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THE A N A L Y S T . FEBRUARY, 1896. PROCEEDINGS OF THE SOCIETY OF PUBLIC ANALYSTS. AN extraordinary meeting was held on Wednesday, January 8,1896, in the Chemical Society’s Rooms, Burlington House, the President (Dr. Stevenson) occupying the chair. The following resolution was proposed by the Chairman, and seconded by IMr. Adams : ‘‘ That whereas the bye-laws of the Society state that * The affairs of the Society shall be managed by a Council, consisting of the President, Vice-Presidents, the Treasurer, and two Honorary Secretaries, and not more than twelve other members, five to constitute a quorum,’ it be added to these words that ‘ The Council, however, shall have power to elect as an additional member of Council the editor of the Society’s journal for the time being.’ ” After some discussion, the resolution was unanimously carried.The annual general meeting was then held, the President occupying the chair. The minutes of the previous meeting were read and confirmed. Mr. E. Russell Budden and Mr. H. Droop Richmond were appointed to act as scrutineers of the ballot-papers for the election of officers and Council for the ensuing year, and of the candidates proposed at the previous meeting for election to the Society. The Treasurer (Mr. E. W. J’oelcker) presented his report and accounts for the past year, which, on the motion of the Chairman, were unaniiiiously adopted. The PRESIDENT then delivered the following address : PRESIDEiNT’S -INN GAL ADDRESS. To-day the Society of Public Analysts attains its majority, for, although it is soiiie- what more than twenty-one years since the formation of such a society was mooted- by Messrs.Heisch and Wigner--it was not till December I, 1874, that it was con- stituted. Since then we have passed through the successive stages of precarious, though strong and lusty, infancy. Vigorous childhood succeeded, with growth, and, I may add, exuberant boisterousness. Indeed, in 1877, owing to some unfortunate misunderstanding or difference of opinion connected with certain matters in the administration of the affairs of the Society, several members, including the first President, Dr. Redwood, and the first treasurer, myself, retired from the Society. I t is pleasant, however, to record that Dr. Redwood, myself, and several other members, who at the time referred to felt compelled to retire from the Society, afterwards rejoined it, and took cordial part in its work.Again, we have passed through theTHE ANALYST. sedater years of youth, ever learning and feeding upon the rich stores of knowledge already provided for us. And POW that the Society has arrived at full manhood, it has the promise of a long, a successful, a useful, and, I may add, an illustrious future before it. Never, however, may it be our fate to grow decrepit and useless; and should the Society ever pass away, may it only be when its work is completely and perfectly done, and when our existence shall be merged in that of some other vigorous body ready and willing to carry on the work which we now do. A few years ago, as some of us know, hopes were entertained by some that the Society would make an honourable alliance with another Society, but the project was happily never seriously entertained by us, and our usefulness has not been impaired by our being merged in another body.Indeed, it is a matter for congratulation, and one in which we may justly take pride, that the Society has, on the whole, made steady, though not always equable, progress since the commencement of its career, and that it may now be regarded as a body of assured position, of power in public affairs, and of inestimable value and service, not only to public analysts, but to others, more especially the young and budding members of the chemical profession, SUP- plying a need which no other society administers to. Nor do we trench upon the prerogatives of the three kindred societies--the Chemical Society, the Institute of Chemistry, and the Society of Chemical Industry.When we look back to the earlier days of our Society, and to its first proceedings, recorded in a now scarce little volume, we see, not how modest were the aims-for they were never modest-but how small was the performance when compared with the present doings of the Society. But, although limited in amount, the earlier work of our Society was of excellent quality, and the restless energy of the first President, and the still ttiore restless activity of the first Secretary, Mr. Wigner, must ever demand our deepest gratitude. Never- theless, we did our best, so far as our pecuniary resources permitted. I t may be interesting for me to sketch briefly the early history of the Society, and this, as one of the founders of the Society, I am able to do, but I have to express my great indebtedness to our Secretary, Dr.Dyer, for invaluable aid. As I have already said, Messrs. Heisch and Wigner were the chief originators of the Society of Public Analysts. A preliminary conference of Public Analysts appointed under the Act of 1872 was held at the Cannon Street Hotel on July 28, 1874. This had of course been preceded by several private meetings. On August 7 a second con- ference was held. Various committee meetings followed, and eventually the Society was duly constituted, and held its first ordinary meeting on December 1, 1874. The first officers and council were : President, Dr. Redwood ; Vice-presidents, Dr.Hassall and Mr. Wanklyn ; Treasurer, Dr. Stevenson ; Secretaries, Messrs. Heisch and Wigner ; other members of Council, Messrs. Allen, Estcourt, Sutton, Bernays, Rogers rand Tripe. I t is gratifying to know that, after the lapse of twenty-one years, of the twelve first members of the Council six survive-just one half. The original members of the Society numbered sixty-three. Even at this early period of its existence a committee proceeded to draw up definitlions of adulteration, and standards and limits for whole and skinillied milk, butter, coifee, tea and vinegar. Thus early did the Society go to the root of matters which even now greatly concern us. The Society But our means, as I well know, were small.THE ANALYST. 31 also got quickly to work in other directions, and on February 5, 1875, papers were read on ‘‘ The Detection of Alum in Bread,” by Mr.Wrtnklyn, L L On the Analysis of Milk,” by Dr. Redwood, ‘‘ On the Natural Constituents of Wine,” by Dr. Duprh, and ‘‘ On the Decomposition of Milk,” by myself-a subject still to the fore. An arrangement was made with the proprietor of the C‘hcmicnl News, by which our proceedings appeared in that journal, and thus the Society and its doings were brought prominently before the scientific public. Subsequently our proceedings appeared in the L 4 x ~ ~ ~ s ~ , which was started by Dr. Mnter in 1876, and until that journal was fully established our doings did not come before so wide a public as before, but the increase in the circulation of the ANALYST and its wider distribution, followed by the acquisition of that journal by the Society itself as its own organ, have been of inestimable benefit to us and to public analysts generally.With the new year our own organ appears in an improved form-larger and better, as we think, with more abstracts from a wider range of journals, so that the ANALYST is now in- comparably the best journal of analytical chemistry published in this country--a, journal of great value as recorder of advances in analytical chemistry, an excellent work of reference, and a valuable property as an asset of the Society. I think I do no more than what it is right for me to do when I express my own grateful thanks to the editor, Dr. Sykes, who makes his editorial work truly a matter of love and pleasure.I trust that our new departure, and our aim to produce a larger, better, and more useful ANALYST will prove a large success. We of the Editorial Committee hope that by inserting more abstracts from foreign journals with a wide range of foreign scientific literature, and by the more rigid exclusion from its pages of what is obviously old, or trivial, or valueless, t o produce in the course of a few years a journal second to none either here or abroad as an exponent of advances in the field of analysis and technical research. The year 1875 is inemorable as the year in which the tentative Statute of 1872 was nearly entirely repealed, and the passing of the existing -4ct of 1875, from which the term ‘‘ adulteration ” disappears. With the passing of the new Statute the Society was greatly concerned.The Council was busily occupied with the considera- tion of the draft Bill before Parliament, and with endeavours to bring about the passing of that Bill in as satisfactory a form as possible. Official interviews with Government representatives, and non-official interviews with nienibers of the Legis- lature, followed the deliberations of committees and Council, and no doubt resulted in the presence of fewer bleinishes than might otherwise have existed in an Act which, though it has many defects, has proved, on the whole, excellent in working. The hard work of Lord (then Dr.) Playfair, M.P., and Sir Charles Cameron, M.P., in re- presenting in the House of Coriiinons the views of the public analysts of that day was acknowledged by their election as honorary members of the Society.The Society has, as I have already said, made steady progress since its founda- tion, and the energy, good sense and determination of its officers and members have been abundantly proved in the past. The dissensions which unhappily arose during the earlier years of our existence were but a passing cloud. We all learn-or all who are capable of learning soon find out-that if a society is to be maintained in prosperity, honour, and public estimation, this must be done, not by glib tongues,32 T4E ANALYST. sharp repartee, and facility in debate, but by steady work, a kindly consideration for views and opinions which we do not altogether share, temperance in criticising others, and a keen criticiam of ourselves.Throughout the existence of the Society it has had a constant inflow of papers, nearly six hundred having been read and discussed during the twenty-one years of its working-not to speak of other papers, not read, but published in the API’ALYST. The papers read before the Society during the past year are as follows : “ Note on the Cse of Maize as an Adulterant of Oatmeal.” “ Note on a Sample of supposed Lard.” I ‘ Note on a Sample of Lardine.” By R. Bodmer. “ On the Determination of the Bromine Absorption of Fats Gravimetrically.” “ On the Coiiiposition of Milk and Milk Products.” ‘‘ On the Relation between Specific Gravity, Fat, and Solids-not-fat in Milk.” “ On the Maumenk Test.” By H. Droop Richmond. “ Notes 011 Cinnamon.” By Bernard Dyer, D.Sc., and .J. F. H.Gilbard. I ‘ On the Examination of Potable Water, Chemical and Biological.” By A. Duprd, Ph.D., F.R.S. “ The Interpretation of the Results of the Chemical and Biological Examination of Potable Water.” By J. C. Thresh, M.B., D.Sc. I ‘ The Composition of some English Cheeses.” By W. Chattaway, T. H. Pear- main, and C. G. Moor, M.A. ‘‘ The Testing of Oils by the Oleorefractoineter.” I ‘ The Determination and Identification of the Carbohydrates in Milk.” “ On Formalin as a Milk Preservative.’’ By S. Rideal, D.Sc. ‘‘ A Comparison of the Organic Carbon and Nitrogen results obtained bj- Dr. Frankland and the Companies’ Analysts from the Waters supplied by the Metropolitan Water Companies. By E. J. Bevan. By Otto Hehner and C. A. Ily By John Khite. By B. Kitto. By Otto Hehner.By H. Droop Richmond. By H. Droop Richmond. By T. H. Pearmain. By A. Wynter Blyth, M.R.C.S. By W. C. Young.” ‘‘ On the Use of Formalin as a Preservative of Milk Samples.” ‘‘ Note on Formalin.” “On the Heat evolved on Brominating Oils.” By H. Droop Richmond and L. Ii. Boseley. Mitchell, 13.A. John Hughes. Feeding Experiments with Indian Peas containing Latli~y.zts Scctiz~zis.” Pseudo-Woollen Fabrics.” By E. G. Clayton. “ Note on Artificial Coffee.” By T. 11. Pearmain and C. G. Moor, M A . l L Note on Adulterated Sandal Wood Oil.” By T. H. Pearmain and C. G. Duclaux’s Method of Estimating Volatile Acids, and the Laws of Volatility.” ‘ 4 On the Presence and Proportion of Free Fatty Acid in Oil-cakes and other Moor, M.A. By H. Droop Richmond. Feeding-StufYs.” By Bernard Dyer, D.Sc. and J.F. H. Gilbard.THE ANALYST. 33 Note on the Bromine and Iodine Absorptions of Linseed Oil.” By Rowland Note on a Becent Milk Case involving an Example of Abnormal Milk.” By R. Note on Filled Cheese.’ ” By R. Bodmer. Williams. Bodmer. ‘(The Composition of Condensed Milk.” B)- T. H. Pearmain and C. G. By Alfred H. Allen. By E. By Moor, M.A. Note on the Composition of Cominercial Condensed Milk.” I ‘ Note on the Estimation of Xinute Quantities of Metals in Liquids.” ( ( Note on a convenient forin of Polarimeter for examining Essential Oils.” Russell Buddeii elid H. Hardy. E. Russell Budden. The Microscopical Examination of Water.,’ By W. J. Dibdin. Some of these communications are of a high order of nierit, and the discussioll which followed the papers of Drs. DuprC! and Thresh on water examination were most interesting and valuable.The claims of chemical analysis, which had been too much aspersed by bacteriologists, were ably vindicated ; whilst the value of bacteri- ology was duly acknowledged. -1 paper by Mr. Dibdin, on the microscopy of waters, formed a fitting addendum to those previous communications I have referred to. Since the discussion of last spring, bacteriology, in the hands of Dr. Klein and others, has made distinct advances in the solution of disease-problems connected with water-supply, and in the not distant future we may expect that chemical analysis and bacteriology will go halid in hand in the solution of questions arising as to the relations of water-supply to outbreaks of disease.So far back as 1880 the Society took in hand the question of water-analysis, thocgh, singularly enough, it is a question which little concerns us qua public analysts; and a Committee was appointed to consider the best methods of per- forming, and reporting on, water-analyses. I n 1881 the report of the Committee was published in the ANALYST. The instructions and suggestions laid down in this report were most valuable, and have been adopted generally, not only by public analysts, but by a large proportioii of those chemists who undertake these analyses. Throughout the whole of our career the subject of milk-analysis, and standards and limits for milk, have been prominently before us; and it is to be regretted that no final settleiiient of limits has been arrived at, and conflicts between chemists and the Government cheiiiists arise still.So far back as 1883 a committee wits appointed by the Society to consider and determine the best method of milk-analysis The committee continued its labours for nearly two years. Their report to the Society was published in 1885, and recommended the -\dams process for the determination of butter-fat. It marks one of the most important points in the history of the Society, as, up to that time, each individual analyst worked by his own particular modification of some one or other’s modification of milk-analysis ; and as nearly all the methods in use were imperfect as regards the extraction of fat, the results of different analyses were hardly comparable in terms of one another.It was hoped that the differences between the views of public analysts and the34 THE ANALYST. Government chemists were about to become minimized a year or two ago, and the pronouncement of 3Ir. Bannister before the Food Products Adulteration Committee that the limits of the Government chemists were at that tinie H . 3 per cent. for solids- not-fat, and 2-75 per cent. for fat, encouraged public analysts, since they believed that these limits would be adhered to. Our expectations have, however, not been fulfilled. Some of us, who have certified milks containing less than 3-75 per cent. fat as deficient in this constituent, have found that the Government chemists, though also finding less than 2.75 per cent. fat, have pronounced the milks to yield no evidence of deficiency.The old cry again arises that it is impossible to predict what amount of change will take place on keeping in a, non-sterilized coiiimercial milk ; and still less to ascertain, with even approximate accuracy, the amount of solids-not-fat originally present in a inilk which is much decomposed at the time of analysis. Every pretension to the contrary should be keenly scrutinized ; and until those who make the pretension submit their methods of procedure and calculation to public criticism, they cannot expect their conclusions to be accepted as valid. Mr. Bannister has publicly stated that the new and analytical method of arriving a t original solids- not-fat yields figures substantially the same as the old Somerset House time-allowance, which public analysts do not accept, and for sufficient reasons.Ere long, before a reappointed Food Products Adulteration Committee, I hope the subject will be thrashed out. I am confident that eventually our contentions, based upon sincere and deep conviction, will be accepted. Our earnest endeavour in the near future must be to secure limits below which articles of food, drink, and drugs inust not be allowed to fall-limits fixed by some competent and authoritative body, on which public analysts must, of course, be adequately represented. I amin not insensible to the fact that limits are but imperfect instruments; but I feel assured that they present less evils than an absence of authoritative standards, and the manner in which they have worked, e.g., in the British Pharmacopcria, is highly encouraging.We must press for the establishment of standards and limits for the composition of all definite and well-recognised articles of food, drink, and drugs. Evidence as to what these standards and limits should be is daily accumulating, and our members are not slow in producing the evidence on which they should be based. The joint deliberations of public analysts and commercial men of high standing, equally interested with ourselves in securing for the public articles of fair quality, ought to suffice for the securing of just, equitable, and sufficient standards and limits. During the forthcoming year much useful work lies before the Society, not only in the improvement of methods of analysis, but also in work of a public nature. There is little doubt that the Food Products Adulteration Committee will be re- appointed with such alterations as are necessitated by political changes, and, if so, we shall claiin, and I hope obtain, a hearing.The iiiost useful services that Mr. Hehner has rendered to public analysts by his care and vigilance in attending the meetings of the Committee, and watching over the interests of public analysts, deserve a generous recognition. We all tender him our cordial thanks for his past services in this respect, and hope and anticipate that he will continue them until our ends are achieved. Watchfulness, preparedness, patience, courage are required ; and these we know will not be wanting till and when the time arrives for action.THE ANALYST. 35 During the past year we have lost three of our members by death: Dr.W. Morgan, Nr. Crook, and Dr. Cresson of Philadelphia. An appreciative uotice of Dr. Morgan has already appeared in the ANALYST. To all who knew him he appeared to be a man of great natural ability and energy, who raised himself by his unaided efforts to a conspicuous position in South Wales, and against odds which would have weighed many a man to the earth. He to the last bravely and nobly fought the battle of life with a smiling face. The number of Honorary Meiiibers, 10, and of Ordinary Members, 210, is exactly the same as at the close of 1894, whilst the number of -Associates has fallen from 31 to 26. Mr. ALLEN, in proposing a hearty vote of thanks to the President, said he was sure that everyone present had listened to the address with very great interest.The Society was to be congratulated on having had put before it so many interesting facts, which, although probablynew to inany members, brought back a flood of recol- lections to his own mind. He would like to express his sense of the loss which had been sustained in the death of Dr. Morgan, who had been a personal friend of his own, and a chemist for whom he had the greatest respect. -\s the President had said, Dr. Morgan had struggled under domestic troubles of a most heart-breeking character, but his industry, perseverance, and genius had made themselves apparent to everyone who came in contact with him. The President had also referred to the late Dr. Cresson, of Philadelphia. He (Mr. Allen) was probably the only member of the Society who was personally acquainted with Dr.Cresson, who was a man of great analytical experience, and had a very large practice, holding, among other appoint- ments, that of chemist to the Pennsylvania Railway Company. He (Xr. Allen) once visited Dr. Cresson at his laboratory, and found him to be an exceedingly genial man, and one who took ti very great interest in the work of public analysts in England. MR. HEHNEH., in seconding Mr. Allen’s proposal, expressed the pleasure with which he had listened to the President’s address, and hoped that. the younger members of the Society would be induced thereby to study the earlier history oE the Society, from which useful lessons might be drawn. He asked the President’s consent to allow his address to be printed in the next number of the ANALYST.a, c clam at ion. His inenlory will be ever dear to his fellow-labourers. On the motion being put to the iiieeting by Mr. Allen, it was carried with The PRESIDENT (whose rising was received with loud applause) said he was very much obliged for the cordial vote that had been passed, and to his old friends, Messrs. Allen and Hehner, for the kind manner in which they had proposed it. It would give him the greatest pleasure to see his address appear in the journal. Before con- cluding, he had to propose a vote of thanks to the Chemical Society for the use of their rooms during the past year, which he hoped would be cordially passed. It gave dignityto the Society of Public Analysts to meet in those rooms, where so many distinguished societies met, and he felt that they ought to be very grateful for the Chemical Society’s kindness. The vote of thanks was passed with acclamation.36 THE ANALYST. The scrutiiieers reported that the list of Officers and Council elected for 1896 was P~-esidc~zt-T. Stevenson, M.D., F.R.C.P. Vice-Pwsideiits (who have filled the office of President)-M. A. Adams, F.R.C.S. ; A. H. Allen; Sir Chas. A. Cameron, M.D., F.R.C.S.; A. Duprb, Ph.D., F.R.S.; Otto Hehner ; Alfred Hill, KD., F.R.S.E. ; J. Muter, Ph.D., M.A., F.R.S.E. (Who have not filled the office of President)-A. Wynter Blyth, M.R.C.S. ; John Pattinson ; John A. Yoelcker, M.A., B.Sc., Ph.D. Treasu I'cT-E. W. Voelcker. Hoiz. Seci.etcti.ics-Edward J. Bevan, Bernard Dyer, D.Sc. Othw Menhbei-s of Cowd-Leonard Archbutt, Bertram Blount, E. Russell Budden, Charles E. Cassal, W. Chattaway, C. H. Cribb, B.Sc., W. J. Dibdin, W. W. Fisher, M.A., Sidney Harvey, B. Kitto, H. Droop Richmond, Alfred Smetham. Nr. A. C. Chapman, F.I.C., was elected a Member, and Messrs. Norman Leonard, B.Sc., F.I.C., and Harry M. Smith Associates. Mr. Stevenson J. C. G. Macadam, jun., F.I.C., of Edinburgh, was proposed for election as Member, and Mr. Charles Crocker, of Swansea (assistant to Messrs. Morgan, Sons, and Seyler), as Associate. A paper was read entitled : ' I Note on a Series of Analyses of a Private Water Supply," by E. Russell Budden. as follows :

ISSN:0003-2654    

DOI:10.1039/AN8962100029

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

36 THE ANALYST. THE ANNUAL DINNER OF THE SOCIETY. This took place the same evening at the Criterion, under the chairmanship of the President. Nearly seventy-five members and guests were present, amongst the latter being Mr. Hudson E. Kearleg, M.P., Mr. T. H. Elliott (Secretary of the Board of Agriculture), Dr. Thorne Thorne, C.B., F.R.S. (Medical Officer of the Local Govern- ment Board), Professor Thorpe, F.R.S., Mr. A. G. Vernon Harcourt, F.R.S. (President of the Chemical Society), Mr. M. Carteighe (President of the Pharmaceutical Society), Mr. T. H. Tyrer (President of the Society of Chemical Industry), Dr. James (Secretary of the British Institute of Public Health), and Mr. G. C. Barnes (Master of the Joiners’ Company). The toast of ‘( The Queen” having been duly honoured, Mr.HEHNER proposed “ The Houses of Parliament.” He said that all members of the Society of Public Analysts had been looking forward to the imminent reform of those Acts of Parliament under which they held office. He hoped that the attention of the Legislatxire might not be averted from that most necessary reform by the preseat coinplications in foreign politics. England was the first country to institute and set into operation Acts directed against food-adulteration. 0 ther countries had not only imitated England’s exainple, but had improved upon our Food and Drugs Acts. Circunistances had altered to such an extent in the twenty years during which these Acts had been in force, and so many defects had manifested themselves in carrying them out, that they iiiight now be considered altogether antiquated, and in urgent need of revision.He pointed out that while originally legislation against food adulteration was undertaken in consequence of the agitation of a few individuals,THE ANALYST. 37 at present the public, the trade in articles of food, and the officers under the Act were unanimous in asking for more stringent legislation. The good which these Acts had done was now freely acknowledged, but far greater benefit might yot be effected. A very important step had been taken by the last Parliament towards amending legisla- tion in this direction by the appointment of the Food Products Adulteration Committee. Although that committee, from circumstances over which it had no control, had undergone a very serious amount of decomposition, he hoped that a similar coiiimittee would very soon be reappointed and would conclude its labours.He coupled with the toast the name of a prominent member of the late Committee, who had devoted himself and given his great practical experience to that committee, Mr. Hudson E. Kearley, M.P. Mr. HUDSON E. KEARLEY, in responding, said that the condition of our foreign relations at the present time would probably render it necessary for Parliament, on its reassembling, to give close attention to external, rather than internal affairs ; but he sincerely hoped that the question of food and drugs legislation would not be lost sight of. He trusted that the committee would be reconstituted, and that an early opportunity would be afforded to the public analysts of laying before that body their views, which were the outcome of a long experience of the working of the present laws, as to the foriii that future legislation should assume in order to reach that degree of efYiciencJ- which, in the interests both of the public and of the analyst, was so much to be desired.Dr. J. A. I-OELCKEX, in proposing the toast of ‘‘ The Local Government Board and the Board of Agriculture,” said it was the desire of the Society that, public analysts throughout the country might be brought into closer connection with these two Boards, upon whom devolved the final selection of fit and proper men to fill the appointments of public analyst and district agricultural analyst. The duties attached to the making of these appointments were not only very important ones, but were often of an extremely delicate character, and he wished to take the opportunity of impressing upon the representatives of the Boards concerned the serious responsi- bility which rested upon them in this matter.It might at one time have been found handy to combine with the appointment of medical officer of health that of public analyst, as a matter of economy and local convenience, but at the present time the position of public analyst was one which could not be filled properly by a man who had received oiily a inere smattering of chemical training. It was a position which required special training, knowledge, and experience, not only in general chemistry, but in actual public analytical work. It was the duty of bodies like the Society of Public h a l y s t s to endeavour to promote the appointment of none but properly qualified men, and it was to those Government departments which had to investigate the qualifications of candidates that they looked for co-operation and support.They wished as public analysts to see less and less of what had been put forward as indi- cating continual disagreement between Government departments and public analysts. That there had not been perfect harmony in the past had not been invariably the fault of the Government departments, but had often been due to insufficiencies and incapacities upon the other side; but he ventured to think that the Society now combined in its ranks iiieii who were worthy representatives of analytical chemistry,38 THE SNALSST.and who could stand before the general public as fully qualified to undertake the duties of their position. He would like to refer to a singular anomaly which he thought ought to be removed. Those who were district agricultural analysts under the Fertilizers and Feeding Stuffs Act; were in the happy position that the chief agricultural analyst was also an official of the Board of Agriculture. From this it followed that if, as a district analyst, he (Dr. Voelcker) had perhaps a slight difference of opinion with the chief analyst on any particular point, their relative positions were such that they could both meet and talk over the matter with Mr. Elliott, and he had not the slightest doubt that, in Mr. Elliott’s comfortable room, they would speedily settle all their differences without being driven to air them in a court of law for public benefit.There was a distinct advantage in having both the analyst and the official referee in the same department. He ventured? however, to put forward, by way of contrast, what took place under the Food and Drugs Act. Supposing that he was a public analyst, and that, a prosecution having resulted upon his certificate, the remaining sample was submitted to the official referee. There was no comfortable room like that of Mr. Elliott’s in which possible difficulties might be settled; on the contrary? there was absolutely no official common ground upon which the public analyst and the official referee could meet, and the consequence was that the matter had to be brought into court, and an unseeinly wrangle ensued between those who wished to support the public analyst and those whose object was the reverse. This was not an edifying spectacle either for analysts or for the public, and it seemed to him that it would be a very good thing if it could be reinoved. They, as analysts, ought to be able to discuss with the officials points on which opinions might be at variance, and thus “agree with thine adversary’’ before going into court, and not, as at present, be compelled to bring such matters into public review, and before magistrates who knew little or nothing about the real points involved.On the part of public analysts generally there was a feeling that something like a committee should be formed, on which public analysts would be fully represented, and in this way they might discuss matters with the officials of the Inland Revenue and other departments concerned.In this way there might be some understanding come to as to what limits ” should be fixed, so that they might not go into court as a set of scientific inen who could not agree one with the other. The public thought more of the disngreenients between them than of the science which they professed to practise. The Board of Agriculture was much to be congratulated for the efforts which it had made towards suppressing the importation of foreign adulterated butter. He was sure that public analysts would find in Mr. Elliott a sympathetic officer, and one, moreover, who was willing to act on behalf of the public good. At the same time, it was satisfactory to note that under Dr.Thorpe’s rule a point had been reached when samples that really ought not to would no longer be allowed to do so, on the ground of their being up to the quality of some exceptional and abnormal sample that had at some time or other been discovered. As public analysts, they might now begin to feel satisfaction that the standards ” adopted by the Society of Public Analysts were being more and more nearly reached by the official referees and understood by the public.THE ANALYST. 39 Dr. THOBNK THOME, C.B., F.R.S., returned thanks as the representative of the Local Government Board, and assured the company that the aim at Whitehall was the same as tshe aim of the Society of Public Analysts, viz., to raise the standard and status of the public analyst in the estimation of the public and from the scientific point of view.He thought that some of the improvements alluded to by Dr. Voelcker were due to the Local Government Board. A public analyst should be, to quote Lord Macaulay, “ a nian of parts,” and they asked in a candidate for this position, first and foremost, that he should be an expert in chemistry ; second, that he should, from the nature of his avocations, be able to spend such time in his laboratory as to maintain his expertness; and next, that, since the question was one of Foods and Drugs, he should have certain qualifications in physiology, therapeutics, and micros- copy. It would be well, he thought, if all candidates were required to pass a definite examination, but Parliament had seen fit to decide otherwise, and had imposed upon the Local Government Board the task of deciding as to competency.For this purpose the Board were dependent on documentary evidence, which they always required; but if there was one point upon which they had difficulty in obtaining satisfactory documentary evidence, it was as to competence in cb.emistry. Now, what was the remedy ? When they received testimonials and certificates signed by men whose names would carry weight anywhere, they could not question their bond Jides, they could not do otherwise than accept these as proofs of competency ; and yet everyone knew what testimonials sometimes were. There was a gentleman he knew in another branch of life who always gave each applicant a testimonial in these terms : (‘ If Providence preserves his life, he will be an ornament to his profession ” (laughter).After he had done this for a few years, no one went to him for a testimonial (renewed laughter). I n the case of a candidate for the post of public analyst who was a qualified medical man, his proficiency in physiology, thera- peutics, and microscopy were amply guaranteed, and, therefore, he (Dr. Thorne) maintained that if a medical man was really an expert chemist, and had a district which would enable him to spend a large amount of time in his laboratory, he was likely to be the best public analyst ; but chemistry must necessarily be regarded as the most important qualification. As he had said, the main object of the Local Government Board was to raise the status of the public analyst, to ensure as far as they possibly could that every man appointed should be competent.They quite agreed with Dr. Yoelcker that the Medical Officer of Health ought not, in virtue of his office, to be public analyst. His honest opinion would be in this direction, that no Medical Officer of Health, however competent, should hold the post, if he had a district which, by reasoii,of its population and area, was such that he could not, without neglect of his medical officer’s duties, spend ample time in laboratory work. Under present circumstances, and in the absence of an examination (which possibly might be provided by the Institute of Chemistry), they were doing their very best. On the one hand, however, they had the candidates for appointments, and the local authorities-who resented the interference of the Board in the direction of demanding fuller proof of competency; and, on the other, the dificulty which the Society had often realized, of securing, as the result of mere documents, proof of r e d expert com- petency in chemistry.Under these circumstances, they could not please all men.40 THE ANALYST. He had been more free, perhaps, in expressing his opinion than was customary in an after-dinner speech, but he did not speak so much as an official as one whom the Society had kindly honoured as their guest. Mr. T. H. ELLIOTT, in responding for the Board of Agriculture, said that while Local Government was a prosperous institution, Agriculture was but a poor sister, who for the last fifteen years had been suffering from very severe depression.The Board of Agriculture were, therefore, especially grateful for the manner in which this toast had been proposed and responded to. The Society of Public Analysts had rendered valuable assistance to the Board in connection with the sale of fertilizers and feeding stuffs. The Act which regulated the sale of these articles was recent, and it was too soon to see definitely how it would work; but he thought there were signs that some assistance had been afforded to the farmer. The subject of the adulteration of fertilizers and feeding stuffs had formerly been the constant subject of discussion at agricultural meetings, but it was now but rarely mentioned. He attributed this absence of complaint to the existence of a thoroughly competent body of agricultural analysts, and he wished to express his gratitude, on behalf of the Board of Agriculture, for the able assistance which the Society had rendered in connection with the passing of the Act, and in bringing it into operation. It had been the most sincere desire of the Board that only men of the first rank should be selected to act as District Agricultural A4nalysts.No pains had been spared to impress upon local authorities the views of the Board as to the requisite qualifications, and the circular issued for that purpose had been framed in consultation with several gentlemen who were present before him. He would also wish to refer to the fact that a strong feeling existed that the agricultural industry would be much assisted by further measures to prevent adulteration. The work which the Board had recently undertaken in connection with the analysis of butter had led hiin to the conclusion that if the traders, great and small, of this country would make proper use of the science of analytical chemistry, the result would be that the evil of adulteration would practically cease to exist.It was probably necessary that further action should be taken by Parliament, but he would venture to hope that the traders and importers of this country would themselves assist by taking advantage to a greater extent of the services of analysts. Most of those present belonged to some one or other of these societies, and they had with them the President of the Chemical Society, with which he had himself been connected for over thirty years; and whatever differences in views might exist as to the relative merits of diflerent branches of chemical knowledge, he felt sure that they would all appreciate the services rendered to science by Mr.Vernon Harcourt and the Chemical Society. Mr. A. G. VERNON HAECOUI~T, in replying, said that the claiiiis of the learned societies to an expression of goodwill on such an occasion as the present were well understood. It was upon the researches of those who made it the whole or a part of their work to pursue knowledge for its own sake that the practical applications of science were based. The learned societies helped to maintain that internationa The PXESIDENT proposed the toast of The Learned Societies.”THE ANALYST.41 character which science, perhaps, even more than literature, possessed, aud which should have some friendly influence upon the solution of the grave political questions which had suddenly sprung up between us and our American and German friends. Mr. MICHAEL CARTEIGHE (President of the Pharmaceutical Society), in pro- posing ‘‘ The Society of Public Analysts,” said that at the time when the question of adulteration was first raised in this country, it was impossible to point to a single person who possessed the necessary qualifications of a Public Analyst. -Ilmost simultaneously with the passing of that Act which enacted that competent men should be appointed by competent authorities to stand between the public and the dishonest trader, the Society of Public Analysts was formed.The Society imme- diately set to work to technically educate its members up to the proper standard of efficiency, and they were to be congratulated upon the results achieved. They had encouraged every member of their body to devote his ability to some branch of research connected with public analysis, and had founded a journal whose numerous volumes contained a mass of information which was a credit to the country. They had lately been instrumental in getting Parliament to appoint a Select Committee to investigate the whole question of the sale of food and drugs, and for the assist- ance of that committee had drafted a Bill embodying the views which their long and detailed experience had suggested to them. He believed that the Society, if wisely directed (as it had been for many years), and loyally supported by its members, would continue to grow and prosper.Their present President, whose name he had t o couple with the toast, had been associated with the Society from its commence- ment, and it was interesting to note that he was their first Treasurer. He was the successor to a long line of distinguished Presidents, commencing with Dr. Redwood (who might be said to have been the first Public Analyst), and who was followed by Dr. Duprk, Dr. Muter, Mr. Heisch, Mr. Wigner, Dr. Alfred Hill (of Birmingham), M i . Allen (of Shefield), Dr. Adams (of Maidstone), Mr. Hehner, Sir Charles A. Cameron (of Dublin), and, lastly, Dr. Stevenson. Among all these men there was not one who had not made a name in science before he became a public analyst, and most of them had contributed a distinct quotum to the advance of technical work.Dr. Stevenson was a very distinguished man in many ways; his ability and sound judgment were held in great respect by those members of the Government service with whom his work brought him into contact, and he merited the confidence of all who were connected with the sale of articles of food and drugs. The PRESIDENT, in responding, said that public analysis had been a thing of growth. They were precipitated somewhat rashly upon the public, but he thought that they had justified their position, and that they had done as much as any other body to advance not only technical analysis, but scientific analysis also, besides obtaining a by no means unimportant voice in public affairs.Their journal un- doubtedly occupied the first position among those devoted to analytical chemistry in this country, and in its enlarged and improved form would compare favourably with those of foreign countries, Mr. CASSAL, in proposing t4e toast of 4 6 The Visitors,” coupled with the name of Professor Thorpe, said that it adorded a great deal of pleasure to the members of the42 THE ANALYST. Society to welcome so many distinguished guests upon that occasion. Their presence was a sufEcient guarantee of the high appreciation in which the Society’s work was now held by those who, from various points of view, inight properly be regarded as amongst the best qualified to judge of it. The presence of Dr. Thorpe was especially gratifying to the Society.As public analysts, they could not wish for a man possess- ing better qualifications to enter upon the direction of the enormously important Government Department of which Dr. Thorpe was now the head. He believed that he spoke with the full approval of his colleagues when he said that Dr. Thorpe would assuredly command the respect and confidence of the public analysts of Great Britain in the difficult and delicate post which he had accepted. There had, of course, been various difTerences of opinion in the past between public analysts and the chemists of Somerset House, but those differences, he fully hoped, belonged to the past. Should any even serious differences or disagreements as to the analytical data and the value of analytical processes occur in the future, he believed they would be easy of adjustment, for he was convinced that they could be settled by amicable and full and free discussion in the true scientific spirit.H e trusted and believed that in the future, far from there being differences of opinion and divergence of action between public analysts and the Somerset House Analytical Department, there would be united action directed to a corninon end-a condition of things which could not fail tG accelerate the coming of the time when the profession of analytical chemistry would, by common consent, be held to have deserved well of the people, and would accordingly receive its just meed of recognition and respect from the nation. Professor THORPE said that the duty which had been placed upon hiin was, perhaps, the most pleasurable that could be undertaken by any speaker that evening.A succession of very able speeches had been delivered by gentlemen representing the various interests and associations with which the Society was connected, but he thought that previous speakers might well envy him his present task, for of all the duties that might be imposed upon an after-dinner speaker, undoubtedly the most easy, the most pleasant, and the most grateful was that of tendering thanks to one’s hosts. He and his fellow visitors who had been the recipients of the kind hospitality of the Society would leave that room with a pleasant recollection of a pleasurable evening. As regards himself, he wished to thank Mr. Cassal for the kindly terms and gracious manner in which he had referred to him in connection with the position which it was his lot now to fill.Those present would not misunderstand hini when he said that he had entered that room, he would not say in trepidation, but with a feeling of slight uncertainty as to what was going to befall him, The warmth of his reception had, however, dispelled at once even the slightest shadow of a shade of any doubt he might have entertained on that head, and he could only thank them sincerely for the kindness, courtesy, and hospitality with which he had been greeted. When he was requested to speak that evening, the saying at once occurred to him that there coiiies to every man golden opportunities for holding his tongue. But, however officially reticent he might have desired to be, his tongue was loosened by the kind expressions which had fallen from Mr.Cassal. He was sure it was the desire of the Society that the great body of public analysts might be able to work inTHE ANALYST. 43 harmony with the laboratory which he had the honour to direct, and which, by an act not of their own seeking, was made, in a measure, a court of reference and appeal If that was their sentiment, he sympathized with it from the bottom of his heart; and he had no stronger desire, in dealing with the many duties of his office, than that both he and they, public servants as they were, should work together cordially and harmoniously in the discharge of their public duties. Their end was the same- the welfare of the community-and that end could be most quickly and most certainly assured by friendly and harmonious co-operation.Dr. Voelcker, in the course of his admirable speech, had referred in feeling terms to the unhappy fact that he (Dr. Thorpe) had not a pleasant rooin in which the questions which might arise from time to time between the Government Laboratory and the public analysts might be discussed in the same agreeable manner as at the Board of Agriculture, and amidst the same pleasant surroundings as it was the good fortune of his friend. the Secretary of the Board, to possess. None regretted that circumstance more lreenly than himself. The moral of Dr. Voelcker’s remark-and he commended it to the notice of her Majesty’s Office of Works-was that the amenities of oflicial intercourse are greatly sweetened by pleasant surroundings in a pleasant room. That fact, he was afraid, was too frequently lost sight of in the public service. But lie might say that, thanks to the beneficent act of the Treasury, he was shortly to be placed in possession of a building which, he thought, would, in its fittings and appointments, do more justice to, and be more worthy of, the science which they professed. He could not as yet say what his office would be like, but, at all events, he hoped that it would not be unworthy of a visit from them ; and he trusted that its surroundings and comforts would be such that he might look forward to that personal adjustment of such questions as had been referred to, and that he might enjoy the same pleasant facilities for such adjustment as were possessed by Mr. Elliott. He concluded by again expressing his hearty thanks for the manner in which the toast had been proposed and received (loud applause). Mr. T. H. T ~ i m { (President of the Society of Chemical Industry) proposed “ The Editorial Corninittee ” of the ANALYST. The responsibility attached to the carrying on of such an organ as the ANALYST was a very weighty one, and the manner in which that responsibility was borne by those on whom it rested was worthy of high compliment. I n the absence, through illness, of Dr. Sykes, Mr. ALLEN returned thanks on behalf of the Editorial Committee. Mr. CARTELGHE proposed the health of ‘‘ The Honorary Secretaries,” expressing a, sense of hearty appreciation of their labours on behalf of the visitors. Dr. BERKAXLI 111-i.x returned thanks, and the proceedings came to a close.

ISSN:0003-2654    

DOI:10.1039/AN8962100036

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

14 THE ANALYST. ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. FOOD ANALYSIS. Estimation of Tannin in Wines. E. Manceau. ( C ~ / ~ i L ~ ) t . llcizd., 1895, cxxi., 646; through Chem Zeit. Ilep., 1895, 372.)-One hundred C.C. of the wine are put into a stoppered flask, 1 grainme of catgut added, and allowed to stand for a week at 15" C. Twenty-five C.C. are then titrated with a permanganate solution of which 1 C.C. is equal to 0.8 milligramme of gallo-tannic acid, using indigo-carmine as an indicator. A similar titration is carried out on the original sample, the amount of tannin being obtained from the difference. For the catgut the author recommends the employment of moiled violin-strings, which have been washed in dilute alcohol, acid, and water, until they have no further action on permanganate in the cold.F. H. L. Determination of Fat in Milk. H. Tiemana ( ~ I ~ C / L % c k , 18'35, XXiV., 714 ; through Chenz. Zeit. Rel~. , 1895, 372.)-From results obtained at the " Milchwirth- schaftliche Versuchsstation " at Kiel, the author concludes that it is not necessary to adopt any method for the sterilization of samples of milk when Wollny's process for the estimation of the fat is employed. None of the micro-organisms which cause the putrefaction of milk, etc., appear to affect the fat in any way. F. H. L. The Variation in Size of the Fat-globules in COWS' Milk. E. Gutzeit. (Landzu. Jahrb., 1895, xxiv., 539 ; through Chem. Zeit. Rep., 1895, :-3i3.)-The average size of the fat-globules in the milk of any cow is affected by a number of external circumstances.Any sudden change in the weather, the food, or the living-place, may produce considerable alteration, although it is impossible to assign any uniform variation, i.e., any regular increase or decrease in size of all the globules, to any one of these causes. During the whole time of lactation they regularly diminish in diameter. Among cows of the same breed the average size of the particles extending over the whole lactiferous period is fairly constant, and in the milk of each particular individual the globules, whether large or small, possess the same physical and cheniical characteristics. F. H. L. Extraction of the Fat of Cheese for the Purpose of Examination. 0. Henzold. (Milch Zeit., 1895, xxiv., 729 ; through Chem. &it. Rep., 1895, 372. )--Three hundred grammes of the powdered cheese are agitated in a wide-necked iiask with 700 C.C.of 5 per cent. caustic potash, previously warmed to 20" C. After about 10 iiiinutes the cheese dissolves, and the fat floats to the surface, where, by cautious shaking, it may be made to agglomerate in lumps. The liquid is diluted, the fat removed with a spoon, washed in very cold water, then kneaded till as dry as possible, and finally melted and filtered. Experiments show that under this treatment the fat suffers no change in com- position. F. H. L.THE ANALYST. Artificial Colouration of Wine. M. Rinzaud. ( LTniogL I’Imvbaceut iquc, xxxvi., 446 ; through Bzdl. de Z’Ass. ZleZge Chin&., 1895, 231. j-For the detection of artificial colouring matter in wines the author uses sodium peroxide.This acts as an oxidiz- ing agent, completely destroying the colouring matter of a natural wine. Wines coloured by fuchsine, etc., are also decolourized by the reagent, but the colour reappears on the addition of an acid. In making the test 5 C.C. of the wine are treated with 0.10 to 0.15 gramme of sodium peroxide. After the lapse of five minutes, when all colour should have disappeared, several drops of acetic acid are added to acid reaction. C. A. M. Emulsified Lard. A. Goske. (Chem. Zcit., 1896, sx. 21.)-In a recent lawsuit in Diisseldorf it was announced that the purification of lard by iiieans of a current of air raised its iodine number, increased its reaction with Welsnian’s test, and caused it to be slightly reduced by Becchi’s reagent. The author has exaiiiined four samples of lard of known purity, before and after the air-treatment, and is unable to bear out these statements. One sample gave a higher iodine number, one a lower, the others practically identical values. Two samples gave a very faint brown colour with Becchi’s test, in no way resembling cotton-oil, while the others showed no sign of reduction. He also finds that samples of pure lard, which, like these two, give a slight reaction with Uecchi’s reagent, if washed slightly in warm water, no longer yield the least trace of colour on the application of the test. Welsman’s test gave the same results all through. F. H. L.

ISSN:0003-2654    

DOI:10.1039/AN8962100044

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

THE ANALYST. 45 ORGANIC ANALYSIS. Trimethylene Glycol as a bye-product in the Glycerin Manufacture. A. Noyes and W. H. W. Watkins. (Jaw. ,-lrnei.. Chciri. Soc., xvii., 1895,890-891.)- During last winter a firm of soap-niakers in Boston found a difficulty in getting their glycerin to the required commercial gravity. A quantity of the '' light stuff" was sent to the authors for examination, and by fractional distillation t,hey obtained from it about 38 per cent. of a liquid boiling between 214" and 217'C, and having a specific gravity of 1-056 at C. On analysis the formula of this substance was found to be C:;H,O,. I t was therefore trimethylene glycol, which has a boiling-point of 214" C. and a specific gravity of 1.0536 at .!z C. The isomeric propylene glycol boils at 188"-189' C., and has a specific gravity of 1.0403 at Freund (~%!om~t.Chem., ii., 638) showed that trimethylene glycol was one of the principal fermentation products of glycerin, and the authors considered it highly probable that the glycol had been thus produced. It was probably present in the original fat, which consisted largely of house refuse fat, having owed its origin to spontaneous saponification and subsequent fermentation of the glycerin. Its presence in glycerin used for making nitro-glycerin might he dangerous, since 20" 15" 0" 19.4' o' -46 THE ANALYST. it reacts with nitric acid with explosive violence. It would be detected by the glycerin giving a low specific gravity accompanied by a high result by the bichromate tit ration. C. A. M. Examination of Linseed-oil, Varnish, and Oil-colours.R. Hefelmann and P. Mann. (I%uq*tti. Central-H. N . F., 1895, xvi., 685 ; through Chem. Zeit. Hep., 1895, 383.)-The authors advise the use of the butter - refractometer for testing these substances, stating that even small additions of rosin, rosin-oil, metallic resinates, and mineral oil may be recognised by the increased rotation values observed. A number of examples are quoted. F. H. L. Estimation of Sulphur in Organic Compounds. A. von Asboth. (C'hem. Zed., 1895, xix., 2040.)-One gramme of the powdered substance is mixed in a nickel crucible with 10 grammes of dry sodium carbonate and 5 grammes of sodium peroxide. The crucible is heated very gently until the mass falls together and begins to melt ; the heat is then raised until it becomes perfectly liquid.After cooling, the melt is dissolved in water, filtered, hydrochloric acid containing bromine added, and the liquid boiled till all odour has disappeared. The sulphates are then precipitated with barium chloride as usual. I t is necessary to adhere to the proportions given for the sodium carbonate and peroxide, and to heat the crucible very cautiously at first, in.order to avoid loss by spurting. Liquids and extracts may be analysed equally well by this process, after being subjected to evaporation, usually with half of the carbonate, in the crucible itself. When the remainder of the carbonate and the peroxide are added, and stirred in with a platinum wire, a very energetic reaction takes place, but with care no loss need occur.The whole test occupies only about 2 to 2i- hours in the case of solid substances, and the results quoted for potassium thiocyanate are satisfactory. F. H. L. Estimation of Grape or Invert Sugar in Solutions containing Lead. Zamaron. (Uzill. Ass. Chim., 1895, xiii., 346 ; through Cheni. Zeit. Rep., 1895, 348.) -The author finds that the best method of removing lead from liquids in which sugars are to be determined by means of copper solutions is by the aid of ammonium oxalate. The exes6 of ammonia is without influence on the opticity. F. H. L. The Reactions of Digitalin. C. C. Keller. ( B e y . Phum. Ges., 1895, v., 275 ; through C~IC'IIL. Zeit. I~cJJ., 1895, 349.)--Conimercial specimens of digitalin contain four medicinally active principles : digitowuz, a glucoside which can be split up into digitogenin, dextrose, and galactose ; ili~/ztaZin, an amorphous glucoside consisting of digitaligenin, grape-sugar, and digitalose ; d igitalein, a crystallizable glucoside not yet investigated ; and digitoxin, a bitter substance which is not a glucoside.These may be identified by dissolving in glacial acetic acid, adding a drop of ferric chloride so dilute that the solution is only faintly yellowed, and floating it over an equalTHE ANALYST. 47 voluiiie of strong sulphuric acid, when colours are produced at the junction of the two liquids, which are very sharp and characteristic. Digitonin yields a faint rose, rapidly bleaching ; digitalin, a permanent carmine red, having a violet cast even in the presence of -05 milligramme per C.C.; digitalein, an intense red, somewhat like the last, but less permanent. With digitoxin, a greenish-brown is first produced, changing until the acid becomes a brownish-red, while above it appears a bluish- green band, rapidly altering to indigo-blue in colour. This last reaction is also readily obtained on examining the extract or the infusion of digitalis. F. H. L. Valuation of Extract of Cinchona. Van L. Hulsebosch. (Ncr. Plinrm. Ges., 1895, v., 286 ; through ClienL. Zeit. Ilep., 1895, 349.)--To determine the alkaloids, 1 grainine of the extract is moistened with 5 C.C. of water and 5 drops of normal hydrochloric acid in a small beaker, introduced into the percolator, and the beaker rinsed twice with 5 C.C. of water. Ether is added and allowed to act for an hour, in order to reiiiove all soluble matter.A tared flask is then attached, 2 C.C. of normal soda and 3 C.C. of water poured on to the substance, fresh ether added, and, after two hours, evaporated off, the alkaloids dried at 100" C. and weighed. To estimate the cincho-tannates, 10 grammes of the fluid extract are mixed with 10 C.C. of a 20 per cent. solution of sodium acetate in a weighed glass basin with vertical sides. I t is heated on the water-bath till the salts have agglonierated and attached themselves to the walls of the vessel. The liquid is then poured off, the basin rinsed with a little water, the moisture removed with a strip of filter-paper, and the residue dried at 100" C. and weighed. The weight of the tannates should represent at least 12 per cent.of the extract, and they should form, when ground up, a pale flesh-coloured powder. F. H. L. Estimation of Unsaponifiable Matter in Wool-fat. W. Herbig. (L)bzg. PoLyt. Jour., 1895, ccxcvii., pp. 135-141.)-The methods for this estimation are classified by Benedikt into three groups : ( [ L ) Direct saponification and subsequent weighing of the unsaponified matter, (13) Bxtraction of the soap solution with petroleum spirit or ether, ( c ) Extraction of the dry soap with these solvents. Of these processes the first invariably gives too low results, and in the author's opinion all have defects which limit their applicability and influence the accuracy of the results. I n his experiments to find a reliable method, the author tried the influence of solvents on the salts of the fatty acids obtained by precipitating a solution of the potash soap with the chlorides of copper, zinc, cadmium, aluminium, barium, strontium, calcium and magnesium.I n each case they were soluble to a consider- able extent in ether and petroleum spirit. The calcium salt was the least soluble, but satisfactory results could not be obtained. This difficulty was overcome by using pure acetone as the solvent, it being found that the calcium salts were completely in- soluble in it. On this property the following process is based: From oue to 2.5 grammes of the wool-fat are saponified with serninormal alcoholic potash, the excess48 THE ANALYST. of alkali neutralized with standard acid, and the whole washed into a beaker with boiling alcohol.The alcohol is evaporated, the solution heated to about 70" to 75" C., and the fatty acids precipitated with calcium chloride, the amount of which has been calculated from the saponification equivalent. The precipitate is filtered off, well washed with dilute alcohol (1 : 20), and dried on blotting-paper in vacuo. When dry, it is extracted in a Soxhlet extractor with freshly-distilled acetone for six hours, after wbich the acetone is evaporated, the extract washed with ether into a platinum basin, and the ether evaporated, and the residue, which consists of the unsaponifiable matter, and of the esters, which cannot be saponified by the ordinary process of boiling with alcoholic potash, dried st 105" C. and weighed. The chief points to be observed are the absolute purity of the acetone, the fraction boiling between 55.5" and 56.5" C. being used, and the temperature at which the calciuiii salts are precipitated. If too hot they fuse, and if too cold they become slimy, subsequent filtration being almost impossible in either case. I t is also advisable to extract the cork of the extraction apparatus with ether, alcohol and acetone; the errors introduced by the hot alcohol dissolving some of the calcium salts, and by the decoinposition of the latter during filtration, are so very trifling that they may be neglected. The following results were obtained in this way with three samples of wool-fat. Five determinations were made in each case, but only the highest and lowest of these are given here : Wool- fat . Yat used. Grammes. South American 2.1156 New Zealand 2.2145 Russian 2.3340 -- , 9 2.1110 Y , 2.4928 I 9 8.1526 Extract found. Grammes. 1.0261 1.0200 1.0283 1.151@ 0.8704 0.7981 Ash in Extract. Grammeu. 0.0002 0.0001 0~0001 0~0000 omoooO 0*0002 Per cent. uusaponi- fiable matter. 48-5 48.31 46.44 46-17 37-29 37.07 C. A. M.

ISSN:0003-2654    

DOI:10.1039/AN8962100045

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

48 THE ANALYST. INORGANIC ANALYSIS. Method for Distinguishing between Photographic Prints Produced by Development and by Direct Exposure. (fWonzt. Scient., 1895, xlvi., 813,)-It is stated that an ordinary fixing bath of (about) 10 per cent. thio- sulphate containing 0-2 per cent. of ammonium bichromate will not dissolve the image of a chloride-emulsion paper if it has been developed,” but will remove it if it has been obtained by insolation alone. G. F. Jaubert. F. H. L. The Volumetric Determination of Lead. A. 5. Cushman and J. Hayes- (Jozmi. L4?1tci*. Ch772. Soc., xvii., 1895, pp. 901-904.)-Among volumetric In Campbell. methods for the determinatior, of lead that of Schwartz is in very general use.THE ANALYST. 49 this the lead is precipitated as chromate in a sodium acetate solution, standard potassium bichromate being added until a faint red tint appears when a drop of the liquid is brought into contact with neutral silver nitrate on a porcelain plate.The objection to this is that the end point is frequently overrun, owing to the uncertainty introduced by the !.ellow of the precipitated lead chromate. A similar difficulty occurs in Diehle’s modification of Schwartz’s method (Zeit. anal. Chenz., 1880, 306). To obviate this the authors propose the following modification : One gramme of the pulverized ore is digested in an evaporating dish with 15 C.C. of a mixture of nitric and sulphuric acids (2 : 1) until completely decomposed. Ten C.C. more of sulphuric acid are now added, and the liquid evaporated until it fumes freely.After cooling, 10 C.C. of dilute sulphuric acid (1 : 10) are added, and then gradually 40 C.C. of water. The liquid is boiled and filtered, and the residue washed by decantation with the dilute sulphuric acid, as little lead sulphate as possible being allowed to get on to the filter. Twenty C.C. of strong ammonia are then poured upon the residue, after which acetic acid is added to slightly acid reaction. When the lead sulphate is dissolved the liquid is poured through the filter, the paper having been previously moistened with ammonia. The filter is washed with water containing ammonium acetate, and finallj- with hot water. The filtrate is cooled, excess of standard bichromate added from a burette, the precipitate allowed to settle, filtered off, and the filtrate titrated with standard ferrous ammonium sulphate.The method can be carried out in about thirty minutes, and where the ore is known to be free from bismuth and antimony, the lead can be brought into solution by nitric acid alone, and immediately titrated with bichromate and ferrous ammonium sulphate. To test the method, a sample of galena which by gravimetric methods was found to contain 86.0 per cent. of lead was treated as described above. The amount of lead obtained in eight determinations varied from 85-72 to 86.08 per cent., the mean being 85.88 per cent., so that in general it may be said that the results are slightly low. C. A. M. The Estimation of Sulphur and Chlorine by Means of Sodium Peroxide. A. Edinger. (,%it. cinul. C7if?m., 1895, pp. 362-368.) - In estimating sulphur in derivatives of the aromatic amines by the Carius method and by ignition with soda and potassium nitrate, the author found that the resulting barium sulphate required to be purified froiii barium nitrate.To obviate this experiments were made to determine how far bariuiii and sodium peroxides could be relied upon as oxidizing agents. By treating dried copper sulphide in a platinum crncible with barium peroxide and some soda, the amount of sulphur found was 33.7 per cent., as compared with 33.60 per cent. calcu- lated. There was, however, the drawback that the barium peroxide attacked the platinum, and the same objection applied with still more force to the use of sodiunl peroxide. In the latter case a porcelain crucible could be used, and any silicate removed by filtering the warm acidified sodium sulphate solution before precipitating the sulphuric acid.With inorganic sulphides very good results were obtained.50 THE ANALYST. Cadmium sulphide oxidized with sodium peroxide gave 92.20 per cent. of sulphur (theory, 22-10>, and in copper sulphide 33-29 per cent. was found, as against 33-6 per cent. calculated, ,4 further experiment with cadmium sulphide in a graphite crucible gave too high a result (22.7). As a test for the simultaneous estimation of sulphur and chloyine, a mixture was prepared containing calcium sulphide, calcium chloride, and 20.2 per cent. of iron oxide and silica. This was gently warmed over a Bunsen flame with ten times its weight of sodium peroxide and soda. The mass was then treated with quite dilute nitric acid, the insoluble residue filtered off, the filtrate made up to 250 c.c., and the sulphur and chlorine determined in aliquot portions of this. The results obtained were : Insoluble matter, 30.2 per cent.; sulphur, 15.2 per cent.-corresponding to 33.6 per cent. calciuim sulphide ; chlorine, 29.3 per cent. - corresponding to 45.8 per cent. of calcium chloride : total, 99-6. This determinatioa was made in a platinum crucible, but where the insoluble residue is not required porcelain is preferable. Action of Peroxides on Organic Substances.-When barium peroxide is used as the oxidizing agent, the determination can only be made in a platinum crucible. The decomposition of sodium benzene-sulphonate by means of barium peroxide and soda, and the subsequent addition of a little sodium peroside, proceeds quietly, and the mass, when treated with dilute nitric acid, yields no sulphuretted hydrogen.Example : C!,H;SO,.Na. 0.3498 gramme yielded 0~462~5 barium snlphate = 18-10 per cent. sulphur. Sodium peroxide in the dry state acts so energetically on organic bodies that accurate results are impossible. On the other hand, its 3 or 4 per cent. aqueous solution has but little action either in the cold or on heating. This difficulty is over- come by the cautious evaporation of an aqueous solution of the sodium peroxide in contact with the organic substance, and under these circumstances the crucible is not attacked to any perceptible amount. The following method of procedure was adopted : The sodium benzene sulphonate was concentrated with as strong as possible a solution of sodium peroxide.When the mixture had attained the consis- tency of oil the crucible was heated over a very small flame until the ma65 began to darken. A few more drops of the peroxide solution were then added, and finally the crucible and its contents heated on the water-bath in a beaker containing cb concen- trated solution of sodium peroxide. After fifteen minutes the clear solution was acidified with hydrochloric acid, and the sulphur estimated hy precipitation with barium chloride. (Theory, 17-77 per cent.) Results obtained by this process : Sulphur. Calculated, Found, per cent. per cent. Sodium benzene-sulphonate ... 17-17 17 *88 Sulphanilic acid ... ... ... 18.50 18.21 Sodiuiii aniline-sulphonate .. . ... 15.M 14 -10 Equally satisfactory results were obtained in the case of non-volatile chlorine compounds in alkaline solution, and of organic platinum chloride compounds, The weighed double platinum salt was introduced into a highly concentrated scdium peroxide solution, evaporated to dryness on the water-bath, more sodium peroxideTHE ANALYST. 51 added, the crucible gently ignited, and finally heated on the water-bath in a beaker containing sodium peroxide solution. The separated platinum was filtered off, ignited and weighed, and the chlorine determined in the filtrate. Example : Iso- chinolin-benzyl-chloride, chloroplatinate. Calculated, Found, per cent. per cent. Platinum . . . ... ... 23.0 23.1 Chlorine ... ... 35.0 24.9 The author considers that this method, which is applicable to all non-volatile chlorine and sulphur coinpounds, is a great improvement on the so-called Wallach met hod, C.A. M. Analysis of Copper and its Ores. Leaoux. (Trriils. Aim/*. 1u.s.t. Min. Eng., October, 1895; through C'hem. Zcit. Rep., 1895, 372.)-The author has been com- paring the figures returned by a number of laboratories for the amounts of gold and silver existing in conimercial coppers. He finds that the copper contained in the buttons of silver yielded by the dry process, which is usually assuined to compensate for the silver volatilized, varies very considerably, and bears no relation to the weight of silver lost. A combined process of wet analysis and assay is better, therefore, for the estimation of silver, This can be precipitated froiii solutions free from zinc and copper, and subsequently cupelled at a low temperature almost without loss.For gold this double process is not advisable, as some of thr: gold always dissolves during the solution of the copper in nitric acid, causing the rtmlts to be too low ; dry assay is, however, satisfactory. F. H. L. Decomposition of Silicates by Boric Acid. P. Jannssch. (BET., 1895, xxviii., 2822.)-One graiiirne of the finely-powdered silicate is mixed with 5 or 6 gramnies of anhydrous boric acid, and ignited strongly for 15 or 20 minutes. The melt dissolves completely, or with it residue of silica, in hot water or alcohol. The solution is evaporated to dryness, strong hydrochloric acid and methyl alcohol added, and again dried down, when the boric acid volatilizes conipletely as methyl ester, the subsequent analysis being conducted in the usual manner.F. €3. L. Three New Reagents for the Detection of Nitrites. M. G. Deniges. ( J . P h n n . Chiiic., 1895 [6], ii., 289 ; through Clzei/i. Zcit. I i c ~ i . , 1N5, 328.)-(1) By boiling phenol with 31illon's reagent (mercuric nitrite and nitrate) a precipitate is formed, soluble with a red colour in acetic acid. This reaction will detect one part of phenol in two million, and, by it modification, the author has made it available as a test for nitrites. Two solutions are prepared: (a) 1 grarnine of phenol, 4 C.C. of sulphuric acid, and 100 C.C. of water ; (b) 3.5 gramine of mercuric oxide, 20 C.C. of glacial acetic acid dissolved in 100 C.C.of water, 0.5 C.C. of sulphuric acid added, and the whole filtered. Equal parts of the two liquids are mixed together, a few drops of the suspected liquid introduced, and boiled. A red colonr will he formed in the presence of one part of nitrite per 2,000.52 THE ANALYST. (2) Two C.C. of aniline are dissolved in 40 C.C. of acetic acid, and diluted t o 100 C.C. with water. On boiling this solution with some of the liquid to be examined (from 1 drop to 1 0 C.C. 1, a coloration is produced varying from a straw-yellow to a, deep orange, which, on cautious acidification, changes to a red. Chlorates and nitrates have no influence on the reaction, but hypochlorites, hypobromites, free chlorine, and bromine, as well as excess of acid, must be avoided.(3) One gramnie of resorcinol is dissolved in 10 drops of sulphuric acid and 100 C.C. of water. If 4 drops of the liquid under examination are shaken together with 2 C.C. of pure sulphuric acid and 5 drops of the resorcinol solution, the presence of nitrites is shown by a carmine or bluish-violet colour. This reaction will detect 0-01 milli- gramme of a nitrite. F. H. L. A Colour Reaction for Chlorates. M. G. Deniges. ( J o w ~ i . PImwt. Cliim., 1895, [6], ii., 400 ; through C‘hent. Zeit. Rep., 1895, Y71.)--The resorcinol solution, mentioned in the preceding abstract, is also available for the detection of chlorates. A little pure sulphuric acid is mixed with the solution under examination, the whole cooled and shaken. Five drops of the resorcinol reagent are added, the mixture being only shaken again after immersion in cold water.Provided the solution does not contain more than B per cent. of a chlorate, a green colour is produced, recognisable when only 0.1 inilligramme is present. F. H. L. Estimation of Iodine in the Ashes of Seaweed. H. Otto-Jensen. (Special Report to the Technical School at Bergen, 1894-95 ; through Clzem. Zait. Rep., 1895, 371.)-The author has examined the three following methods for the determination of iodine in seaweed, and finds that Duflos’s process-setting free the iodine with ferric sulphate, distilling it into iodide solution, etc.-is the quickest ; but it is difficult to drive over the last traces of the halogen from the retort, the results, therefore, being usually too low. Lasseique’s method--precipitation as palladium iodide-is very exact, but soiiiewhat too delicate for technical laboratories.Griiger’s process yields equally correct results, but the time taken in filtering and washing the inanganese precipitate makes it slower than the first mentioned, although the use of the pump materially hastens the operation. (Groger’s process consists in oxidizing the iodine by iiieans of permanganate to the form of iodate, reducing the excess of the reagent by a few drops of alcohol, filtering off the manganese oxide, adding potassiuni iodide and hydrochloric acid to the filtrate, and estimating the iodine liberated with thiosulphate in the usual nianner.)-Aics. F. H. L. Separation of Cobalt and Nickel. Carnot. ( A m . des Mii~es, 1895, vii., 624; and Berg.u. l i i i t t e i i i i i . Xcit., 1895, liv., 370 ; through Cl~cin. Zed. Bep., 1895, 371.)- Both metals are precipitated with bromine and caustic potash, the liquid boiled, the oxides washed, reduced to the metallic state in a stream of hydrogen, and, after another washing, art’ wtlighed together. They are dissolved in nitric acid, and theTHE ANALYST. 53 solution divided into two portions. One is treated with hydrogen peroxide and potash, precipitating uickvl monoxide and cobalt sesquioxide, the latter being then titrated with potassium iodide and thiosulphate. The other half is neutralized with potash, potassium cyanide added till the precipitate dissolves, then bromine ; the cobalt remaining in solution as cyanide, while the nickel, coming down as sesquioxide, is titrated, in its turn, with iodide. In mixtures containing little cobalt, the ammoniacal solutions may be treated with molybdate solution, the cobalt salt being practically insoluble in the cold liquid, while the douldt. rnolybdate of nickel and ammonium is very soluble. P. H. L. Determination of Silicon in Iron. Liebrich. (StahZ. ZL. E'iseia, 1895, xv., 1058 ; through ~ ! I w u . Xcit. Rep., 1895, 371.)--After the silica has been rendered insoluble in the ordinarj- manner, it is filtered off without much washing, introduced into a platinum crucible, the paper burnt, and three times its weight of acid potassium sulphate added. The crucible is laid on its side, heated gently till all the vapours are given off, then ignited more strongly, the blow-pipe being finally employed. All the graphite burns away, and, after cooling, the melt is taken up in very weak acid, when the silica will be found perfectly pure and white. The solution contains some iron and the titanium of the original sample. F. H. L.

ISSN:0003-2654    

DOI:10.1039/AN8962100048

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

THE ANALYST. 53 L E G A L . IMPORTANT IJECLPIOK WITH REFERENCE TO MILK CERTIFICATES. Hrt;ii Couw o r JUSTICL. (/Ic*Joe~ BIIK. J[-STICE HAWKIKS i i i i d ME. JL.N’ICE KENPIED\..) (Rep;ritd $row the ‘‘ Tinaes ’’ of Jaimury 28, 1896.) 1.0R I UKE YI’I’ELLANT-HASSOI, RESPON1)EST. This was a special case stated by a stipendiary Metropolitan magistrate, and raised the question whether an nndyst’s certificate of milk ought to show what he considers to be the normal proportion of water in milk. Mr. Macmorrnii appeared for the appellant, the inspector; Mr. Morton Smith for the respondent. An information was taken out against the respondent at Clerkenwell Police Court. The offence charged was that he did sell and proceed to deliver on April 21, 1895, to Elias Jones a churn of milk in pursuance of a contract to sell, the same not being of the nature, substance, and qualitg of the milk demanded by the purchaser, in that i t contained 5 per cent.of added water contrary to section 1; of the Sale of Food and Drugs Act, 1875, and of section 3 of the Act of 1879. The facts were these. The respondent sold a churn of milk to Jones on April 24. While it was being $old the appellant, inspector of nuisances for St. Mary, Islington, procured a sample of the milk mid had it analysed by the public analyst. The certificate of the analyst wa8 to the following efYect :54 THE ANALYST. “I . . . . do hereby certify that I received on the 35th day of April, 1895, from Mr. Fortune a sample of milk marked as above for analysis (which then weighed 20 oz.), and have analysed the same, and declare the result8 of my analysis to be as follows : “ I am of opinion that the said sample contained percentages of foreign ingredients as under: 5 per cent.of added water to the prejudice of the purchaser. Observations.-No change had taken place in the constitution of the article that would interfere with the analysis. This sample was handed to me undivided. I divided it into two parts, and one of which parts I returned to the purchaser.’; This certificate was objected to as being bad evidence of the offence charged on the following grounds : (1) That it did not state as the result of the analysis the parts contained in the sample analysed; (2) that it contained statements of fact not authorized by the statutes, which facts should have been proved by sworn testimony and not by certificate.The statement of fact objected to was that he divided the sample into two partB, one of which he returned to the purchaser. I n support of the first objection. it Wits contended that, as milk is composed partly of water, and there is no fixed standard, the analyst should state the exact quantities of the water and other constituent parts, so that i~ respondent might be able to determine whether he would require the inspector to attend for cross-examination, or whether he should appeal to the chemical officers at Somerset House. I n support of the second point, it was contended that if the analyst were permitted to certify other facts than those authorized in the statute there would be no limit to the extent of proof which might be given by the certificate.The magistrate rejected the certificate, and therefore dismissed the information. He, however, granted this case at the request of the appellant. The form of the certificate is given in the schedule to the Act. It was followed for the most part in the certificate in the case-with the exception of the parts objected to. The following note appears in the schedule applicable to the word ‘‘ observations ’’ : “ Here the analyst may insert a t his discretion his opinion as to whether the mixture (if any) was for the purpose of rendering the article portable or palatable or of preserving it, or of improving the appearance, or was unavoidable ; and may state whether in excess of what is ordinary or otherwise, and whether the ingredient materials are or are not injurious to health.I n the case of a certificate regarding milk, butter, or any article liable to decomposition, the analyst shall specially report whether any change had taken place in the constitution of the article that would interfere with the aualysis.” Mr. Macmorran referred to the Food and Drugs Act, lRi5, :W and :;!I T’ict., c. 63, s. 18, and urged that the certificate was good. It was not necessary to set out the constituent parts of the sample. It was enough to show what foreign article was introduced. “ Bakewell v. Davies” (1894) (1 Q.B., 2!)6) showed that if there were words of surplusage they could be left out. Dr. Morton Smith said that “Bakewell c. Davies” showed that if it was a case of abstraction the constituent parts need not be set out, but if i t was a case of adulteration they must be.It was most impoihnt to know what the analyst’s basis of analysis was. It was all the more important in a case where only an addition of 3 per cent. of water was alleged. There way a dispute among scientific men as to what was the proper percentage of water in milk. “Newby t-. Sims” (1894) (1 Q.B., 478). Water was not a foreign ii~greclient. The second point was not really contested. Mr. Macmorran admitted that water was a constituent of milk, but poiuted out that Mr. Justice Hawkins asked whether i t was not the duty of the magistrate to decide the Ought he not, therefore, to be informed of the amount of water in milk which the Mr. Macmorran said that the respondent could always cross-examine the analyst if he The certificate was only prim6 facie Newhy P.Sims ’; the analyst had not followed the form of the *‘added water” was a “foreign ingredient.” case. analyst took as being the normal standard ? wished, and then the standard could be ascertained. evidence. I n the case ofTHE ANALYST. 55 echedule. convict on the certificate of the analyst if it be not called in question. He cited .. Harrison 7’. Richards” (45 J.P., 552) to prove that the justice ought to The Court upheld the magistrate’s decision. Mr. Justice Hawkins went a t length into the various sections and the form of certificate given in the schedule. He thought the certificate here did not conform to the requirements of the Act. It was admitted that milk naturally had water in it, and therefore it was necessary, in his opinion, that the magistrate should know what standard the analyst took. Standards differed greatly ; the magistrate might take one, and the analyst another. To say there was 5 per cent. of “added water” was merely an opinion of the analyst. The justices ought to know upon what percentage he based his calculation. It was not as if water was a substance totally unknown in milk in its pure state. Mr. Justice Kennedy concurred. The certificate was to give substantially the datcr on which the justices coiild act for themselves. It would be wrong to convict on a mere statement that there was 5 per cent. of added water. The analysis should be clear, and afford materials on which the justices and the accused also might know how the results had been arrived at. That was the principle of “Newby 2’. Sims” (1894) (Q.B., 478).

ISSN:0003-2654    

DOI:10.1039/AN8962100053

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

THE ANALYST. 55 R E V I E W . MILK, ITS NATCI~E A S I ~ COMPOSITION. By C. 14. A n i m i N , M.A., D,Sc. (London: The great number of papers referring to milk and milk-products which fill the pages of every volume of the ANALYST, and the lively discussioiis which have ensued whenever a paper of this kind was brought before the Society of Public Analysts, are sufficient proof of the great interest taken by analysts in the subject of milk and the preparations derived from it. A book treating on this subject is sure to attract the attention of analytical chemists among others, who, for one reason or another, wish to inform themselyes about those widely-used substances milk, butter, cheese, etc. It was a happy notion of the author of the book before us “ t o give a short, popular statement of the iiiore important facts of the chemistry and bacteriology of milk,” as there did not exist a work in the English tongue dealing with the science of dairying.The author expresses the hope ‘‘ that the work may possess interest for the genera!. reader as well as for the farmer and the student of agriculture,” and he might well have added ‘‘ for the analyst,” for the latter is very- much helped in the interpretation and application of the results of his labour by some general knowledge of the nature, origin, and mode of iiianufacture of the materials he has to examine. It is not an easy task to write a popular book which at the same time shall, to some extent, serve as a guide to the scientist. The author has well succeeded in solving the problem, although it might perhaps be said that the chemical part could have been solnewhat shortened for the layman, while to the chemist it will not appear entirely satisfactory.There is a good description given of the cow‘s udder, accompanied and made more intelligible by a number of well-drawn illustrations, and followed by a statement of our present views on the formation of milk. Speaking on the composition of milk, the Society of Public -4nalysts’ standard is regarded as reasonable, although, as is Adam and Charles Black, 1895.) Price 3s. 6d.56 THE ANALYST. pointed out, genuine milk may occur which does not come up to that standard. The author holds If that a man selling such abnormal milk should be treated very much in the same way as a man selling adulterated milk.” This opinion, which is shared by many public analysts, is highly objectionable. -1 man selling naturally poor milk may be made answerable for supplying an article not complying with the demands of the law, but he ought not to be punished as a criminal.The statement-in a footnote on p. 24-that in butter-fat glycerin is present to the amount of 4-5 per cent. is not likely to be accepted by chemists. There are a few other points to which objections might be raised, e.g., the average amount of albuininoids present in inilk being given as about 4 per cent. The chapter I ‘ on the causes and conditions influencing the quality and quantity of milk “ is very well written. On p. 59 the formation of a skin on milk heated to 50” C. is erroneously explained as caused by the coagulation of the albumin.The chief constituent of this skin is casein. The occurrence of slowly-rising creain is attributed to an extraordinary change of the nitrogenous matter, by which ‘( a large proportion of the fatty globules becomes free.” Having regard to the very important part which micro-organisnis play in dairying, as helpniates in the manufacture of butter and cheese, as adversaries in producing undesirable changes and decompositions, and as deadly foes in spreading diseases through the agency of milk, much space has been allotted to describe bacteria, their various kinds and forms, and their mode of development in general, and their action on milk, cream, butter, and cheese in particular. I t is a moJt excellent chapter, which inight be read with profit by everyone desirous of informing himself super- ficially on this topic.That the (‘ salt taste ” of milk is wrongly attributed to bacteria, and that in the list of cheeses which are inhabited by niould the famous Stilton has been omitted, cannot detract from the value of this chapter, which is well and profusely illustrated. The following chapters treat on the scientific side of butter and cheese making ; the facts are stated correctly, with few exceptions. -4s one instance of an error, it may be mentioned that the most favourable temperature for the action of rennet is given as 30” C., while it actually is 41” C. In enumerating inetliods for ascertaining the fat in milk, the latest processes have not been taken into account ; and, speaking of the gravimetric determination, the well-known and widely, almost universally, adopted so-called coil process is attributed to Adam, instead of Nr. M. A. Adams. Some people who are ordered to partake of a diet as easily digestible as milk, and who, however, have no particular liking for the latter, will be pleased to be inforined that oysters are practically of the same nutritive value. A number of German, Danish, French, and American works-in the first place Fleischmann’s “ Handbook on Dairying ”-have been much drawn upon for the com- pilation of the book under review. The author freely acknowledges his indebtedness to the authors of those works, from which also a number of illustrations have been taken. P. VIETH. The meaning of this assertion is not clear. The last chapter treats on “milk as food.” DAIRY TNSIWUTE, HAMHLN, HAXOVER. Jtznrcary 7, 1S96.

ISSN:0003-2654    

DOI:10.1039/AN8962100055

出版商:RSC    

年代:1896

数据来源: RSC