 2-35 7 , 1 9 9 , 9 , 5 3 9 2.39 $ 3 9 , 9 7 ,9 7 7 2-93 ,, ,,126 THE ANALYST. I always prefer prefer to do a blank experiment, using 20 C.C. pure rectified spirit, and the same weight of potassium hydrate as I use to the ether, and check it side by side with the sample experiment. In practice I use about two grammes K H 0 aiid add 10 C.C. of rectified spirit, which sicis its solution and helps saponification of the ethyl nitrite. I have also often used, for the sapoiiification, a small flask fitted to a well cooled upright condenser, a i d worked at the boiling point ; but I find the simple arrmgement above stated does just as well.

ISSN:0003-2654    

DOI:10.1039/AN8790400124

出版商:RSC    

年代:1879

数据来源: RSC

摘要:

126 THE ANALYST. ANALYSES OF FLOURS AND BREADS. BY J. CARTER BELL, F.C.S. llentl btforcz tlie Society of Public Analysts, o n 4th Jiuae, 1879. SINCE December, 1877, I have been engaged upon the analyses of flour and bread, -with the object of satisfying myself, by actual experiment, as to the quantity of phosphate of alumina contained in those two essential articles of food. Like many other chemists I was under the impression that the quantity of alum calculated from the phosphate of alumina found in a four-pound loaf was very small, but since I have analysed over one hundred samples, my views have been considerably modified.I t is with diffidence I bring tliese analyses forward, as the Institute of Chemistry seems completely to ignore the original work of Public Analysts, and is groping hopelessly in the dark ; whereas, if 6ome guidance were accepted from men who have had practical experience, the Institute might gain some information upon the analysis of food, of which it confesses itself at the present time ignorant.I n the Conference upon Milk no mention was made of the labours of Mi*. Wanklyn, myself and others. In my experiments upon milk, I had 183 cows milked in my presence at various times and seasons ; the milk from the majority of these cow8 was analysed separately, and all information, such as food, age, colour of cow, &c., was obtained, so that accurate data could be registered for fixing a milk standard, which I flatter myself I have obtained, and now decide according to that standard.It may be that this quiet ignoring of work accomplished, may arise from a modest desire of the Institute that men should not labour and the Institute enter into their labours.In the following analyses, which for the above reasons I forward to the Society of Public Analysts, I have been careful to obtain samples of flour and bread of acknowledged purity. Many of the sainples of flour were obtained from Mr.Render, of the Crown Flour Mills, Salford, and of Mr, Moss, of West Gore Street Mill, Sttlford ; they, knowing what I required the samples for, were most careful in supplying them as pure as they could possibly be. My method of analysis was that proposed by Dr. Duprh, and modified by Mr. Wanklyn. Before incinerating flour or bread, I always thoroughly dry the samples, as I find they burn away in a much shorter period, and no unpleasant vapours are evolved.Much has been said and written about the logwooci test and its uncertainty, but according to my experience, if the solution is prepared according to the directions given by JIr, Horslcy, it works admirably. I trtke 16 gfiiumes of freslily-cut logwood, andTHZ ANALYST. 127 digest in cold methylated spirit for about eight liours, with an occasional slialie of tlie solution ; at tlie end of tlie eight hours the clear liquor is poured off.For bread, about 10 grammes of the crumb are taken, and a mixture consisting of 90 C.C. of water, 5 C.C. of the logmoocl solution, mid 5 C.C. of a saturated solution of csrboiiate of ammoiiia is poured over the bread in a porcelain dish.If tlie bread coiltalus alum, a dark lavender blue soon inalres its appearance. The bread is washed and dried ; if the blue lavender colour remains, I always fiiid that alum is present. For flour, Iweigh out 10 grammes, mix mitli 10 C.C. of water, then add 1 C.C. of log1~700cl solution, and 1 C.C. of carbonate of ammonia solution ; if tlie flour is pure, piiilrisli colour is obtained ; wliereas, if alum is preseiit, the pink is changed to lavender, and I have detected alum in flour in so small a quantity as 3 grains to the four-pound loaf.By having a standard solution of alum mid ndciiiig it to flour, it will be at once seen wliether tlie logwoocl solution is fit t o use. I have liad mine nlztde LIP for several months, aiid it is still good.Until I read Dr. Diip8's paper, I liad not paid muel1 attention to the silica in flour and bread ; but I now see that it forms a very important item in the analysis, because whenever I obtained a high silica, I looked for a high pliosphate of alurniiia. In all cases of flow and bread; I have cslcdated the silica and alum in grains to the four-pound loaf. Tlie crowii is tlic trade marl< of the firm; five crowns beiiig the best flour, and made from the centre of tllie grain of the choicest wheats, while the lower crowns are of inferior qiiality.Thus, t'lie price of five crowiis is 48s. a sack, while one crowii is 34s. ; the intermediate ones are between the t v o cstremes. These floiirs vere made from a mixture of English niid Californian wheats. No. 2 C L ' O T V ~ lias a very high phosphate of alumina, eqtialling about 16 grains of alnin to tlie four-pound loaf.I tliought that there must be some mistake ns regards this flour, tvliicli led me to make further csperiinents. The flour The first lot of five flours I obtained from Mr. Render, in 1877. was andysed four times, with the folloming results :- Grains of Silica to 4 lb. loaf. No.1 Silica e l 0 0 . . Phosphate of alumina -021 .. 21 2 ,, -102 .. 9 , -017 .. 214 3 ,, -105 .. 9 I -020 .. 22 4 ,, -109 .. 9 , so84 .. 22; These results do iiot agree so well as could be mishcd, owing, I Grains of Alum to 4 lb. loaf. .. 152 .. 123 .. 15 .. 18 expect, to the mechanical mixture. I cannot believe that this ainouiit of alumina is n coiistitueiit part of tlie grain, but must arise from imperfectly cleaned wheat.Tlie large percentage of silica is an important item to be noticed in the analysis; any chemist using moderate care could not return this flour as adulterated with alum. Five 1iound.s of the flour were made into bread. Tlic analysis of the bread crumb gave :- lfoistnre . . , . . . . . 45.000 per cent. Silica .. .. . . .. -066 ,, Phospliate of iron .. . . . , -007 ,, Phosphate of aluiniiin , , . . -011, OY 11$ grains alum to the 4 lb. loaf. I t is my practice in bread analysis, to deduct 10 grains of ahin from the total quantity calculated from the phosphate of alumina fouiid in a four-pound loaf. So that, on the above bread, when the ten grains are deducted, the quantity left would be128 THE ANALYST.80 small, that takiiig iiotice of tlie high dim, this bread could iiot be retuned as containing alum. Out of the one hundred samples I have examined, this is the only iiistance of a loaf which contaiiis 11 grains of alum. Two other flours-one marked Russian, a,nd the other Ghirklt-gave high alumina, but at the same time high silica : these were coarse flours, such as tt good baker would not like to use, The analyses of these were as follows :- 100 parts contain Bussian.Ghirka. Moisture . . . . . . . . 13.86 . . . . . . 8.280 Ash . . . . . . . . . . *58 . . . . . . -692 Silica . . . . . . . . . . *055 . . . . . . -062 Phosphate of iron . . . . . . *007 . . . . . . -007 Phosphate of slniiiiiin . . . . -01G . . . . . . -01G 23, lbs. of this Russian flour were made into bread ; it made a very coarse browii losf, and the analysis was as follows :- Moisture .. . . . . . . . . 42.700 Silica . . . . . . . . . . . . -034 -Phosphate of iron . . . . . . . . 0006 Phosphate of alumina , , . , . . a010 or 10 grains to 4 lb. loaf. Here, again, the deduction of the 10 grains leaves nothing to return as alum, These I consider extreme cases : for it will be seen by the great number of samples of bread which I have bought from shops in Salford, not one reaches 10 grains of alum to the four-pound loaf.Some of the flours in the following list require a little explanation. No, 1 Crown has a high silica ; this analysis was made in 1877, but while writing this paper I have estimated the silica again, a d the mean of the two gives 0077.No. 2 I have already explained, I have tried to obtain some more of the same kind of flour but have not succeeded. I n June, 1877, I analysed another sample of 2 Crown Flour- Silica . . . . . . . . . . -009 Phosphate of iron . . . . . . . . -003 Phosphate of alumina . . . . . . 0008 In March, 1879, another lot of 2 Crown gave- Silica . . . . . . . . . . -021 Phosphate of iron .. . . . . . . -004 Phosphate of alumina . . . . . . -010 From these, and other samples, I am inclined to believe that the sample of 1877 was an exceptionable one. I have found that fine flours are less likely to contain high silicas a d alnminas mheii they have been prepared by what is called the c 6 high grind process :” by this a central portion called “ extract ” is taken from the wheat, by the millstones being kept further apart than by the old process of grinding; thus leaving a large amount of flour adhering to the bran, which being again re-ground gives a poor flour called ‘‘ bran flour,” which is liable to contain more alumina than the extract flour, in consequence of being subject to a more severe treatment between the stones.extract ” and the bran flour there are several intermediate qualities of semolina flour, from which Some of the choicest flours now in use are produced, Between theTHE ANALYST.129 The American spring wheat lias a liigh silica, -054; this was estimated in 1877. Residue Flour is called in the trade (' inferior re-grounds.'! Brnlc Flow. This is flour that lies closest to tlie skin, wliich lias been removed by second grinding, a d only produced by the high giind process. This is flour drawn from the stones by the drauglit which keeps the stones cool, It is liable to contain a larger quantity of alumina than found in ordinary flour.Within the last few days tlie analysis has been repeated, with the same results. Rxhaiut E'loitr. No. 18.-From a country mill in Cheshire.Nos. 19, 20, 21.-Made in Salford by Mr. Moss, by the old process of grinding. Nos. 26, 27.-Bouglit from bakers, in Salford. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13, 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24, 25, 26 I 27. 28. 29. 30. 31. 32. One Crown Flour . . . . . . . . . . Two ,, ,, . . . . . . . . . . Three . . . . . . . . . . . . . . Four , . . . . . . . . . . . . . Five .. . . . . . . . . . . . . White English Wheat, 1877 . . . . . . Red ,, . . . . . . . . American Spring Wheat . . . . . . . . .. Red Winter Wheat . . . . . . Empress Hungarian . . . . . . . . Residue Flour, from 1, 2, 3 mixture of Crown . . Bran Flour . . . . . . . . . . . . Exhaust Flour . . . . . . . . . . Russian Flour . . . . . . . . . . Egyptian ,, . . . . . . . . . . Ghirka, ,, .. . . . . . . . . Semolina ,, . . . . . . . . . . 9 , 100 parts contain Grains Grains Phos- Phosphate of of phate of Silica to Alumto Silica. of Iron. Aluminn. 41b. loaf. 41b. loaf. Moisture. Ash. 13.02 -625 *077 -0107 418 16& 134 12-62 '604 *lo5 *0056 ,0204 22 16 12.46 -52 .024 -003 *009 5 7 12-08 -488 *012 *003 ,005 2+ 4 11-82 -484 -010 .002 ~004 2 3 13-62 *438 -020 ,004 -010 42 7f 12.62 -492 -056 ,006 *013 112 10 13.06 -380 *014 -002 -007 3 54 11-44 -368 .010 *001 *002 2 14 9.48 *476 ,028 *010 .010 53 7g 8-92 *488 0029 0009 .012 6 9% 11.35 ,610 ,0268 -0058 -011 5& 84 13.86 -680 ,055 ,0072 -0162 ll* l2A 12.98 0700 ,020 *0045 -0059 4% 4& 8.28 *593 ,062 *0067 -0163 13 12* 7.02 ,440 .011 -0008 .0062 22 44 9.84 ,448 ,015 905 -007 6 51- Flour, English a d foreign wheat, 2 English,) 3 foreign; the foreign principally Californian! 2'oo '400 '020 *Ool 'Ool 4;3 9 Straws.made in Salford . . . . . . . . 13.22 -6'72 so10 00021 -0023 2 12 Coarse Flour, or seconds, containing bran . . 13.92 1.44 -052 -0032 *0038 11 44 White Flour, made in Salford . . . . . . 13.02 *680 -023 -0032 *0018 5 14 Peerless Flour, made by Banaman, Sherman and} 13.30 .500 ,ooo25 .ool 2* if.Go., Rochester, U.S. . . . . . . . . Rochester, U.S. . . . . . . . . . . Gilt Edge, made by Chase, Bristol and Bide,} 13.04 ,516 .020 ,00027 .ooo8 4% CalifornianFlour . . . . . . . . . . 12.60 -480 *021 ,0064 *0078 44 6% WhiteEnglish, 1878 . . . . . . . . 14.90 *368 -021 -0035 -0049 4& 32 -0005 W15 1 12.80 -0335 . O M -009 7 7 per cent, Red English, 30 per cent.Califor- 12.80 ,260 *023 00037 -0087 4g 62 Two Crown Flour, total produce of wheat-40 nian White, 30 per cent. Canadian White . . ~- BranFlourfrom Two Crown Mixture . . . . 12.30 -76 .046 -007 -016 9& 124 P. A. Campbell, SanFrancisco . . . . . . 12.200 -300 -016 *003 -004 31 3 J. F., Salem Mills, United States.. . . . . 10,320 -448 -012 901 0004 24 3 Two Crown Flow, less 5 per cent.Bran Flour . . 13.00 -26 ,0214 -004 -0106 44 8$ . . . . 10*000 ,520 -013 ,002 .001 2% 3130 THE ANALYST . The following thirty-two breads were bought from bakers in Sslford. and the crumb of the bread was taken for aiialysis- 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 . 9 . 10 . 11 . 12 . 13 . 14 . 15 . 16 . 17 . 18 . 19 . 20 . 21 . 22 . 23 . 24 . 25 .26 . 27 . 28 . 29 . 30 . 31 . 32 . Bread .. 3 9 3 9 1) .. 9 9 .. 11 ¶ > .. 9 1 .. 1 ) .. 3 1 7 9 $ 9 .. $ 9 .. .. 1 7 .. .. .. 11 .. .. a 9 .. 91 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . Moisture . 46-10 45-00 45.50 40.30 40.50 46.00 44.50 46.00 46-00 45.50 46.50 46.00 46.00 46.00 46.20 47.50 46.50 49.50 47.50 46.50 47.20 46.50 45-50 46.00 45.30 46.20 44-50 44.00 45-60 44.50 44.00 46-00 Pho sphatc Silica . of Iron . *014 -0010 *033 -0013 -019 *0013 -010 -0013 -012 *0010 -015 *0013 *017 -0016 *014 * 0018 -013 *0010 . 039 . 0029 -014 . 0013 -018 *0010 -037 .0013 ~021 -0026 * 013 . 0032 -019 *0005 . 012 . 0013 . 016 *0018 *021 -0016 0016 -0018 *029 *0018 -0205 -0018 *024 -0018 -015 -0026 -015 -0040 . 019 0032 a019 -0040 . 020 *0026 *012 *0016 a019 *0018 -017 00026 . 025 . 0018 Phosphate of Alunlina . -0030 -0067 *0037 so022 . 0030 -0046 . 0034 SO082 -0040 *0031 -0052 -0050 -0067 *0026 -0028 -0045 -0043 *0032 -0064 -0037 *0042 -0068 -0064 -0066 *0052 ~0044 *0038 .0058 -0044 *0048 *0042 *0058 Grains of Silica to 41b . loaf . 3 7 4 2 ;i :+ 83$ ;2 F 32 32 72 4& 24 34 44 4f 5 3 3 4 4 44 7 The following eight breads were made under my own superintendence from flour which I had analysed. and wkich appear in the table :- 100 parts contain Grains of Grains of Phosphate Phosphate Silica to Alum to Moisture .Silica . of Iron . of Alumiua . 41b . loaf. 41b.loaf. Bread made from One Crown Flour . . . . 45.00 -051 . 001 '003 103 3 Three .. . . . . 4000 *019 00026 -009 .. .. Four 1 9 . . . . 38.00 -016 . 005 *004 34 4 .. 11 Tmo 11 . . . . 45.00 -065 4067 . 011 1; .. l l Five .. 36.50 -013 -0046 -0022 22 t * 9 :$ 9 9 .. .. White Engzsh Whea" .. 36.90 015 -003 so04 3 9 1 91 91 Red ..39.50 0020 *0021 -0053 .. Russian Flour . . . . 42.*70 -034 . 010 -0053 These breads were made by Mr . Render. from samples of flour ground by himself . The bread in most cases was tlhd with logwood. but gave no indications of alum . 4 8 Bread 50 per cent . English Red. 50 per cent.} 42.50 Canadian White . . . . . . . 019 . 0032 . 0082 .. Pure White Canadian . . . . . . 42.50 -021 -0018 -0035 44 34 Canadian Semolina 43.90 -008 00026 -0032 13 32 ... . . . . . 3 9 .. Californian Flour . . . . . . . . 43.50 . 023 . 0072 *0100 4Q 10 .. One Crown Flour . . . . . . . . 46.50 *019 *0035 -0031 4 3 .. Four . . . . . . . . . . 45.00 *008 *0053 *0053 13 54 The following are some instances of pure samples of bread. which when treated with the logwood solution gave a very suspicious blue colour when met. and caused me to think that durn T .Y ~ S present. but after washing and drying the sample there was not the slightest trace of blue colour ; a i d I sliould strougly urge all analysts to dry the .. 50 per cent . English Red. 50 per cent.} 43.00 . 015 . 0026 . oo9 Semolina . . . . . . . .THE ANALYST. 131 samples of bread before giving a decided judgment upon the presence or absence of alum.I t is now my habit to enter in st note-bDok my opinion as regards a sample of bread when treated with tlie logwood solution before taking further steps, to show how easily one uay be deceived by giving a verclict without trying tlie logwood test. 1 had two samples of bread from the County of Chester, a few days since. The logwood tmt was applied as usual.I entered-" The bread has a bluisli colour, and I slioulcl tliiiili there will be about 8 grains of slum to the four-pound loaf," The analyses of the samples were- ;: : 48.1 -008 -002 *006 47.5 *012 -004 ,004 When the bread was clry there was no blue colour. The following are some samples which I have analysed, thinking from the logwood test that they contained alum; if I had waited until the logwood bread was dry, I should then have seen that I had been mistaken, but having begun the analysis I thought it would be interesting to finish.I have arra'nged them in order of tlie silicas. Phosphate Phosphate Grains of Silica, Gi+ains of Alum silica,. of Iron. of Alumina. to 4 lb. loaf. to 4 lb. loaf. *008 .. .. -002 .. .. -005 .... 22 .. ,. 5 *012 .. .. -004 ,. .. *004 .. .. 3& .. ,. 4 ,018 .. .. .003 .. ,. *005 .. .. 5 .. .. 5 0020 .. .. ,004 .. .. -003 . . .. * . .. 3 0027 .. .. -006 .. .. 0010 .. .. 74 .. .. 10 0031 .. .. -004 .. .. *009 .. .. Sg .. .. 0 ,031 .. ., *006 .. .. *010 .. .. 8+ .. .. 10 0031 .. .. -004 .. .. -009 .. .. 8& .. .. 9 *039 .. .. -003 .. .. -008 .. .. 11 .. .. 8 a023 .... *005 .. .. -010 .. ,. ? .. .. 10 B r e d containing alum- 0008 .. .. ,003 .. .. -026 .. ., .. .. 26 -015 .. .. -004 .. .. 4 2 5 .. .. 3 .. .. 25 so16 .. .. *004 .. .. -034 .. .. 4& .. ,. 34 -017 . a -003 * . '037 .. - 6 42 .. .. 37 -020 .. .. *004 .. . . 0040 .. .. 5+ .. .. 40 -020 . , .. -005 .. .. -024 .. .. * . .. 21 -022 .. .. -003 .. .. -026 .. .. ? .. .. 26 .029 .. ..-003 .. .. ,041 .. ,. .. .. 41 *030 .. .. *005 .. .. *037 .. .. :$ .. .. 37 -030 .. .. -005 .. .. -028 .. .. 84 ,, ,. 28 -033 .. .. -004 .. .. -015 .. .. 9a . . .. I5 -037 .. .. -004 .. .. -021 .. .. lob ,. ,. 21 *040 . . . . *005 . . . . *032 . . . . l l a . . . . 32 -041 .. .. ,004 .. .. *015 .. .. 113 .. .. 15 *041 .. .. -008 .. .. -013 .. .. .. 13 ,046 .. .. -003 .. .. ,020 ..:: .. .. 20 I thought it would be interesting to trace the alumina from the wlieat, through tlie various products. I therefore procured some wheat from Mr. Render,' and he prepared the bran, flour, &c., specially for me. Contained in 100 parts Grains of Grains of Alum to Moisture. Ash. Silica. of Iron. of Alumina. 41b. loaf. 41b.loaf. Phosphate Phosphate Silica to Eiiglish Wheat grown ttpon chalk soil * 9.512 1.720 -00 & -013 10 Sharps, 8& ,, One Crown Flour, 26 per cent... 13.20 *500 *008 *003 *007 1Q 5& Four ,, 45 ,, .. .. 13.28 .368 ,011 .002 ,006 2& 45 ,. .. ,, 12.720 2.000 .034 -007 'OX -017 437* 123 12+ Bran, 184 per cent. . . . . . . 12.400 5.640 -206 -046 * The samplc of d i e a t hail been lyiiig i u the iiiiller's office for soiuc days.This J;ill acconiit for the low moisture.132 THE ANALYST. Mr. Penney, on page 80 of the Chcnzical News for this year, states--"It has recently become apparent that the attempt to fix upon a standard must be abandoned." My labours, which have extended over fifteen months, duri11g which time I have examined nearly two liundred samples, lead me to rz more hopeful conclusion, and appear to prove that a s t a d d can be fixed ; and a chemist with common judgment ought to be able to determine whether any excess of alumina is due to adulteration, or to other causes.I t may please the public to know that out of many hundred samples I have only found one case of flour adulterated with alum. Dr. DuprB said he found the logwood often gave a re-action, but the colour dis- appeared when drying; he was in the habit of drying in an air-bath, and that he believed was the original direction when this tesl was first brought prominently forward. Not unfrequently flours might give a suspicion, but dry them and it disappears at once.One point in Mr. Bell's paper struck him as being of value, viz., that the bran in flour should be estimated, and if possible the bran in the bread, because bran contains a large amount of silica and very little alumina. He had just had nine samples of bread to analyse.One gave Che logwood reaction and contained alumina equivalent to 42 grains of alum per 4 1bs.-the silica came to 17 grains per 4 1bs.-so that he reported it to be adulterated with about 24 grains of alum. Dr.Muter said that, with reference to the elucidation of the silicate question by ascertaining the amount of bran present in the flour, he should propose an attempt at the estimation of the cellulose, by a rapid process such as he had tried some years ago on a drug containing only a minute quantity, and which consisted in finding the amount soluble in ammoniacal cupric oxide solution. He prepared some of the re-agent of which he took two equal parts by weight, and placed them side by side ; into one he put the impure cellulose to be estimated, and, after proper maceration, he filtered both fluids through equal weights of a mineral filtering medium, and then evaporated both and dried at the same temperature, and for the same time. The increase in the one residue over the other was supposed to be cellulose; and his impression was that the process promised well, but he intended to try it again on this flour question at his first spme time, Mr. Bell Bad noticed a fact about the logwood test which was quite correct ; namely, that a colour sometimes appears while wet, but disappears on drying. In such cases he had noticed that there was usually sufficient alumina to calculate to about 12 grains a81um per loaf, and an excess of silica such as to prevent its being considered to be really alum. He remembered that in the cellulose process he spoke of, much depended upon the temperature at which the maceration was done, but the exact particulars he had now forgotten.

ISSN:0003-2654    

DOI:10.1039/AN8790400126

出版商:RSC    

年代:1879

数据来源: RSC

摘要:

132 THE ANALY8T. ON DR. KOETTSTORFER’S METHOD FOB THE EXAMINATION OF BUTTER FOR FOREIGN FATS. BY G. W. WIGCNER, F.C.S. SINCE the publication of this process in the ANALYST laat month, I have carefully tested it on various samples of genuine butter and of adulterated butters, and other fats, such as dripping or lard, and find it not only a quick and liondy process, but a reliable one. The point of neutrality is very sliarply indicated by the phenol-yktalein, and byTHE ANALYST.133 working on moderate quantities, say 50 grains, or thereabouts, of tlie filtered fat it is possible to obtain a mnch greater relative degree of accizracy than by the determination of the fatty acids. I fiiid it advisable, after saponification, to dissolve the soap in hot water and titrate mliile still hot ; by this meaiis the precipitation of the fatty acids during the process of thation is prevented, and the finish of the neutralization seen more distinctly.I find that my samples of butter require a slightly larger percentage of potash to saturate them tliaii the samples iiivestigated by the author of the process, but the difference is small, and there is about 3.0 pcr cent. difierence between the potash required by any fat I have yet tested, and that required by a genuine sample of butter.

ISSN:0003-2654    

DOI:10.1039/AN8790400132

出版商:RSC    

年代:1879

数据来源: RSC

摘要:

THE ANALYST. 133 SALE O F FOOD AND DRUGS ACT AMENDMENT BILL. THIS Bill, a copy of which nppeared in our last number, has passed the House of Commons, and is iiow before the House of Lords. The Commons have amended tlie last clause by limiting the provision for serving a suimnoiis within 28 days from the time of the purchase of an adulterated article, to (‘ the case of a perishable article ” only, and the following new clauses have been introduced :- “Any medical officer of health, inspector of nuisances, or inspector of weights and measures, or any inspector of &-market, or any police constable under the direction and at the cost of the local authority appointing such officer, inspector, or constable, or charged with the execution of this Act, may procure at the place of delivery any sample of any milk in course of delivery to the purchaser or consignee in pursuance of any contract for the sale to such purchaser or consignee of such milk ; and such offices, inspector, or constable, if he suspect the same to have been sold contrary to any of the provisions of the principal Act, shall submit the same to be analysed, and the same shall be analysed, and proceedin@ shall be taken, and penalties on conviction be enforced in like manner in all respects as if such officey, inspector, or constable had purchased the same from the seller or consignor under section thirteen of the principal Act.‘‘ The seller or oonsignor or any person or persons entrusted by him for the time being with the oharge of such milk, if he shall refuse to allow such officer, inspector, or constable to take the quantity which such oacer, inspector, or constable shall require for the purpose of analysis, shall be liable to [I pen’alty not exceeding ten pounds.” ANALYSES AT A DIsCouNT.-At the Breconshire Quarter Sessions, a letter was read from the Local Government Board, referring to the county having made no arrangements for obtaining samples for analysis by the Public Analyst under the Sale of Food Act, and requesting that the proviiions of the section of the Act bearing upon the point might be brought before the Court.Sir Joseph Bailey asked what expense it was to the county, and what good it was. Mr. Lloyd said the analyst was paid by the year, and not by the case. Sir Joseph observed that they mere perfectly content with their food and drugs.The report of the County Analyst was read as follows :-‘‘ I have the honour to report that I have not received during the past quarter any sample of food, drink, or drugs.” The Chief Constable was requested to take a number of cases, and ascertain what was the amount of remuneration. DECLINING TO APPOINT AN Ax&%T.-At a recent meeting of the Leominster Town Council a letter mas read from the Local Government Board, calling attention to the €act that they had already sent two communications, asking if the Council had further considered the subject OP the appointment of nn analyst for the Borough, and if so, the Board wished to be informed of the result.It was stated that the Local Government Board had been pressing this matter on the Council for nearly two years. Mr. Sale said he presumed the Council would send back the stereotyped reply-that they had not appointed an analyst yet. This was agreed to by the Council, and Dr. Pentland remarked that if it should be necessary to have an analysis made under the provisions of the Sale of Food Act, such analysis would be easily procurable from the Public Analyst of Worcestershire or other adjoining counties,

ISSN:0003-2654    

DOI:10.1039/AN8790400133

出版商:RSC    

年代:1879

数据来源: RSC

摘要:

134 THE ANALYST. REVIEWS. A Jfanunl of Organic Clienzisty, Practical ant1 Tlieoretical, for Colleges and Schools. By HUGH CLEMENTS. London: Blackie & Son, 1879. THIS work, despite its somewhat ambitious title, is a, small volume of some 280 pages. A large portion of it is stated to be a reprint from serial papers vhich have appeared in the IGzglish MtcJianic and TVorZtl qf Scieitce, and it is put forward with the object of forming a, ‘‘ test book ” for caildidates preparing for examination.There is one chapter on the (‘ Identification of Organic Substances,” whicli, in its general design and style, is original, and likely to prove useful to a student. This chapter extends to some 46 pages, and the author has evidently taken some pains to make it worthy of reference ; and, notwithstanding some curions and unfortunate errors which occur, he has, on the whole, sncceedecl.A more systematic arrangement mould, however, have improved it. The chapter on ‘( Oils ” would be useful for reference, if the errors, which are scattered through it, were weeded from it. Thus, we are told that linseed contains 20 per cent. of fat, and a few pages further the maximum limit is fixed at 27 per cent.But, having noticed these two chapters, we cannot give a single word of praise to the remainder of the book. Its evident object is to serve as a ‘‘ crib,” and enable a student to snccessfully pass an examination without having really acqnired the lrnowledge which the examinntion was ineniit to test. Nearly 90 pages are occupied with what professes to be a reprint of the papers set in Organic Chemistry at the Science a i d Art May Examinations for the last eleven years, with the correct answers or references to that part of the volume in wliich they may be found.It is obvious that the use of such a ‘ I key ” ns this must be attended with both chemical and moral injury to the student, and must compel the examiners to take far greater heed of the results of practical work than of the replies to questions wliioh may be learned by rote.Another chapter consists of a series of so-called exercises, which are simply a series of quest’ions, some being of the most puerile kind, snch as ‘‘ What organic substances taste acid ? ” sweet ? ” ‘( bitter ? ” “ peculiar ? ” while in others the student is yequested to make a qualitative analysis of the following “ mixtiiws,” among which appear beef, mutton, blood, oranges, urine, coal gas, ink, &c.We fear that Mr. Clements’ loose mode of expression is not calculated to foster habits of nccurncy in those who take his book as a guide. An I ~ i t r o i h c t i o n to Plbarntaceiitical and Jfetlical Cliemistyy (Tliroretical rtnd Descriptive ).By DR. JOHN MUTER, F.C.S. Air I)ttrodztction to Ajtalytica7 CJLemistry (:for Phaiwzaceutical and Meilical Students ). By the same author. Loiidon : Simpkin & &farshall, and BailliAre, Tinddl & Cox. These two volumes constitute the second edition of the author’s Phamacoiitical Clientistry, which has been thus divided, owing to its bnlky proportions, into a book for the laboratory and one for home study. The organic portion has been somewhatTHE ANALYST.135 extended, but otherwise the whole work retains its original scheme of teaching the salts under their respective acidulous radicals instead of following the usual metallic arrange- ment. Tlie practical volume contains iiiter nZiu a new course for the third group in the presence of phosphoric acid.Criticism at our hands is manifestly impossible. Xkeleton Xotes o n Annlyticnl Cheiizistry. London : Churchill, 1870. THESE skeletou notes are extracted from the fifth edition of Dr, Bernay’s 2C’otes for Stzdeuts in Clt.e)nistiy. They form a small and handy volume of about 50 pages. The author has not adopted the tabular form, but presents all the information in ordinary letterpress.The arrangement of the book is good, and by the careful use of four different types reference is very greatly facilitated. It is specially designed for tlie use of medical students, but those who are carryiiig the study of chemistry far beyond the simple requirements of the College of Surgeons, will find it not only a useful pocket companion but reliable for its accuracy.By A. J. BERNAYS. Nitric Xitrogen in Guano. MR. R. R. TATLOCK lias communicated a paper on the above subject to the Newcastle Chemical Society. He points out that by the soda lime process a large portion of tlie nitrogen, which exists in guanos in the form of nitrates, is transformed into ammonia during the combustion, and a considerable error therefore introduced into the analysis.As many natura.1 gumos contain 1 to 2 per cent, of nitrates the error is important even in reference to them, but becomes much more so when guano has been adulterated with nitrate of soda ; since, if a separate determination of the nitrates is made, and no allowance made for the quantity obtained as ammonia, a purchaser would virtually be called upon to pay for the nitric nitrogen twice over.The author has made a number of experimental soda lime combustions, in which amall known quantities of nitrate of liotash were intimately mixed with known organic substances such as starch, albumen, sugar, &c., and then burnt. Prom these experiments he draws the following conclusions :- 1. That using 3 of organic matter (starch) to 1 of nitrate, 45.30 per cent. of the nitric nitrogen caii be obtained. 2. That in no case was the whole of the nitric nitrogen converted into ammonia, the greatest proportion being 97-40 per cent. 3. That the results are somewhat variable, even with the same proportion of tlie ingredients, something always depending on the completeness with which the mixture is made, The author reviews the different methods used for determining Nitric Nitrogen in Guanos, and expresses a strong opinion in favour of Crums’ process, since the results are not affected by the organic matter. He points out, however, the desirability of testing the liberated gas by a warm solution of iron sulphate to prove that it is entirely nitric oxide.

ISSN:0003-2654    

DOI:10.1039/AN8790400134

出版商:RSC    

年代:1879

数据来源: RSC

摘要:

196 THE ANALYST, ANALYSTS’ REPORTS. Mr. C. Estcourt, Public Analyst for Manchester, in his quarterly report presented to the Council, stdcd t.li.at during Ihe quarter ending March 31st tlicre had been nnalysed twelve sample8 of milk, ninc of bread, seven of claret, six of port wine, two of tea, and one of sugar. The total number of samples aiialysed mas thirty-seven, and oue only was found to be adulterated, vix., a saiiiple of bread, which was found to contain seventeen grains of alum to the 4-lb.loaf. The analyst added that it was very gratifying to obseive that a great improvement had taken place in the quality of the milk supply. The report was adopted. Mr. W. W. Stoddart, Public Analyst for Bristol, in his quarterly report to the Town Council, statedTHE ANALYST. 137 that during the past quarter he had received eighty-three samples-fifty-nine from the inspector, and twenty-four from the public.Six samples of butter mere good, and six samples each of flour and lard were genuine. Mr. A. J. Edger, Analyst for the County of Durham, during the quarter ending March, examined 144 samples of food, drink, and drugs, and found 60 adulterated. The latter included 15 samples of milk, 20 of sweet spirits of nitre, 2 of tincture of rhubarb, 13 of cream of tartar, 3 of mustard, and 7 of whisky. Of the wine samples submitted for analysis all were unadulterated.

ISSN:0003-2654    

DOI:10.1039/AN879040136b

出版商:RSC    

年代:1879

数据来源: RSC

摘要:

THE ANALYST. 137 LAW REPORTS. ADULTERATED CEEAM OF TaRTaR.-six tradesmen of West Hartlepool were recently brought before a full bench of magistrates for selling adulterated cream of tartar. The superintendent of police had obtained a certificate from the County Aiialyst in each case, and these certificates gave the following results :-Tillim.n M‘Cabe, Lynn Street-tartrate of lime, 8.29 ; sulphate of baryta, 0.50 ; sand, 1.20 ; total, 9.99.Wm, S. Rutter, Lynn Street- tartrate of lime, 7.75. Francis Smith, Durham Street-tartrate of lime, 6.61 ; sand, 0.25. Robert Embleton, Stockton Street-tartrate of lime, 6.81. Thomas Layburn, Belle Vue-tartrate of lime, 7-75. M‘Cabe’s case was taken as a test case ; and in his certificate thc Analyst observed that “ commercial cream of tartar generally contains a small quantity of tartrate of lime ; ” and in M‘Cabe’s samplc it was ‘‘ present in excess.” Mr.Simpson, who appeared as the advocate of all the parties, submitted that the circumstances did not call for a conviction. The article was of the kind demanded by the purchaser, and it was impossible to keep it free from tartrate of lime. The Chairman, after some deliberation, said thc article might be considered commercially pure ; and as these were the first cases of the kiixl before them the bench W C ~ C not disposed to convict.They, hovcver, recommended tradesmen, for their own protection, to take a guarantee from the mliolesale merchant. Nor must the present decision be cited some weeks hence as a precedent. ADULTERATED LUNCH Bms.-At the Salford Police-court, James Bradshawe, confectioner, 412, Regent Road, appeared in answer to the summons charging him with having sold buns which were not of the nature, substance, and quality demanded, Mr.Walker, assistant to the Town Clerk, prosecuted. Mr. Thompstone, the inspector under the Act, said that on the 18th April he visited the defendant’s shop in Regent Road, and asked for seven lunch buns.He explained that he purchased them for the purpose of their being nnnlysed, and divided each bun into three parts. The analyst received the samples from witness the same clay, and being informed that they were adulterated, witness called at the defendant’s shop on the 30th April, and told him that the buns had been found impure. The defendant said that the buns were supplied by Mr.Casson, of Swan Street, Manchester. Mr. J. Carter Bell, the Public Analyst for the Borough, said he received the silmples of buns in question from the last witness. He analysed them, and found them to contain alum to the amount of fifty grains in the 41b. loaf. It was a very largc quantity, and that was the amount he declared it to contain after making full rcductions.The weight of each bun was about two ounces. Witness considered the buns very indigestible. The defendant now said that he purchased the goods from Mr. Casson, and broughl them to his shop ; that was all he knew about them. Mr. Makinson : Coulcl you detect alum in by the taste of the buns? Mr. Beil : No, the alum undergoes a change when mixed with the dough.Mr. Makinsoil, addressing the defenc!a!it, snid the Act, as no doubt the defendant was amare, made the seller of the adulterated article liable himself ; but he thought the character of the evidence was very different when the selling was by the person who made the bread. I t was, however, the duty of the seller to see that he got articles of a good quality, and he could not be altogether excused.The defendant was fined 10s. and costs. The defendant remarked that Rlr. Casson was considered a first-class tradesman, and it was with a desire to provide a first-class article that he had obtained the buns there. ADULTERATED MILIc.-Henry Blowers, local agent of tho Cleveland Dairy, wits charged on remand with selling adulterated milk. Mr. Fenwick, defended.Mr. F. W. Holt, sanitary inspector for the borough, had bought a pint of milk from defendant, and the County Analpt certified that the milk contained 54 per cent of added water. Rh. A. J. M. Edger, the County Analyst, now attended court, and gave evidence as to the correctness of his certificate. There was usually 86 or 87 per cent. of water naturally in milk. The Society of Public Analysts had determined that pure milk should not have less than 9 per cent of solids not fat, there never having been known to have becn less than that quantity in average milk.In the milk in question, only 8.78 per cent of solids not fat vas found, which could ]lot have been reduced except by the addition of water, Tliere might possibly be 10 per cent. of added water John Livingston, Church Street-tartrate of lime, 8 4 .The whole of the cases mere accordingly dismissed.138 THE ANALYST. in the sample produced, as his standard was low. Milk varied very little thropgliout the year. Mr. Fenwick declined to cross-examine the witness. A letter wa8 put in by Mr. Pattinson, analyst, which stated that, according to thc standard, there was amaddition of 7 per cent.of water, but that he had examined pure milk, and found it poorer. The Bench declined to admit it, as Mr. Pattinson was not present to support it. ADULTERATED BuTTER.-At the Derby Police Court, Mr. T . H. Bennett was charged with selling, to the prejudice of the purchaser, a pound of butter not of the nature, substance, and quality demanded. Rlr. A. Clarke prosecuted.He said on March 16th he went to the defendant’s branch shop, Stanley Terrace, Peartree Road, and asked for a pound of Is. butter, with which hewas served by the defendant’s assistant. When he told the assistant who he was, and why he had purchased it, the latter said, 6‘ I t is not butter, it is butterine.” He did not say so till he had been told who witness was. Witness divided the butter into three parts, and sent one to the Public Analyst, gave another to the assistant, and kept the other himself.On April 26th, he received a certificate from the Public Analyst, who said that the aample consisted of two-thirds foreign fat incorporated with one-third of butter, with water 14.5 per cent., and resembled the substance known as bntterine. Though animal and vegetable fats, other than butter fat, have 8 certain nutritive value, they haye not the nature and quality of butter as an article of diet.Defendant said that the article was sold as butterine, and not as butter. The Bench imposed a fine of 20s. and costs, in all $2 8s. 6d. ALUN IN BnEAD.-At the Salford Borough Police-court, John Brtxter, baker, was summoneci for selling adulterated bread.Mr. Walker, assistant to the Town Clerk, prosecuted. Mr. Thonipstone, inspector, stated that on the 6th May he visited the defendant’s shop and saw the defendant’s wife, whom he asked for a 4-lb. loaf. The bread was supplied to him, and he divided it into three parts in the usual way, at the same time telling her that he had bought the loaf for the purpose of being analysed.On the 9th inst. he again visited the shop, and purchased a sample of the flour from which the defendant said the bread had been made. He also submitted a sample of this to the analyst. Mr. J. C. Bell, Public Analyst for the Borough, said that on the Gth inst. he received a sample of bread from the last witness, which had been purchased at the defendant’s shop. He analysed it, and found it to contain 40 grains of alum to the 4-lb. loaf. The Magistrate, RIr. Makinson, was quite satisfied that this was a very serious case of adulteration, and he was also satisfied that the adulteration had been introduced by the defendant himself. It mas a very bad case. The defendant said he hoped the magistrate would be lenient, as he was a very poor man ancl had an aged mother to support, being also himself in delicate health. Mr. Makinson said that miglit perhaps induce him to be a little more lenient than he otherwise should have been ; but it was a very bad case, and he should fine him $4 and costs. The Bench ordered defendant to be fined 5s. and costs. The flour he found to be pure.

ISSN:0003-2654    

DOI:10.1039/AN8790400137

出版商:RSC    

年代:1879

数据来源: RSC