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MARCH, 1912. Vol. XXXVII., No. 432. THE ANALYST. OBITUARY. JOHN MUTER. ALL active and energetic men, for whom the working hours are not long enough for the fulfilment of their duties, must feel with Renan thak one of the most astonishing things in human life is its shortness. The thoughts span the bridge between youth and age; the road seemed so long, the real distance traversed is so little. It seems but yesterday since the writer of this notice attended, as a young man, in March, 1876, for the first time, a meeting of the Society of Public Analysts in Cannon Street Hotel. The cover of the first number of the ANALYST was being shown by the Chairman, Wanklyn, to the members, and a paper was being read by Dr. John Muter on the analysis of butter. This was his first meeting with a man who, then already very well known, was one of the founders of the Society ; one of the few who had some practical knowledge of the analysis of drugs and food, and from whom more could be learned than was contained in the then available books on the subjects interesting Public Analysts.Books, indeed, were few and feeble. There was Pereira on ‘‘ Drugs ” and Hassall on (‘ Foods,” both dealing mainly in generalities, and breaking down whenever one tried to dive below the surface of any subject. There was an anonymous work, “Death in the Pot,” a sensational mixture of fancy with some facts, and a little book by Atcherley, with a collection of analyses of commercial articles, ranging from nuts to nightingales’ dung. Knowledge, such as is now amply stored in the tables contained in (‘ Koenig,” or on the shelves that groan with the weight of thirty-six volumes of the ANALYST and twenty volumes of the Zeitschrift fiir Untersuchung der Nahrluiagsmittel had not been born.The little band of men who realised that the co-operation of all practical chemists was necessary in order to carry out the duties imposed upon them by the Sale of Food and Drugs Act that had been passed in 1875, and in the shaping of which they had taken an important share, comprised Duprk, Allen, Wiper, Muter, and Heisch, as the most active of the founders of the Society. The profession of Analytical Chemists was quite small ; indeed, it is scarcely correct to speak of such a profession at that time. The lecturers at various hospitals, the professors a t colleges and the Pharmaceutical Society, some medical men who had taken, as amateurs, to the microscope and the test-tube stand, formed the bulk of the Analytical Chemists in London.Wanklyn, a few years before, had written in the ChemicaE News epoch-making papers on the composition of milk; these had led to long and bitter controversy, which reverberated for years afterwards. The writer of this notice, with Arthur Angel], had published a pamphlet on a distinctionMARCH, 1912. Vol. XXXVII., No. 432. THE ANALYST. OBITUARY. JOHN MUTER. ALL active and energetic men, for whom the working hours are not long enough for the fulfilment of their duties, must feel with Renan thak one of the most astonishing things in human life is its shortness. The thoughts span the bridge between youth and age; the road seemed so long, the real distance traversed is so little. It seems but yesterday since the writer of this notice attended, as a young man, in March, 1876, for the first time, a meeting of the Society of Public Analysts in Cannon Street Hotel.The cover of the first number of the ANALYST was being shown by the Chairman, Wanklyn, to the members, and a paper was being read by Dr. John Muter on the analysis of butter. This was his first meeting with a man who, then already very well known, was one of the founders of the Society ; one of the few who had some practical knowledge of the analysis of drugs and food, and from whom more could be learned than was contained in the then available books on the subjects interesting Public Analysts.Books, indeed, were few and feeble. There was Pereira on ‘‘ Drugs ” and Hassall on (‘ Foods,” both dealing mainly in generalities, and breaking down whenever one tried to dive below the surface of any subject. There was an anonymous work, “Death in the Pot,” a sensational mixture of fancy with some facts, and a little book by Atcherley, with a collection of analyses of commercial articles, ranging from nuts to nightingales’ dung. Knowledge, such as is now amply stored in the tables contained in (‘ Koenig,” or on the shelves that groan with the weight of thirty-six volumes of the ANALYST and twenty volumes of the Zeitschrift fiir Untersuchung der Nahrluiagsmittel had not been born. The little band of men who realised that the co-operation of all practical chemists was necessary in order to carry out the duties imposed upon them by the Sale of Food and Drugs Act that had been passed in 1875, and in the shaping of which they had taken an important share, comprised Duprk, Allen, Wiper, Muter, and Heisch, as the most active of the founders of the Society.The profession of Analytical Chemists was quite small ; indeed, it is scarcely correct to speak of such a profession at that time. The lecturers at various hospitals, the professors a t colleges and the Pharmaceutical Society, some medical men who had taken, as amateurs, to the microscope and the test-tube stand, formed the bulk of the Analytical Chemists in London. Wanklyn, a few years before, had written in the ChemicaE News epoch-making papers on the composition of milk; these had led to long and bitter controversy, which reverberated for years afterwards.The writer of this notice, with Arthur Angel], had published a pamphlet on a distinction78 OBITUARY : JOHN MUTER between butter-fat and other fats, which had been promptly ridiculed by some of his experienced elders. At the meeting in Cannon Street in March, 1876, Muter had confirmed its correctness, and hinted that he had long been aware of these facts. It was not easy to grant to a mere boy that he might have ferreted out some knowledge that had escaped the attention of his elders. In time all these little irritations and jealousies vanished in the common desire for the elucidation of facts, and John Muter became a friend with whom it was a pleasure to consult and co-operate.His father was Professor of Materia Medica in the Portland Street Medical School at Glasgow ; his grandfather was the founder of the Glasgow Apothecaries’ Company. John was born in Glasgow in 1841. He studied at the Andersonian University, Glasgow, at which the writer, a few years later, in 1873, was co-assistant to one of the lecturers with William Ramsay, who had just come, ‘‘ promovirt,” from Tubingen, and while Dr. Thorpe was professor. Muter became assistant to Dr. Penny. For a time he worked for Dr, Hassall, in which position he was later on succeeded by Alfred H. Allen and the writer, all unknown to each other. In 1872 he founded a laboratory of his own under the title South London School of Pharmacy,” after he had for some years earned a living as a peripatetic science lecturer.His school was mainly established in the first instance for the purpose of coaching pharmaceutical students for the minor examination, then a perfectly mechanical matter, Gradually his teaching developed into thorough and exhaustive courses, comprehensive and up-to-date, and a large number of students obtained from him effectual pharmaceutical training. For their use mainly he wrote a book on analytical chemistry, which ran through a number of editions. Many samples of drugs were sent to him for analysis, and even before the Food Acts had been passed he had founded a considerable chemical practice. The Society of Public Analysts was formed while food legislation was being discussed before a Parliamentary Committee.In its formation Wigner and Muter bore the main share. The former was an able and most energetic organiser, the latter the more widely experienced practical chemist. Both were rather looked 6 L down upon” by many of the “pure” chemists who then, more or less openly, despised the mere practitioner ; indeed, often with good reasoo. Hence the Society at its start had by no means the good-will of chemists as a whole; difficulties of multitudinoue kinds, scientific and otherwise, soon arose ; the first President, Dr. Redwood, and several others, resigned ; angry discussions and recriminations filled the air ; but Wigner and Muter held on. When the small and penniless Society started their Journal, after the Chemical News had hospitably for a year published the proceedings, they found that the names of responsible editors were necessary, to stand the brunt of eventual legal action.In the first year Wigner alone figured on the title-page as editor ; from 1877 t o Wigner’s death, in 1884, Wigner and Muter jointly; and thence till 1891 Muter by himself. The Journal had really been started as the organ of the Society and its property, but, as there was no money, Wigner and Muter financed it and gradually became the de facto if not dejure owners. John Muter came from a pharmaceutical stock.OBITUARY : JOHN MUTER 79 It was far from easy at that time to conduct and fill a monthly journal mainly devoted to food analysis, No other society existed in the world similar to the Society of Public Analysts ; abstracts were not to be had except quite occasionally; original matter had to be created by a few, somehow. Almost every month the energetic secretaries of the Society sent urgent ‘‘ whips ” to a few active members, who, not then overburdened with the duties of their profession, but rather rich in unprofitable time, had ideas and energy and could work up new matter for the meetings.DuprB, Allen, Muter, Wigner, the writer, and one or two others, were the main stays of the young Society and its Journal. Thus, gradually systematic and scientific food analysis was evolved, full of weaknesses and faults of course, but yet infinitely better than anything previously available. Food legislation in other States of Europe and in America followed, and with it the co-operative work of an army of chemists, opening flood-gates of food analytical literature.DuprB, as the first constitutional President of the Society, was followed in 1879 by Muter, who contributed a considerable number of papers on all sorts of practical subjects, many being of more or less ephemeral interest ; others-like his papers on the separation of oleic acid from saturated fat-acids, his method for the estimation of glycerine, on the analysis of condensed milk-of more lasting value. H e took an active and instructive share in the discussion of the papers read before the meetings, and his fund of merrimeni; and jollity found full scope at the “ informal ” adjourn- ments after the meetings at Burlington House, that were invented very early in the history of the Society by the present historian.None of the old members will forget the informal Annual Meetings, not then the serious, staid full-dress functions into which they have inevitably grown-the meetings at which Allen sang his own compositions, Sykes fiddled, Jobn Newlands recited about Garibaldi, and Vieth and the writer duetted raucous German student songs, and Muter, by request, gave us “The Merry Little Fat Grey Man.” All the jolly old meetings, getting dim in the mist of time. . . . The fermentation among chemists that started with the birth of the Society led, in 1877, to the foundation of the Institute of Chemistry. Muter resolutely opposed this, for what were then good reasons. The founders of the Institute were largely academicians out of sympathy with the work and the aspirations of the chemical practitioners, as the years of unrest that followed in the Institute of Chemistry clearly proved.Yet gradually both the Society of Public Analysts and the Institute got over their turbulent boyhood years and grew into lusty adultness, supporting each other and raising a bounteous crop of facts and of men-a new vigorous pro- fession that is a power in the land, a promise for the future of England. Muter in time became a, fellow of the Institute and served as Censor from 1896-1898. Muter’s journalistic energies were gradually overwhelmed by his ever-growing responsibilities, and in 1891 the Society reoognised that the Journal could no longer remain under the private guidance of its honoured Past-President. It was accord- ingly reacquired by the Society, and has since remained under the direction of the Publication Committee, which is directly responsible to the Council. After that time the members saw little of Muter, whose school, converted into a, limited liability company, required much of his energy. He also held the appoint-80 PROCEEDCNGS OF THE SOCIETY OF PUBLIC ANALYdTS ments of Pablic Analyst for Bermondsey, Lambeth, Newington, Rotherhithe, Southwark, and Wandsworth-in fact, for the greater part of South London-and €or part of Lincolnshire. His private practice was extensive, and included the advisorship of public bodies like the Metropolitan Asylums Board. He died on December 19, 1911, at Worthing. OTTO HEHNER.

ISSN:0003-2654    

DOI:10.1039/AN9123700077

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

80 PROCEEDCNGS OF THE SOCIETY OF PUBLIC ANALYdTS PROCEEDINGS OF THE SOCIETY OF PUBLIC ANALYSTS AND OTHER ANALYTICAL CHEMISTS. THE Annual General Meeting of the Society was held on Wednesday evening, February 7, in the Chemical Society’s Rooms, Burlington House. The President, Mr. E. W. Voelcker, A.R.S.M., F.I.C., occupied the chair. The minutes of the previous Annual General Meeting were read and confirmed. Mr. J. H. B. Jenkins, F.I.C., and Dr. R. Lessing were appointed scrutators of the ballot papers for election of Officers and Council for 1912. The HON. T ~ ~ ~ ~ ~ ~ ~ ~ p r e s e n t e d the accounts of the Society for 1911. These were adopted, and votes of thanks passed to the Hon. Treasurer, Auditors, and Hon. Secretaries. On the motion of the PRESIDENT, a voteof thanks was passed to the President and Council of the Chemical Society for allowing the Society the use of their rooms at Burlington House during the past year.Mr. T. Macara, F.I.C., and Mr. R. G. Grimwood, F.I.C., were appointed Auditors of the Society’s accounts for 1912. The PRESIDENT having delivered his Annual Address, On the motion of Mr. OTTO HEHNER, F.I.C., seconded by Mr. W. J. DIBDIN, F.I.C., a vote of thanks was accorded to the President for his Address and for his services in the chair. The PRESIDENT briefly acknowledged the vote of thanks. The scrutators having reported the result of their examination of the ballot The PRESIDENT announced the election of Officers and Council for 1912 as President.-L. Archbutt, F.I.C. Past-Presidents (limited by the Society’s Articles of Association to h’ight in Number).-Edward J.Bevan, F.I.C. ; Bernard Dyer, D.Sc., F.I.C. ; Thomas Fairley, F.I.C.; W. W. Fisher, &LA., F.I.C. ; Otto Hehner, F.I.C. ; R. R. Tatlock, F.I.C.; E. W. Voelcker, A.R.S.M., F.I.C. ; J. Augustus Voelcker, M.A., B.Sc., Ph.D., F.I.C. Vice-Presidents.-W. H. Willcox, M.D., B.Sc., M.R.C.P., F.I.C. ; Arthur R. Ling, F.I.C.; John E. Stead, F.R.S., F.I.C. Hon. Treasu,rer.-H. Droop Richmond, F. I.C. Hon. Secretaries.-A. Chaston Chapman, F.I.C. ; P. A. Ellis Richards, F.I.C. papers, follows :ANNUAL ADDRESS O F THE RETIRING PRESIDENT 81 Other Members of Council.-E. Richards Bolton; R. M. Clark, B.Sc., F.I.C.; J. Connah, B. Sc., F.I.C. ; J. Evans, F.I.C. ; Charles A. Hill, B.Sc. F.I.C. ; E. Hinks, B.Sc., F.I.C.; G.T. Holloway, A.R.C.Sc., F.I.C.; G. N. Huntly, B.Sc., A.R.C.Sc., F.I.C. ; G. W. Monier-Williams, B.A., Ph.D., F.T.C. ; F. Wallis Stoddard, F.I.C.; S. R. Trotman, M.A., F.I.C. ; S. A. Woodhead, M.Sc., F.I.C. The monthly meeting followed the annual general meeting, the newly elected President, Mr. Archbutt, being in the chair. The minutes of the previous ordinary meeting were read and confirmed. Certificates of proposal for election to membership in favour of Mr. H. Hawley, M.Sc., and Miss M. Gazdar, B.Sc., A.I.C., were read for the second time; and certificates in favour of Messrs. Maurice E. Balston, M.A. (Cantab.), Buckland, Maidstone, analyst to Messrs. W. and R. Ralston, paper manufacturers, Maidstone; Howard A. Caulkin, B.Sc. (Lond.), F.I.C., Mona, Villa, Spencer Road, Belper, assistant chemist to the Midland Railway Company ; and Charles Reginald Wilkins, B.Sc. (Lond.), 40, Church Lane, Hornsey, N., assistant to Messrs. Redwood and de Hailes, were read for the first time. Messrs. S. G. Agar, G. S. Barton, S. W. Bridge, R. V. Briggs, F. C. Dyche- Teague, B.Sc., A.I.C., F. A. Mason, W. B. Saville, and G. A. Stokes, were elected members of the Society. The following papers were read : 6‘ The Souring of Milk,” by H. Droop Rich- mond, F.I.C., and H. C. Huish. (‘ Notes on the Determination of Butter Fat and Cocoanut Oil in Margarine,” by F. W. F. Arnaud, F.I.C., and H. Hawley, M.Sc. ; and ‘( A Flour Improver,” by Edward Hinks, B.Sc., F.I.C.

ISSN:0003-2654    

DOI:10.1039/AN9123700080

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

ANNUAL ADDRESS O F THE RETIRING PRESIDENT 81 ANNUAL ADDRESS OF THE RETIRING PRESIDENT. (Delivered at the Annual General Meeting, February 7, 1912.) THIS evening I have to address you for the last time as President of the Society, and, until comparatively recently, I was in hopes that I should be able to announce that during the year 1911 we had not lost any of our members by death. Unfor- tunately, these hopes have not been realised, and I have to record the death of three very old members of the Society-Mr. McCowan, Mr. Sanford, and Dr. Muter. Mr. McCowan was a life member, who invented a new method for the manufacture of caramel. Possessed of exceedingly wide knowledge, he was at once a practical brewer and an accomplished inorganic chemist, having devised several processes for dealing with ores.Mr. Sanford was a public analyst, who had devoted much of his work to the chemistry of explosives. By the death of Dr. Muter, a link with the past history of the Society is severed. At the time of his death Dr. Muter was the senior Past-President of the Society, having held office in 1879-80. In 1877 he was, with the late Mr. Wiper, joint- editor of the ANALYST, and on the latter’s death i n 1884 he became the sole editor82 ANNUAL ADDRESS OF THE RETIRING PRESIDENT and proprietor until the year 1890, when the Journal passed into the hands of the Society itself. Although of late years he had not kept up any active participation in the affairs of the Society, his pioneer work will always gratefully remain in the memory of his colleagues. We hope to have an interesting memoir of him from the pen of one who was intimately associated with his work.I am glad to say that we have lost only one member by resignation, while twenty-three new members have been added to our roll, and the election of eight other new members takes place this evening. This, although not a large increase, is a satisfactory one, and our total membership is now over 400. Although necess- arily our membership is restricted, there are still a number of men in official positions and in professional work whom we would welcome into our ranks, and whose inclusion would be a source of strength. At no time than now was it more necessary that the profession of analytical and consulting chemists should be drawn together in a united effort to uphold and improve the position of its members, and to resist the attempts, which are all too prevalent, of reducing our profession to the level of a competitive trading business, I n my last address I referred to the lamentable results brought about by the insane competition for official positions under the Food Acts.I am glad to say there are signs that there is a better appreciation of the mischief that is done to the whole profession by analysts agreeing to undertake such responsible work at fees incompatible with its honest performance or with decent remuneration. No one, I submit, can seriously contend that the Public Analyst’s remuneration is excessive, or even liberal. It is based largely on the objectionable principle that the holder of an appointment must be content with official “sprats,” so that he may have the chance of catching remunerative “ whales.” As we all are too painfully aware, the fee mentioned in the Act, as chargeable to individual members of the public wishing to make use of the services of the Public Analyst, has in most cases come to be the maximum fee paid by Local ‘Authorities, in spite of the fact that the advance of knowledge has been utilised by the (‘ scientific adulterator ” in such a way as to vastly increase the labour of detection of adulteration.Another very serious attack on the position of the Public Analyst and of the unofficial analyst is revealed by the action of some County Councils in establishing laboratories of their own, where analyses are carried out either gratuitously or at purely nominal fees.The system of County Authorities appointing a (( whole-time ” officer for carrying out the work required by them is one which, as I stated in my previous address, has “come to stay,” and it cannot be denied that there is a good deal to be said in its favour ii carried out on proper lines. But the establishment of a municipal or county laboratory at the expense of the ratepayer on the lines of a municipal trading concern is highly objectionable. I n the most recent case in point a County Authority has established a Bacterio- logical and Chemical Laboratory under the direction of the Medical Officer of Health, for the examination of waters and the solving of questions arising in connection with sanitary matters and food-supplies.This work had previously been carried out by the Public Analyst for the county, who is thus faced with a serious loss of his professional income.ANNUAL ADDRESS OF THE RETIRING PRESIDENT 83 We, as the society representing the Public Analysts of the country, have strenuously fought against the principle that the work of the Public Analyst can be properly merged in that of the Medical Officer of Health. The work of the latter officer ought to be outside the chemical laboratory, and his knowledge and training- save in rare instances-is utterly inadequate to make it desirable that he should have control of a chemical department. Unfortunately, in the past, the powers that be did not see things in this light, but the Local Government Board has now shown that it is in sympathy with our views; and, by refusing to confirm dual appoint- ments, has done much to discourage a practice injurious alike to our professional and to the public interests, Not only in this country, but in our overseas dominions, is this question a serious one, for I understand that it is proposed to place the Government Chemical Laboratories of one of our dominions under the control of a Medical Officer, in spite of the fact that the work of the Department consists to a large extent of metallurgical and mineral investigations.During the past session, thirty-five papers were read at the meetings of the Society, and these-with a few exceptions-have been published in the ANALYST. I t is in connection with these few exceptions that I have a serious complaint to make.Last year I appealed to members to loyally support our Society by reading at our own meetings papers on subjects in which we were closely interested. I t is impossible and unreasonable to expect that papers should always be read solely with the pure love of advancing knowledge and without any desire that some personal advantage should come to the author. A hard-and-fast line, however, must be drawn at papers read for the purposes of self-advertisement, or for trade purposes. In the cases to which I refer, papers were read at our meetings and simultaneously sent for publica- tion to Trade Journals interested in pharmaceutical matters. We, as a Society, rightly object to be I‘exploited” in this way, and I trust that we shall have no repetition of it.In referring to the question of advertisements, I am glad to say that I think there is a growing feeling that the practice which, in the past, has led to so much abuse- that of giving certificates for the purposes of trade advertisement-is one unworthy and discreditable to our profession. It is very necessary that the Public Analyst should be especially careful in the matter of the reports that he gives, for, not only is he liable to be exploited by the astute advertiser under circumstances which, one must admit, give some excuse for it, but he may-as a recent instance shows-be put in the position of being compelled to take legal action to prevent the unauthorised use of his name in advertisements, or else leave himself open to the suggestion that he has, for a consideration, allowed his name to be so used.I am very glad that one of our most prominent members has had the courage and the public spirit to take legal action in ‘order to stop such proceedings. The position of a Public Analyst would be intolerable if the reports which he has to make in the course of his official duties were liable at any time to be utilised by the pushing advertising trader. I am afraid that in some cases Public Analysts are too easily cajoled into allowing their names to be used under the plea that the matter is one of great public and national importance, and that, by so doing, they are giving valuable assistance in the cause of the health and welfare of the nation. Such popular causes as the stamping out of84 ANNUAL ADDRESS OF THE RETIRING PRESIDENT the great white peril-consumption-have furnished an example of how a Public Analyst may be, no doubt unwillingly, associated with a most unpleasant and unsavoury suggested treatment for this disease.The great popular movement engineered by the Press in favour of (‘ Standard Bread,” and blessed in its inception by a manifesto signed by several distinguished medical men, is a very good example of the hollowness of most of these movements. They serve the purpose for which they are started, and bring grist to the mill of the enterprising advertisers and advertising agents. Such questions as those of sophistication of flour, the composition of baking powders, and the alleged injury which has been done to the health of our working population by the use of ‘‘ white ” flour instead of “ standard ” flour, have been inves- tigated in the laboratory of the Local Government Board, and interesting reports have been issued which have served to place these matters further on a sounder scientific basis, and they have done much to discount the alarmist, and, in a great measure, unfounded statements of the eminent medical authorities who have allowed themselves to be so exploited.I must again congratulate our Honorary .Treasurer on the very clear financial statement which he has laid before us, and upon the careful manner in which he husbands our resources. It will be noticed that this year we have in our accounts the item “Legal Expenses.” This is an item we never like to see if it is possible to avoid it, but this year the Council felt obliged to go to some expense in opposing an application which was made by the Royal Institute of Public Health to grant that Institute a Royal Charter.There are two points in connection with our expenditure which will require attention in the near future. The first is that the growing increase in the cost of our Journal is every year greater than the increase in the income of the Society from the subscriptions of new members, Our policy has been-rightly, I think-to spend as much as possible on our Journal, consistent with maintaining a proper reserve of accumulated funds. The increase in our Journal is shown by the fact that the volume for 1911 contains forty-eight more pages than that for 1910. There have been 39 Papers, occupying 128 pages, and 817 Abstracts, Reviews and Reports, occupying 484 pages in all, as against 34 Papers and 662 Abstracts in 1910.I t is an increasingly difficult task to wade through the enormous mass of scientific literature which steadily accumulates, month by month, and to successfully pick out for recording in the ANALYST, only that which is good, rejecting the indifferent and bad. The Society will, I am sure, gratefully recognise the care and zeal which our Editor, Mr. Julian Baker, shows in keeping up and improving the high standard of our Journal. Our Research Fund-which I am glad to see has received further financial support-is the means of providing valuable matter for our Journal, and some interesting investigations have been completed and the results published in the ANALYST during the past year, while a number of other investigations are still in hand. I n the end the Privy Council did not advise the granting of the Charter.ANNUAL ADDRESS OF THE RETIRING PRESIDENT 85 The second point in future expenditure to which I would refer is in connection with secretarial work.To our honorary officers, and especially to our senior Hon. Secretary, Mr. Chapman, on whom the main part of the secretarial work has fallen, the Society owes a deep debt of gratitude for the time and labour which they have so constantly and ungrudgingly devoted, gratuituously, to the affairs of the Society. When we were a smaller Society, it waB possible to cope with the secretarial work without unreasonable expenditure of time and money, but now, when the mere routine work alono involves the sending out of over 400 notices every month, I feel very strongly that it is the duty of the Society to make provision to relieve our Hon.Secretaries of a burden which has involved them in considerable annual expense. I n the coming Session of Parliament two Bills, which will be of special interest to us, are to be introduced-one, the ‘‘ Milk Bill,” which the President of the Local Government Board will bring forward, the other, Lord Clinton’s “Sales for Agricultural Purposes ” Bill, which has already passed the House of Lords. With regard to the former, the President of the Board of Agriculture has quite recently indicated what he thought should be the guiding principles which should dominate the Bill. In the first place, no milk which was likely to breed disease should be sent into towns; that farmers should not be subject to prosecution for faults over which they had no control ; and, lastly, that, if prosecutions took place, they should be civil and not criminal.The President of the Board further stated that all that the consumer had a right to expect was that he should get pure milk as it comes from the cow. Unfortunately, the attitude of the Board as to standards for pure milk is eminently unsatis- factory, and, having in 1901 issued the “Sale of Milk Regulations,” which fixed the standards, they appear now to be anxious to repudiate them. I n the Annual Report for 1910 of the Intelligence Division of the Board of Agriculture it was stated that the Board did not require that milk should contain 3 per cent. of fat, and that, generally speaking, it was no offence against the Food and Drugs Acts to sell milk that falls below the limits mentioned in the “Sale of Milk Regulations.” If this be so, what is the use of having any Milk Regulations at all? The Board have had a great deal of pressure put upon them, especially by farmers in the North-East of England, to lower the already very low standard which has been fixed, and no doubt this is the reason of the Board’s action in the matter.When one considers the labour that was expended in connection with the milk inquiry previous to the issue of the Sale of Milk Regulations, it seems incredible that the Board of Agriculture should countenance any lowering of the standard for Milk, a course of procedure which, while, no doubt, of benefit to the pro- ducers of inferior milk, would inflict a grave injury on the public in general.To suggest that everything should be regarded as “pure milk,’’ simply because it was what the cow had yielded, is most dangerous. The suggestion that prosecutions in the case of milk should be removed from the criminal courts, appeals in many cases to one’s sense of fairness, but I cannot see why the milk producer alone should be exempted from the odium which attaches to an appearance as a defendant in a police court. Far too much stress is being laid upon the point that the regulation of the quality of a milk-supply is beyond the86 ANNUAL ADDRESS OF THE RETIRING PRESIDENT control of the producer, and, while admitting that, under certain circumstances, it may be a hardship for an honest producer to be summoned in a criminal court, it must not be forgotten that it is the duty of a man who produces milk for sale to see that it complies with the very moderate requirements at present laid down.By proper selection and treatment of his cows, there should be, generally speaking, no difficulty at all in the matter. The L L Sales for Agricultural Purposes ” Bill introduces several alterations to the Fertilisers and Feeding Stuffs Act of 1906, among the principal ones being the abolition of the veto of the Board of Agriculture upon prosecutions, and the exten- sion of the time during which samples may be taken and prosecutions instituted. The principal alteration affecting analysts under the Act is that further particulars are required to be given in the invoices of articles sold for use as food for cattle or poultry. Under the proposed new Act it is suggested that the percentage of 6 L soluble carbohydrates ” shall always be stated.I think it should be pointed out that the figure for the percentage of soluble carbohydrates is only a difference item, and, to arrive a t it, it is necessary to quantitatively determine five other classes of bodies in every sample examined, whereas at present the determination of two only is required in samples submitted under the Act. This should certainly call for the revision of the fees which are at present deemed to be adequate remuneration to the analyst by some of the local authorities in the kingdom.The whole tendency of the action of the authorities administrating both the ‘‘ Sale of Food ” and ‘L Fertilisers and Feeding Stuffs ” Acts has been to throw an increasing burden upon analysts, and even in the matter of the quarterly returns that have to be made to the Local Government Board and the Board of Agriculture additional information is constantly being re- quired. In cases where preservatives are found in any article of food, the exact percentage is constantly asked for, and where samples of milk have been reported on as falling below the limits of the Sale of Milk Regulations, detailed particulars of the analysis are demanded. While we are ready to place all information at our disposal in the hands of the authorities, I think it would be only fair that proper recognition should be given to the increased work which is now thrown on the Public Analyst.With regard to the question of preservatives, I would only say that it seems extraordinary that legal effect has not yet been given to the recommendations of the Committee on Preservatives, and which were reported no less than eleven years ago. I t is to be hoped that ere long a serious attempt to place our Food Acts on a really satisfactory basis will be carried out by the Government. The proceedings of the Congress which was held in 1910 in Paris, at which we were represented by our Hon. Secretary, Mr. Chapman, have been published recently in the ANALYST, and I understand that, in all probability, a further Conference to discuss the question of the Uniformity of Methods of Analysis of Foodstuffs will be held.I have now to relinquish this chair, and, in introducing my successor, Mr. Archbutt, I heartily congratulate the Society upon having secured the services of one who has been so long closely associated with and interested in our affairs. Mr. Archbutt is, as you all know, a distinguished chemist, with a very wide field ofANNUAL ADDRESS OF THE RETIRING PRESIDENT 87 knowledge and experience. As chemist to one of our great railway companies, he has distinguished himself by many important investigations on subjects of vast indus- trial importance, and, incidentally, although he is not a, Public Analyst, his services have been largely requisitioned in connection with work which belongs to this branch of the profession. Mr. Archbutt has the distinction of being the first President of this Society who has, I believe, never held the post of Public Analyst, and I think that it was a, very happy suggestion that the gradual enlargement of our horizon- which a few years ago resulted in our incorporation as a Society which embraced all branches of the analytical profession-should now be marked by the election of Mr. Archbutt to the presidential chair. I now come to the most difficult part of my address, and that is to adequately express to you how deeply I appreciate the honour that has been conferred upon me in placing me in this ehair for two years. I vacate it with the greatest possible regret, but I shall always look back with pleasure on the period that I was per- mitted to occupy it. From the general body of members I have received nothing but kindness, and I cannot sufficiently thank my colleagues on the Council-and especially the honorary officers-for their help and support always cordially given me. Though relegated to the list of (( have beens,” I shall always continue to carry out what has been my great object throughout my official connection with the Society-that is, to do everything I can to promote the welfare and position of the Society and of our profession.

ISSN:0003-2654    

DOI:10.1039/AN9123700081

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

88 BROWN : THE ESTIMATION OF SMALL QUANTITIES THE ESTIMATION OF SMALL QUANTITIES OF ESSENTIAL OILS IN SPICES, ETC. PART 11. BY J. A. BROWN, F.I.C. (Read at the Meeting, December 6, 1911.) IN a previous paper (ANALYST, 1910, 34, 392) I described a, dry-distillation-com- bustion process for estimating the essential oils in carraway and cinnamon spices. The method has now been applied to some other essential oils with the following results * Coriander . . I Cardamom .., Rosemary .., Eucalyptus . . , Aniseed ... Bay ... ... Juniper . . . Cedar . . . ... Santalwood . . . Origani ... Black pepper Pimento ... Carbon Value. 75 73 79.5 72 77 76 83 5 i:} 83 -5 82 79.5 85 73 Temperstur, of Volatilisa tion. 140' C. 140' c. 140" C. 140' C. 150' C. 150" C. 150" C. 160' C. 160" C. - - Average Time of Experiment 1 hour.9 hour. 9 hour. - I - Correction. None. 9 9 7 9 9 , Deduct 0.1 per cent. oil for every 4 hour's heating. Deduct 0-1 per cent. oil for every 4 hour's heating. Add one-sixth oil found, and deduct 0.15 per cent. for 2 hour's heating. Add one-eighth oil found, and deduct 0.25 per cent. for 2 hour's heating. Add one-sixth oil found. - - Essential Oil in Spice. Per Cent. 1 -02 0.60 1.40 - { 2; 0.75 EucaLYPTus.-h the case of three oils from different sources the carbon values were obtained lower than would be expected on theoretical grounds supposing the composition to be mainly terpenes and eucalyptol. The third result given was from a sample of oil guaranteed to be from Eucalyptus globulus. ANISEED and BAY require a deduction to be made from the percentage of oilOF ESSENTIAL OILS IN SPICES, ETC.89 found, to allow for a slight amount of destructive distillation. When spices have to be heated above 140' C. to volatilise the essential oil, a small allowance has to be made for destructive distillation. CEDAR, JUNIPER, and SANTALWOOD, containing more difficultly volatile oils, require a temperature of 150° to 160° C. There is a tendency to resinify under the conditions of the process. Thus, oil of cedar showed unburnt residues of 12.6 and 13 per cent., and santalwood 16 per cent. Juniper berries showed a similarity to carraway-seed (Zoc. czt.) in that, after drying at looo C. until constant in weight, further oil-vie., 0.50 and 0.72 per cent.- was obtained on combustion. A sample of spent berries supplied to me by a distiller gave 0.15 per cent., which proves the comparative inefficiency of ordinary laboratory methods compared to those of the distiller who uses superheated steam.GINGER.-After repeated trials, the method had to be abandoned, owing to the ease with which this oil resinified. It is hoped to apply the process to the estimation of nicotine in tobacco and oil of mustard in mustard. I have to thank Messrs. Stafford, Allen and Sons, and Mr. J. C. Umney for supplying me with samples of oils, etc., and also Dr. Woollatt for help and advice. Santalwood appears to be the only exception. DISCUSSION. Mr. E. J. PARRY considered that this method was open to criticism, on account of the large variations which occurred in the constituents of many essential oils.For instance, in the eucalyptus oil of the British Pharmacopoeia, the proportion of eucalyptol was liable to vary at different times. There was rarely less than 50 per cent., but most of the genuine oil of the present year contained 75 or 80 per cent. About thirty constituents had been isolated from various eucalyptus oils. The terpenes would contain about 88 or 89 per cent. of carbon, and the less oxygenated constituents from 78 to 80 per cent., so that one might have 75 to 80 per cent. of eucalyptol with a carbon value of 88 or 89 per cent., and the remainder with a carbon value varying from 78 or 79 to 88 or 89 per cent, The result was that a carbon figure of, say, 72, 73 or 74 might ,mean almost anything. The position was exactly the same with regard to bay oil, rosemary oil, and many others.Mr. A. CHASTON CHAPMAN remarked that Mr. Brown's process was inrealityone for determining certain volatile constituents of spices-not necessarily the actual proportion of essential oils present. Bay oil, for example, to which allusion had been made, underwent considerable resinification on exposure to air, and this would, of course, very considerably diminish the proportion of volatile constituents obtained by the process. There could be no doubt that for certain purposes the method was a very useful one, but it seemed to him (Mr. Chapman) that it would be very dangerous to attempt to put it forward as a general method for distinguishing between genuine and exhausted spices, since there might be little or no difference between an exhausted sample and a sample in which a considerable proportion of the constituents of the essential oil had become converted into non-volatile matters by exposure to the air.90 HINKS: A FLOUR IMPROVER Mr.C. A. HILL remarked that to speak of “eucalyptus oil” was not definite, and drew attention to the variation in the proportion of eucalyptol. I n Tasmanian (globulous) oil it was usually from 55 to 60 per cent., whilst in Australian oil it was often as much as 80 per cent. Mr. H. E. BURGESS said that he had found that, by extracting the spice with petroleum ether, and determining the refractive index, a very good indication was obtained of the quantity of essential oil present. All analyticai methods for this purpose were, however, liable to such errors as had been mentioned, and probably the only way in which a true indication of the percentage of essential oil could be obtained was by actually distilling a considerable quantity under manufacturing conditions.The CHAIRMAN (Mr. LING-) remarked that from the discussion it appeared that the weak point in the method was the application of a constant factor derived from what was supposed to be a typical oil to an extract that varied in composition according to the age of the spice. He should like to ask if Mr. Brown had tried heating the spice under reduced pressure. In this way resinification might to some extent be prevented. Mr. BROWN said that he had found combustion under reduced pressure to be of very little advantage-not sufficient to compensate for the additional trouble and difficulty of manipulation which it involved. With regard to Mr. Parry’s remarks, he would point out that the estimations in the spices were made under exactly the same conditions under which the carbon figures were obtained, so that whatever error there might be would be the same in each case. As he had mentioned in the previous paper (ANALYST, 1910,34, 392), the carbon figure did not seem t o be affected to any great extent by variations in the proportions of the different constituents of the oil, and, in cases in which the proportion of essential oil was small, such differences would, he thought, not be material. Of course, however, it was not suggested that the method gave more than a fairly close approximation to the truth.

ISSN:0003-2654    

DOI:10.1039/AN9123700088

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

90 HINKS: A FLOUR IMPROVER A FLOUR IMPROVER. BY E. HTNKS, B.Sc., F.I.C. (Read at the Meeting, February 1, 1912.) AN article forming a recent addition to the number of substances sold as flour improvers consists of potassium persulphate. According to the directions it is to be added to flour in the proportion of from 8 to 1 ounce to the sack of flour--i.e., about 1 of persulphate to from 10,000 to 5,000 parts of flour. The drypersulphate is simply mixed with the flour. It is claimed that by such treatment stronger loaves and loaves of better colour are obtained, more water can be absorbed in the doughing process, and, further, that the only residuum in the loaf as a result of the treatment is 5t minute proportion ofHINKS: A FLOUR IMPROVER 91 8; harmless salt, which is a normal constituent of wheat and of many drinking waters.The presence of persulphate in the flour may be readily detected by the reaction with benzidine (Rothenfusser, ANALYST, 1909, 34, 37). An alcoholic solution of benzidine gives a blue colour with extremely dilute solutions of persulphate, the limit of delicacybeing 1 part in about 1,000,000 parts of water; but on applying this test to aqueous extracts of flour the reaction is much less delicate, and an extract of flour containing 1 part of persulphate in 5,000 parts of flour (the greater strength recommended), fails to give the reaction. Much smaller quantities than this, how- ever, may be detected by making a paste of the flour with a small quantity of water and at once pouring the benxidine solution over the paste.The benzidine picks out the particles of persulphate and develops the blue colour round each particle. By proceeding .in this manner, flour containing persulphate in the proportion as recom- mended gives strong reactions, and the limit of delicacy depends practically only on the quantity of the flour taken. With laboratory preparations carefully mixed and sieved, 5 to 10 grms. of flour with 1 of persulphate to 100,000 will, as a rule, show the reaction. A convenient benzidine reagent is a 2 to 3 per cent. alcoholic solution. Mixtures of persulphate with flour gave the reaction with no apparent diminu- tion of intensity after standing for three months. The persulphate may be separated from the flour by suspending in carbon tetrachloride and centrifugal action, the benzidine being applied to an aqueous solution of the deposit. Further, the salt can be quantitatively determined by centrifugalising the suspension of flour in carbon tetrachloride, treating the deposits with small quantities of water and again centrifugalising or filtering to remove small quantities of flour unavoidably left in the tubes, warming with potassium iodide and titrating with thiosulphate in the usual manner. In the process of baking the persulphate would appear to be entirely destroyed. Loaves were made from several mixtures, but even when the persulphate was present to the extent of 1 to 500 of flour, no benzidine reaction could be obtained on treatment of the finished loaf.

ISSN:0003-2654    

DOI:10.1039/AN9123700090

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

92 ABSTRACTS OF CHEMICAL PAPERS ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. FOOD AND DRUGS ANALYSIS. Estimation of Bitter Principles in Wort and Beer. Neumann. (Woc~emch. Brau., 1912, 29, 31-36.)- Wiegmann (Allg. Brauer- u.. Hopfenxeit., 1911) has described a method for extracting the bitter resins from hopped worts and beer. The difficulty with the usual solvents of low boiling-point lies in the formation of emulsions which do not separate completely. Wiegrnann therefore recommends the use of petroleum spirit of sp. gr. 0.7350, so that the emulsion which tends to be formed may be destroyed by heating subsequently in a water-bath at 80" to 8 5 O C. ; 500 C.C. of the wort are shaken with 100 C.C. of petroleum spirit, and transferred to an Erlenmeyer flask of 1 litre capacity, which is placed in the water-bath.The flask is connected with a condenser, by means of a short piece of rubber tubing, in such a way that the con- tents of the flask can be shaken vigorously in the water-bath until the emulsion is destroyed. The liquid is then poured carefully into a separating funnel, the wort is removed, the petroleum spirit is washed, filtered, treated with alcohol, and the dissolved bitter principles are titrated with alcoholic potassium hydroxide. Some beers give trouble even under the above conditions, but emulsions can generally be prevented if the sample be first boiled with 1 to 2 per cent. of phosphoric acid (sp. gr. 1-12> for about fifteen minutes under a reflux condenser. The author describes a simpler method than that recommended by Wiegmann for overcoming the emulsion difficulty.Ether is used as the extracting solvent, and the difficulty is overcome by employing an unusually large proportion of ether, and extracting the beer in small portions at a time. Fifty or 100 C.C. of flat beer are shaken with five times their volume of ether in a long-shaped separating funnel, preferably in a shaking machine. After drawing off the extracted beer, a further quantity of 50 or 100 C.C. of the beer are treated with the same lot of ether, and so on until the whole of the sample has been exhausted. No difficulty in separating is experienced, even with dark beers. J. F. B. Estimation of Benzoic Acid in Margarine, Butter, and other Fats. W. Friese. (Pharm. Zentralhalle, 1911, 52, 1201-1203 ; through Chem. Zentralbl., 1912, I, 96.)-One hundred grms.of the sample are thoroughly mixed with 25 C.C. of 20 per cent. sodium carbonate solution, and heated on the water-bath until a milky fluid separates beneath the fat. The beaker is then cooled in an ice chest, and the layer of fat removed and washed repeatedly with ice water. The aqueous layer and washings, which will contain all the benzoic acid as sodium benzoate, are treated, without filtration and in the cold, with 40 C.C. of 10 per cent. barium chloride solution, which will precipitate barium salts of the saponified fat and barium carbonate. The liquid is filtered, and the filtrate freed from barium by means of sulphuric acid and again filtered. The new filtrate is twice extracted with ether in a, separating funnel, the united ethereal extracts washed with water and dried overFOOD AND DRUGS ANALYSIS 93 calcium chloride, the solvent evaporated by means of a current of air, and the residue dried in a desiccator and weighed.C. A. M. Estimation of Camphor. H. C. Fuller. (U.S. Department of Agriculture, Circular No. 77, Bureau Chem. ; through Anzer. J. Pharm., 1912, 84, 40-41.)-The author employs the camphoroxime method for determining camphor in its prepara- tions, and the following outline illustrates its application to spirit of camphor : Exactly 35 C.C. of a hydroxylamine solution (containing 20 grms. hydroxylamine hydrochloride, 30 C.C. water and 125 C.C. of aldehyde-free absolute alcohol) are added to a mixture of 25 C.C. of the sample with 2 grms. of sodium bicarbonate, and the whole gently boiled for two hours under a reflux condenser.On cooling, 6 C.C. of hydrochloric acid (sp. gr. 1.12) and 6 C.C. of water are added, the condenser and flask washed out, the liquid diluted to 500 c.c., and filtered. Fifty C.C. of the filtrate are neutralised with alkali to methyl-orange (mineral acid), when phenolphthaleln is added and the excess of hydroxylamine titrated with FG alkali. A blank experiment, using 35 C.C. hydroxylamine solution and 25 C.C. alcohol, is made, and the difference in the titrations noted. Each C.C. of & alkali= 0.01509 grm. camphor. A. R. T. Estimation of Cinnamein in Peru Balsam. F. Lehmann and A. Muller. (Arch. Pharm., 1912, 250, 1-5.)-The method of estimating cinnamein described in the German Pharmacopceia is shown to be inaccurate owing to no account being taken of the increase in volume in the ether used for the extraction.This may cause an error of more than 1 per cent. in the estimation. The following process based on those employed by Froinme and by Stocker is recommended as accurate and rapid. The use of so large a quantity of tragacanth as 3 grms. (Fromme) is unnecessary, provided that the bulk of the water be first drawn off, leaving only a small residue to be absorbed. Two and a half grms. of the Peru balsam are shaken with 5 C.C. of water in a stoppered 75 C.C. flask, after which 30 grms. of ether are added, and the shaking continued for one minute. An addition of 5 grrns. of sodium hydroxide solution is now made, and the flask once more shaken for one minute and allowed to stand for ten minutes.I t is next inverted, the stopper partially withdrawn, and the aqueous layer drawn off down to about 3 c.c., after which 0-5 grm. of gum tragacanth is introduced, and the whole thoroughly shaken and allowed to stand for three to five minutes. The bulk of the ethereal layer (25 to 28 grms.) is now decanted into a wide-mouthed tared flask, which is immediately covered and weighed. The ether is evaporated on the water-bath, and the viscous residue of cinnamein dried for thirty to forty-five minutes at 100" C., cooled in a desiccator, and weighed. C. A. M. Detection of Cocoanut Oil in Butter and Lard. E. Polenske. (Arbeit. Kaiserl. Gesund heitsamte, 191 1, 3 8, 403 - 4 14 .)-The results of a critical examination of the methods proposed by Ewers (cf.ANALYST, 1910, 35, 353) and Fendler (ibid., 1910, 35, 354) are recorded. Genuine butters of known origin were employed in the experiments, and it was found that the methods mentioned cannot be relied on for the purpose of detecting the presence of cocoanut oil in butter fat. As regards94 ABSTRACTS OF CHEMICAL PAPERS Ewers’ method, butter fats having Reichert-Meissl values of from 29.9 to 31-2 yielded “difference values ” varying from 8.5 to 8-8 ; other samples, also having high Reichert- Meissl values, gave “difference values” of from 13 to 14, and these samples could be adulterated with 10 per cent. of cocoanut oil and still show “ difference values ’’ above the minimum limit of 9 fixed by Ewers. Fendler’s alcohol method (Zoc.cit.), when applied to genuine butters, yielded values varying from 28.7 to 81, whilst several butters gave from 9 to 11 C.C. of ethyl esters when examined by the ester method (Zoc. cit.). The Polenske value of the butters used in the above investigation were normal, and showed that this method is trustworthy; further evidence is adduced that the method is also reliable for the detection of cocoanut in lard. w. P. s. Fruit Juice Statistics for the Year 1911. A. Behre and K. Frerichs. (Zeitsch. Untersuch. Nahr. Genussm., 1911, 22, 733-736.)-Juices prepared from fermented fruit and exemined during the year yielded the following result8 : Straw- berry juice (5 samples) : alcohol, 0-44-2039 ; total solids, 3.49-4-78 ; acidity (as malic acid), 1.19-1-75 ; ash, 0-37-0.52.Raspberry juice ( 5 samples) : alcohol, 0.30-25% ; total solids, 7-06-9.61 ; acidity, 3-35-4-32 ; ash, 0.75-0.89. Currant j z k e (6 samples) : alcohol, 0-2.32 ; total solids, 5-73-6.74 ; acidity, 2-76-3.79; ash, 0*61-0*74. Pine-apple juice (4 samples) : alcohol, 0-0.53 ; total solids, 7.08-16.28 ; acidity (as citric acid) 0*60-1.28 ; ash, 0.35-0.67 ; invert sugar, 4.03-7.15 ; sucrose, 0-8.33. As regards the pine-apple juices, two of the sampIes were unfermented, and two slightly fermented ; the sucrose was completely inverted in the fermented samples. Two of the samples of currant juice yielded a positive reaction with Windisch’s test for cherry juice (cf, ANALYST, 1902, 27, 10); the coloration obtained was very slight, and the authors are unable to The above figures express grms.per 100 C.C. explain why the juice should contain hydrocyanic acid. w. P. s. Occurrence of Arsenic in Gelatin. 0. Kopke. (Arbeit. KaiserZ. Gesund- heitsamte, 1911, 38, 290-293.)--Of twelve samples of commercial gelatin examined by the author, no less than eight contained appreciable quantities of arsenic, the amounts varying from 0.05 rngrm. to 0.3 mgrm. per 10 grms. of the sample. The remaining four samples also contained arsenic, but the quantity was a mere trace. With regard to the origin of the arsenic, i t is pointed out that gelatin is prepared from hide and leather residues, the hides having been treated with lime and arsenical preparations, or from bones which have been extracted with impure mineral acids, etc. ; gelatin is also bleached with sulphurous acid, which is not always free from arsenic.w. P. s. Estimation of Gum in Syrups. A. C. Chawvin. (Ann. FaZsq., 1912, 5, 27-30.)-The usual method for the estimation of gum by precipitation with an alcoholic solution of lead acetate gives satisfactory results when certain precautions are observed. The author, however, prefers to precipitate the gum-acid by means of alcoholic hydrochloric acid. For instance: 5 C.C. of the solution are treated with 5 C.C. of hydrochloric acid, 5 C.C. of water, and 85 C.C. of 100 per cent. alcohol. It isFOOD AND DRUGS ANALYSIS 95 particularly important to add the reagents, both acid and alcohol, in a rapid stream of drops, but not as a continuous jet, and to keep up a rotatory movement of the gum solution whilst these are being added, The precipitate is filtered off, washed with 95 per cent.alcohol, dried and weighed, and the dry weight is increased by the percentage of ash and moisture in the variety of gum present, or alternatively by 16.1 per cent., representing average values of 2.4 per cent. for ash and 13.7 per cent. for moisture. The quantity of sugar present does not interfere with the results provided the precipitate has been thoroughly washed, but pure aqueous solutions of gum nearly always give more accurate results. Ten per cent. solutions of gum generally show slightly low results, whilst 20 per cent. solutions show values ranging from 19 to 21 per cent. J. F. B. Mutarotation of Honey. L. Rosenthaler. (Zeeitsch. Unterszbch. Nahr. Genzcssm., 1911, 22, 644-647.)--In order to determine the mutarotation of honey, 10 grrns.of the sample were dissolved in water, with the addition of alumina cream, made up to 100 c.c., and the solution filtered. The solution of the filtrate was then observed in a 200 mm. tube fifteen minutes after the water has been added. Another similar solution was prepared and treated with ammonia gas, the solution being observed at the end of thirty minutes. The difference between the first rotation, a, and the second, e, gives the mutarotation, m. For purposes of comparison, the latter 100 rn value may be calculated into the specific mutarotation-[m] = --, where Z is the I X C length of the tube and c the total solids of the honey solution. As the result of the examication of forty-one samples of honey, it was found that for normal honey the value m varied from 0.12 to 2.60, and that of [m] from 0.71 to 15-47.All the samples of honey which had become solid (grained) exhibited a high mutarotation, and, assuming that dextrose exists in two modifications, it appears that crystallisation is accompanied by a change of the less optically active modification into the more strongly rotatory modification. Invert sugar showed a specific mutarotation of 15.08, whilst the value in the case of two samples of starch syrup observed was 1.20 and 2.60, respectively. w. P. s. Estimation of Mustard Oils in Oil-Cakes and Mustard Flours. C. Brioux. (Ann. chim. anal., 1912, 17, 3-9.)-1n the author's experience the method of oxidising the essential oils with bromine and estimating the sulphuric acid produced is unreliable, the oxidation being only partial. The method based upon the decom- position of the essential oil by means of silver nitrate is more accurate, but the modification prescribed by the French Codex gives results about 10 per cent.too low. The following method of estimation is suggested: A mixture of 25 grms. of the finely ground oil-cake with 500 C.C. of water at about 37' C., and 2 grms. of sodium fluoride (previously dissolved in a little water) as an antiseptic, is kept for an hour in a water-bath at 37Oto 4OoC., the closed flask being shaken from time to time. In the case of certain foreign oil-cakes or of mustard flour, it is necessary to continue the maceration for three or four hours, or longer.After the enzymic action is complete, 20 to 25 C.C. of 95 per cent. alcohol are added, the contents of the flask96 ABSTRACTS OF CHEMICAL PAPERS distilled, and 150 C.C. of the distillate collected in a 250 C.C. flask containing 10 C.C. of concentrated ammonia solution. From 25 to 50 C.C. of & silver nitrate solution (according to the probable quantity of essential oil) are now added, and the flask heated for an hour beneath a reflux condenser, on a water-bath at 80" to 85' C., after which the liquid is made up to 250 C.C. and filtered. An aliquot portion (125 c.c.) of the filtrate is acidified with 10 C.C. of strong nitric acid, and treated with 10 C.C. of a 10 per cent. solution of iron ammonium sulphate, and the residual silver titrated with & ammonium thiocyanate solution.I n the case of colza or rape-seed oil-cakes the essential oil consists of crotonyl thiocyanate, whilst in the case of black mustard-seed oil-cake or flour, the oil is allyl isothiocyanate. The distillate from Indian colza oil-cakes usually contains a mixture of the two essential oils, since the oil-cakes are composed of mixtures in varying proportions of Brassica glauca, B. diclzotoma, B. ramosa and B. campestris with more or less B.jmcea (Sarepta mustard). Of these seeds only B. juncea yields allyl thiocyanate, whilst the others produce crotonyl thiocyanate. Indian colza oil-cakes containing too great a pro- portion of the seed of B. juncea or B. nigra are thus dangerous to cattle. Apart from a microscopical examination, it is possible to make an approximate estimation of the amount of these seeds from the relative proportions of the two essential oils. For this purpose the liquid, after completion of enzymic action, is distilled without the addition of alcohol, and the distillate collected in the absence of ammonia.Crotonyl thiocyanate (sp. gr. 0.984) will then collect upon the surface of the liquid, whilst allyl thiocyanate (sp. gr. 1.028) will form a layer at the bottom. As a rule the temperatures employed in modern oil-factories are too low to inhibit completely the activity of the myrosin. French colza and rape-seed may yield from 0.150 to 0.250 per cent. of crotonyl thiocyanate, and their oil-cakes generally give from 0.20 to 0.35 per cent, In Danubian colza oil-cakes the author has obtained by the method described from 0.50 to 0.70 per cent.of essential oil, whilst Indian colza oil-cakes have yielded from 0.640 to 0.858 per cent. calculated as crotonyl thiocyanate, but generally containing a certain proportion of allyl thiocyanate. C. A. M. Wine Statistics for the Year 1909- 191 0. A. Gunther. (Arbeit. Kaiserl. Gesundheitsamte, 1911, 39, 1-470.)-The results of the analyses of 802 samples of wine and 3,991 samples of must are recorded in the present report, the samples being classified for the different vine-growing districts. As in previous reports (cf. ANALYST, 1910, 35, 64, 526), the proceedings of the Official Commission on Wine Statistics are given. The variation in acidity of wine during storage has been further investigated, and experiments have been carried out regarding fermentation in the presence of ammonium compounds, the alteration undergone by wine solids during drying, the effect of neutralising or diminishing the acidity of wine by the addition of calcium carbonate, etc.With respect to the use of nicotine solutions as insecticides on vines, one investigator states that nicotine cannot be detected, either chemically or by the taste, in wine made from vines so treated, whilst another reports that nicotine could be tasted distinctly in wine made two weeks after the vines had been sprayed. The iodometric method described by Zeissl and Fanto (cf. ANALYST, 1909, 34, 399) for the estimation of glycerol in wine was found toFOOD AND DRUGS ANALYSIS 97 No. 1. yield trustworthy results. The presence of large quantities of sugar was without influence on the results except that mannose, when present, caused the figures to be too high. The ordinary lime method gave low results when applied to wines containing much sugar, only about 75 per cent. of the glycerol present being obtain ed . w. P. s. Limits. Minimum. I Maximum. No. 2 . No. 3. Composition of Guadaloupe Rum. J. Sanarens. (Ann. Falsq., 1911, 4, 642-644.)-The following results were obtained on the analysis of three samples of rum imported into France from Guadaloupe. The samples were taken as the spirit was discharged from the vessel, and the figures express parts per 100,000 of absolute alcohol. The maximum and minimum limits fixed by the French authorities for this class of spirit are also given : Total acids ... 148.99 Aldehydes . . . . . . 13.92 Esters . . . ... 47-14 Higher alcohols . . . 100.67 Furfural ... ... 1.17 140.93 20.13 67-78 92.28 1 *84 Volatile acids ... 71-25 1 67 90 77.79 14.58 64 82 120.09 0.64 80 15 50 120 1 42-78 1 - I - 150 30 140 200 3 w. P. s.

ISSN:0003-2654    

DOI:10.1039/AN9123700092

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

FOOD AND DRUGS ANALYSIS 97 BACTERIOLOGICAL, PHYSIOLOGICAL, ETC. Amyloclastic Secretory Capacities of the Embryo and Aleurone Layer of Hordeum. F. Stoward. (Ann. Bot., 1911, 25, 799-841, 1147-1204.)-A North African and a brewing Chilian barley were used in this investigation, the seeds being sterilised either with 10 per cent. copper sulphate solution or absolute alcohol prior to dissection. The medium which served as the basis of the culture experiments, and to which were added as required gelatin, sugars, agar, asparagine, etc., had the following composition per 100 C.C. of solution : Calcium sulphate 0.1 grm., potassium chloride 0.25 grm., magnesium sulphate 0.25 grm. , potassium dihydrogen phosphate 0.025 grm., and 2 drops of The enzyme activity is expressed in terms of mgrms.of copper per twenty objects per hour, “objects” being either inner endosperms, embryos, or aleurone layers, and the copper being that obtained from Fehling’s solution as the result of the action of reducing sugar formed from starch during the experiment. The copper reductions were for the most part carried out by Bertrand’s method (Ezdl. SOC. Chim., 1906, 35, 1285). A large number of digestions under varying conditions are described, designed ferric chloride to the litre.98 ABSTRACTS OF CHEMICAL PAPERS to throw light on the amylase secretory capacity of the barleycorn, the following being some of* the principal conclusions deduced : Both embryos and aleurone layers possess an amylo and a cytoclastic secretory function. These secretory functions are completely arrested and annulled when these objects are subjected to the action of anaesthetic reagents such as chloroform and nitrobenzene.This result, in the case of the aleurone layer, is regarded as evidence that this tissue possesses vitality. The inner endosperm, under varying conditions of experiment described, possesses the capacity of augmenting its amylase content, not however by secretion, a, function that the amyliferous cells do not possess. I n contradistinction to the secretory capacities of the embryo and aleurone layer, the augmentation of amylase is not arrested or diminished by the acticin of chloroform or nitrobenxene. This latter fact is taken to signify that (1) the inner endosperm represents a mass of non-living tissue, and that (2) its behaviour under the conditions described is such as a dead mass of enzyme-containing tissue would exhibit.Isolated endosperms possess the capacity of inducing complete auto-digestion and auto-depletion of their storage contents. Isolated inner endosperms are incapable of inducing auto-digestive and auto-depletive processes in any way comparable with those observed in the case of endosperms. The augmentation of amylase by the endosperm in presence of anaesthetics such as chloroform and nitrobenxene undergoes marked reduction, being reduced to the same order of magnitude as that of the inner endosperm. The augmentation of amylase by the inner endosperm is unaffected--i.e., it is of the same order of magnitude as that of non-anaesthetised inner endosperms. Anaesthetised endosperms, unlike non-anaesthetised endosperms, are capable of inducing complete auto-depletion of their reserve storage materials.Endospermic depletion, as it occurs in the intact seed, is principally conditioned by the action of enzymes secreted by the aleurone layer and embryo ; in the isolated endosperm, by the aleurone layer secretions; and in both cases the principal r61e is due to the aleurone layer; the amyloclastic enzyme pre-existent in the inner endosperm and that which it generates is adjunctive. The amyloclastic enzymes secreted by the embryo and aleurone layer are iden- tical, and are distinct from that existent in and generated by the inner endosperm. Sucrose inhibits the secretion of amylase by the embryo, dextrose diminishes it, but invert sugar has apparently no influence on the phenomenon.The suggestion that the amylase which arises as secretions of the embryo and aleurone layer may activate that of the inner endosperm is not supported by experimental evidence. H. F. E. H. Estimation of Colloids in Arable Soils. J. Konig, J. Hasenbaumer, and C. Hassler. (Landw. Vers-Stat., 1911, 75, 377-441.)-The mineral and organic colloids are important factors of the fertility of a soil since they absorb and retain the soluble nutrient salts useful to the plant. A measure of the richness of a soil in colloidal constituents may be obtained by estimations of the absorption-capacity ofBACTERIOLOGICAL, PHYSIOLOGICAL, ETC. 99 the soil towards dyestuffs or mineral salts. A suitable dyestuff is methyl violet in aqueous solution at 1, 2 or 3 grms.per litre, according to the capacity of the soil. Five grms. of the soil are shaken with 100 C.C. of the dyestuff solution, and after thorough clarification the amount of dyestuff removed by the soil is estimated colori- metrically. The absorption of the dyestuff depends chiefly on the colloidal clay constituents of the soil. For estimating the adsorption capacity of the soil towards mineral salts, a gG solution of dipotassium phosphate is used, the base and acid of which are absorbed by the soil in proportions approximately the same as they exist i n the salt. The potash, however, is retained mainly by the clay colloids in a state of true adsorption which is readily reversed by treatments which flocculate the colloids ; the phosphoric acid, on the other hand, is taken up mostly by the lime and ferric oxide of the soil in chemical combination forming insoluble phosphates.If the soil be dried with the phosphate solution and then washed with a definite amount of water, the quantity of potash absorbed is lower and the quantity of phosphoric acid is higher than when the soil is not dried with the salt solution. For the estimation of absorbed or adsorbed ions in soils, whether natural or previously treated with nutrient solu- tions as above, the authors liberate these ions by flocculation or oxidation of the colloids. Two methods for effecting this liberation have already been described-viz., by steaming and by oxidation with hydrogen peroxide. A new method is now recommended which consists in treating the soil with a powerful continuous electric current.The apparatus used is a dialysing cylinder, open at the top and closed by parchment at the bottom,in which are placed 200 grms. of soil stirred to a sludge with water, and with a layer of about 4 cm. of water on the top. This is suspended in the container, and the water outside the dialyser is filled up to the same level as inside. Platinum electrodes are arranged so that the anode is at the bottom of the outer vessel and the cathode is immersed in the dialysing cylinder. A tension of 220 volts is employed, the resistance being regulated so that the current does not exceed 3 amperes. The liquid in the inner and outer vessels is renewed when the temperature rises to 50" C. The liquid in the cathode chamber becomes alkaline, whilst that in the anode chamber becomes acid and contains humus matters ; the permanganate values of the two liquids afford an indication of the organic matters, and the liquids are then mixed in aliquot proportions for the estimation o total solids, mineral matter, potash, lime, and phosphoric acid.Exhaustive treatment by the electrical method generally affords results very much higher than those obtained by steaming or oxidation. The authors therefore prefer to extract the soil twice by steeping with water for ten to twelve hours and then to subject it only once to the electrical treatment until the temperature rises to 55" C. The washings and the electrical dialysates are then united for analysis. By this treatment the results for potash coincide fairly closely with those afforded by the stearning and oxidation methods, and for phosphoric acid the single electrical and the steaming methods agree fairly well.Relations between the absorption capacity for dyestuffs or for dipotassium phosphate and the crop-yield exist in the c a ~ e of the upper and lower portions of the same soil but do not hold for different kinds of soil ; nevertheless, the dyestuff test can be recommended as a simple and rapid preliminary test for the general character of the soils. Comparisons between the amount of nutrient ionsI00 ABSTRACTS OF CHEMICAL PAPERS assimilated by the crop and the results found by the three analytical methods mentioned showed good concordance only for the potash. As regards the phosphoric acid, the steaming and single electrical treatments generally gave two to five times the amount assimilated by the crop ; the oxidation method only showed relationships in the case of upper and lower portions of the same soil, since the phosphoric acid results by this method depend on the quantity of humus colloids prosent.For the lime, the results for all three methods were far in excess of the amount required by the plant. J. F. B. Modification of Riegler’s Method for the Estimation of Urea in Urine. T. Ekecranyz and K. A. Sodermann. (Zeitsch. physiol. Chem., 1912’76, 171-176.) -Reigler’s method, which depends upon the fact that urea is decomposed into equal volumes of carbon dioxide and nitrogen when heated with nitric acid containing a small quantity of nitrous acid, may be combined with Dumas’ method for the estimation of nitrogen in organic substances.The combined method consists in measuring the volume of nitrogen liberated from a given volume of urine when the latter is heated with a, modified form of Millon’s reagent. One C.C. of the urine is placed in a test-tube which is closed with a cork through which pass an inlet tube, a delivery tube, and the stem of a tapped funnel. The delivery tube is connected with the lower end of a nitrometer filled with 50 per cent. potassium hydroxide solution, and a current of carbon dioxide free from air is then passed through the test-tube until the complete absorption of the bubbles in the nitrometer shows that the apparatus is filled with carbon dioxide. The level of the potassium hydroxide solu- tion in the nitrometer is then adjusted, 2 C.C. of the modified Millon’s reagent are admitted to the test-tube from the tapped funnel, and the contents of the latter are boiled for a, few minutes, the gases evolved being driven over into the nitrometer by means of a current of carbon dioxide. When nitrogen ceases to collect, its volume is read off, corrected to normal temperature and pressure, and calculated into urea. w. P. s.

ISSN:0003-2654    

DOI:10.1039/AN9123700097

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

I00 ABSTRACTS OF CHEMICAL PAPERS ORGANIC ANALYSIS. Estimation and Elimination of Sulphur Compounds in Commercial Bonzol. (J. SOC. Chem. Ind., 1912, 31, 10-l2.)-The principal sulphur compounds occurring in benzol are carbon disulphide and thiophene. So large an amount as 20 per cent. of the former compound may be present without imparting its peculiar odour to the benzol. The Csrius method of determining sulphur in organic compounds is here inapplicable, owing to the small content of sulphur: Garrett and Lomax’s method (ANALYST, 1906, 31, 52) for sulphur in petroleum gives low results in the ca8e of benzol, owing to the volatility of the latter. Irwin’s method, generally accepted for the estimation of sulphur in benzol, is an adaptation of the well-known “Gas Referee’s Test.” The author finds that a factor approximating to 1.8 will give a fairly good result, as shown by the following figures : J.G. Ellerton. It gives concordant but low results, as Irwin pointed out.ORGANIC ANALYSIS 101 Factor. Grains per Gallon. 486 ... 277 ... 1.75 486 ... 283 ... 1-72 486 ... 270 I . . 1-80 564 ... 307 ... 1-83 Sulpliur Present. Sulphiir Found. Grains per Gallon. For the estimation of carbon. diszdphide only, Macagno's modification of Nickel's method is used. The benzol is agitated with alcohol potash, and the potassium xanthate so formed titrated with & copper sulphate solution, using potassium ferro- cyanide as indicator. An approximation may be made from the density of the benzol by subtracting from it the value 0.885, and dividing by 0.00346.Thiophene is determined by Denigds' method, a strong solution of mercuric sulphate being added to the benzol dissolved in methyl alcohol, and the compound formed dried at 115" C., and weighed. Carbon disulphide masks the reaction and interferes slightly, but the method is useful for all ordinary benzols containing 1 per cent, or less of carbon disulphide. Owing to its different boiling-point, carbon disulphide is easily removed from benzol. This is not the case with thiophene, however, which is usually washed out by means of concentrated sulphuric acid, a method entailing the loss of about 8 to 12 per cent. of benzol. The best results for removal of thiophene were obtained by washing the benzol with fuming sulphuric acid of sp. gr. 1-87, giving three washes of 6 per cent.of the acid in all. By this treatment the thiophene was reduced from 1.22 per cent. to 0.22 per cent. Various oxidising agents such as ozone, lead oxide, and hydrogen peroxide were tried as a means of eliminating thiophene, but, while ozone gave the best results, with a low loss of benzol, the action was too slight to have any practical value. The following amounts of sulphur were found in com- mercial 90 per cent. benzols : From Durham tar, 250 grs. ; Yorkshire tar, 240 grs. ; Lancashire, 49 grs. ; Staffordshire, 504 grs. ; and crude benzol (coke-oven) 64.4 grs. sulphur per gallon. A. R. T. Detection of Carbon Bisulphide in Oils. E. Milliau. (Ann. chim. anal., 1912, 17, 1-3.)--Twenty-five grms. of the oil are saponified with 10 C.C. of a concen- trated aqueous solution of potassium hydroxide in the cold, the soap dissolved in about 150 C.C.of warm water, a pinch of sodium bicarbonate added, and the solution decomposed with 20 C.C. of pure hydrochloric acid. The vapours emitted are tested with lead acetate paper, which will be darkened in the case of extracted olive oil containing 0-05 to 0.1 per cent. of carbon bisulphide. No coloration is given by cotton-seed, kapok, colza, or expressed olive oils, or by extracted oils which have previously been heated for an hour at 130" C,. Another test is to distil 50 grms. of the oil with 10 C.C. of pure amyl alcohol, and to collect the first 5 C.C. of the distillate. A mixture of I. part by volume of kapok oil and 4parts of the distillate together with a few cgrms.of powdered sulphur are now heated in a sealed tube in boiling water. I n the case of expressed olive or other oil no coloration is produced even after three hours' heating, whereas an extracted olive oil containing 0.1 per cent. of carbon bisulphide gives a distinct red coloration. It is preferable to. neutralise the102 ABSTRACTS OF CHEMICAL PAPERS kapok oil with sodium hydroxide before using it in the test. Cotton-seed oil may be used in place of kapok oil as a reagent, but gives a somewhat weaker coloration. The reducing agents in kapok and cotton-seed oils are not volatile with steam. No coloration is given by extracted oils after being heated for an hour at 130" C. C . A. XI. Estimation of Cinnamic Acid by .Means of Bromine in Aqueous Solution.A. W. K. de Jong. (Bev. trav. chirn. Pays-Bas, 1911, 30, 223-224; through Chcm. Xentralbl., 1912, I., 162-163.)-When bromine is allowed to act for a long time on cinnamic acid in aqueous solution, more than 2 atoms of bromine are absorbed additively ; this, however, may be avoided by operating in the following manner : The substance to be analysed, for instance, a mixture of cinnamic and benzoic acids, is dissolved in sodium hydroxide and reprecipitated with hydrochloric acid, bromine in the form of a +> aqueous solution is run in, and the absorption of bromine is con- sidered to be at an end when the liquid assumes a yellow colour which is not discharged within five minutes. Potassium iodide is then added, and the iodine liberated is titreted in the usual manner.J. F. B. Dimethylglyoxime as a Reagent for Ferrous Salts. P. Slawik. (Chem. Zeit., 1912, 36, 54.)-DimethyIglyoxime, which is frequently employed for the estimation of nickel, gives an intense red coloration with ferrous compounds, and may be used for their detection. One drop of a solution of a ferrous salt is mixed with a little tartaric acid and 1 C.C. of an alcoholic solution of dimethylglyoxime, and an excess of ammonia is then added. The red coloration is very intense, and the reaction exceeds in delicacy all the other tssts for ferrous iron, but the colour gradually disappears as the ferrous compound becomes oxidised by the action of the air into the ferric state. This defect makes the test not very satisfactory for the detection of small traces of ferrous salts, since complete oxidation may occur owing to the rise of temperature occasioned by the addition of the ammonia. Ferric salts give the coloration on the addition of a, reducing agent-q., stannous chloride or metallic zinc.J. F. B. Estimation of Fat by Extraction with Cold Solvents. C. Grimme. (Chem. Rev, Fett- u. Harx-Ind., 1912, 19, 1-5.)--Estimations made under parallel conditions with different non-inflammable solvents by the method of cold extraction were compared with those made by the ordinary method of extraction with ether. The following results, which are typical of those obtained, represent the average percentage of fat extracted from a sample of cotton-seed meal in five estimations : Ether. Chloroform' Tetrachloride. ethylene. ethylene.ethylene. ethane. ethane. 7.45 8.58 7-43 8-13 7.46 7.79 7-71 9.62 Carbon Dichlor- Trichlor- Perchlor- Tetrachlor- Pentachlor- Only in the case of carbon tetrachloride and trichlorethylene did the fat agree in amount, colour, and analytical values with that extracted with ether, the other solvents extracting substances other than fat. Further experiments showed that the followingORGANIC ANALYSIS 103 modification of Neumann’s method (ANALYST, 1911, 36, 542) was the most rapid and accurate : Ten grms. of the finely powdered sample are shaken for forty-five minutes with 100 C.C. of carbon tetrachloride, or for thirty minutes with the same quantity of trichlorethylene in a stoppered 150 C.C. flask, care being taken that the shaking is done in the direction of the vertical axis of the flask.After standing for thirty minutes, the contents are filtered (the funnel being covered with a clock glass), 50 C.C. of the filtrate evaporated, and the residue dried for an hour at 1 0 5 O C., air being blown across it from time to time. The weight of fat multiplied by 20 may be taken as sufficiently accurate up to 10 per cent. Between 10 and 15 per cent. an addition of 0.2 per cent., and between 15 and 20 per cent. an addition of 0.4 per cent. should be made, these corrections being based upon the average specific gravity of fat (0.93). In comparative estimations of the amount of fat in thirty-eight samples of different seed cakes and fish meal, the results thus obtained with carbon tetra- chlorideand trichlorethylene agreed within - 0.16 to + 0.17 with those given by the usual method of extraction with ether.The percentages of fat extracted by the two first solvents were the same, with or without preliminary drying of the material (Cf. Gowing Scopes, ANALYST, 1910, 35, 238). C. A. M. Estimation of Mercury in Oxyphenyldimercuric Acetate and Mercuri- salicylic Acid. R. Brieger. (Arch. Pharm., 1912,250, 62-71.)-The mercury in oxyphenyldimercuric acetate may be quantitatively estimated by dissolving the salt in hot 30 per cent. acetic acid, adding an excess of standard iodine solution, and titrating the excess of iodine after twenty-four hours : C,H,OH (HgOOCH,), + 41 = Hg(OOCCH& + HgI, + CH,OHI,. The concentration of the acid has an influence upon the velocity of the reaction, and by nearly neutralising the solution with potassium hydroxide the amount of mercury found was 99-2 per cent.of the theoretical amount after one hour’s action. For estimating the mercury in mercuri-salicylic acid the following method is described : Half a grm. of the sample is dissolved in 30 C.C. of hot Fc potassium hydroxide solution, and the liquid diluted to 100 c.c., and treated with a few drops of 0-nitrophenol solution, after which 30 C.C. of & hydrochloric acid are added, and the excess of acid titrated with TG alkali. One C.C. of the alkali consumed by the sample corresponds to 0-0138 grm. of salicylic acid, and the difference between 100 and the calculated percentage of salicylic acid, multiplied by the factor 0.5952, gives the percentage of mercury, The result thus obtained should correspond fairly closely with the value obtained as follows : A solution of 0.3 grm.of the sample in 10 C.C. of & potassium hydroxide is mixed with 25 C.C. of water and 5 C.C. of 30 per cent. acetic acid, and treated 25 C.C. of +$ iodine solution, the excess of which is titrated with thiosulphate after fifteen hours. One C.C. of the iodine solution corresponds to 0.0100 grm. of mercury, or to about 0.3 per cent. in the sample, under the prescribed method of estimation. C. A. M. Valuation of Dynamite Glycerol. F. Hofwimmer. (Chew. Zeit., 1912,36, 41.)-On account of the possible presence of polyglycerols the only satisfactory104 ABSTRACTS OF CHEMICAL PAPERS method for testing the value of a glycerol is a determination of the nitroglycerine obtained by nitration.The author'e apparatus consists of a burette divided into 0.05 c.c,, sealed At the top into a thin-walled cylindrical water-jacketed nitrating vessel, with a mark one-third from the bottom, and terminating upwards in a neck. Above it is clamped a weighed stoppered tap pipette, with two marks, to deliver 10 grms. of glycerol. This is dropped slowly into about 60 grms. of nitrating acid (45 per cent. nitric acid + 55 per cent. sulphuric acid) previously adjusted to the mark in the nitrating vessel and cooled to 15" C., while a brisk current of dried air is passed up the burette. A thermometer in the nitrating vessel is unnecessary if the cooling water is at 15-16' C., and the flow rapid. All the glycerol having been run in, the air is allowed to pass for one minute longer.After fifteen minutes' standing the acid is run out to the zero mark on the burette, the volume of nitroglycerine read off, and calculated to 10 grms. of glycerol, after weighing back the glycerol pipette. For comparison, a standard is made by similarly nitrating 10 grms. of chemically pure glycerol. The determination must always be carried out under the same con- ditions; the quantity of glycerol taken must be between 9.9 and 10.1 grms. The determination can be finished in an hour. 0. E. M. Alteration of Nitrocellulose and Nitrocellulose Powders by Heat. R. Fric. (Comptes rend., 1912, 154, 31.)-The effect of heat on nitrocelluloses and nitrocellulose powders is to lower the viscosity of their acetone solutions, measured by the number of seconds required for 25 C.C.of solution to flow through a tube of 2 mm. bore 20 cm. long. Thus a collodion cotton declined from 69-3 to 57.7, after heating at 80" C. for seven hours twenty-five minutes; a guncotton from 210 to 99 under similar treatment ; a smokeless blank from 36 to 21 after five hours at 110" C . ; and a sporting powder from 94.8 to 33.3 after twelve hours at 110" C. 0. E. M. Physical and Chemical Properties of the Petroleums of the San Joaquin Valley of California. I. C. Allen and W. A. Jacobs. (American Bureau of Mines, 1911, Bull. 19, pp. 60).-This pamphlet deals with the collection of samples and their physical and chemical examination. An. electrically-heated still, suitable for difficult distillations, is figured and described, and full details are given of its mode of operation and devices employed in connection with it.Owing to trouble with frothing samples, a closed form of flash tester could not be used, and an open Pensky-Martens cup screened from air-currents was employed. Viscosity was determined in an Engler viscosimeter at 20" C. and calorific value in a Berthelot combustion bomb (Dinsmore-Atwater model). To prevent bumping a '' boiling stone " of porous porcelain or pumice weighing about 0.5 grm. is found to be most useful, even with heavy oils that boil at 325' C. under a pressure of 20 mm. A large number of samples are tabulated with the analyses of their fractions. H. F. E. H. Colorimetric Estimation of Salicylic Acid and Copper. F. Schott. (Zeitsch. Untenuch. Nahcr.Genwssm., 1911, 22, 727-728.)-Jorisssn's reaction, as described by Shermann and Gross (ANALYST, 1911, 36, 463), may be used for the colorimetric estimation of salicyclic acid and, conversely, for the estimation of smallORGANIC ANALYSIS 105 quantities of copper. I n the case of salicylic acid, a definite quantity of the solution is placed in a test-tube, and in a set of exactly similar tubes are placed quantities of 0, 0.2, 0-4, 0.6, 0.8, 1.0, etc., C.C. of a salicylic acid solution which contains 100 mgrms. of the acid per litre. To each tube are now added 2 C.C. of Fehling’s copper solution diluted previously with nine times its volume of water, 5 drops of a 2 per cent. potassium nitrite solution, and 5 drops of 10 per cent. acetic acid. After thevolumes of the mixtures in the test-tubes have been diluted to a volume of 5 c.c., the tubes are heated in a boiling water-bath for forty-five minutes, cooled, and the coloration yielded by the solution under examination cornpared with those given by the quantities of salicylic acid in the other test-tubes.Salicylic acid may be estimated directly in milk by means of this method. Twenty-five C.C. of the milk are treated with 10 C.C. of Fehling’s copper solution and the mixture is nearly neutralised with 7 sodium hydroxide solution ; after filtration, 15 C.C. of the filtrate are mixed with 5 drops of 10 per cent. potassium nitrite solution and the same quantity of 10 per cent. acetic acid. The coloration obtained on heating the mixture is then compared with standards prepared with milk containing known quantities of salicyclic acid.The colour of the milk serum remains unaltered in the absence of salicylic acid, but the reaction is readily obtained when the quantity of the latter amounts to 10 rngrm. or more per litre. For the estimation of copper, comparison solutions containing 0, 0.1, 0.2, 0.4, etc., C.C. of a, copper sulphate solution containing 0,3927 grin. of the crystallised salt per litre (equivalent to 100 mgrms. of copper) are employed. To each tube is added 0.3 C.C. of a 0.5 per cent. salicylic acid solution (in dilute alcohol) together with the above-mentioned qualities of nitrite and acetic acid, and the estimation is then carried out as described in the case of salicylic acid. Sucrose, dextrose, lactose, and invert sugar do not interfere with the reaction, but free mineral acids, tartaric acid, citric acid, and more than mere traces of iron should not be present in the solution under examination.The coloration is yielded by as little as 0.01 mgrm. of copper. w. P. s. Use of the Ileagent “ Tetramethyl Base.” R. J. Carney. (J. Amer. Chem., SOC., 1912, 34, 32-35).-Tetramethyldiaminodi-phenylmethane (CH3),N2(C,H,)2CH2 in acetic acid solution was used by Trillat (Compt. rend., 1903, 136, 1205-1207) for the detection of traces of lead and manganese. The author, who finds many advantages in substituting citric acid for acetic, dissolves 2.5 grms. of the base in 10 C.C. of water containing 10 grms. of citric acid, and dilutes to 500 C.C. The base itself is prepared as follows: A mixture of 30 grms. of dimethylaniline, 10 grms. of formaldehyde, 200 C.C. of water, and 10 C.C. of sulphuric acid is warmed on the water-bath for one hour. After cooling, the mixture is made alkaline with excess of caustic soda, tind the excess of dimethylaniline driven off with steam. The brownish product is cooled, filtered, and washed with water, and then recrystallised once. from alcohol, The base is recommended as a new test for gold; with very dilute solutions, the reagent gives a beautiful purple colour, soon changing to blue, and then fading ; the blue colour reappears on warming. The reaction is not interfered with by platinum, palladium, or other106 ABSTRACTS OF CHEMICAL PAPERS elements, and is more distinct than “purple of Cassius.” Free mineral acid must be absent, so solutions should be neutralised and made slightly acid with acetic or citric acids. The test shows 0.01 mgrm. per 50 C.C. in a solution containing nothing but gold. H. F. E. H.

ISSN:0003-2654    

DOI:10.1039/AN9123700100

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

106 ABSTRACTS OF CHEMICAL PAPERS INORGANIC ANALYSIS. Rapid Estimation of Carbon Monoxide. L. A. Levy. (J. Xoc. Chem. Ind., 1911, 30, 1437-1439.)-The author has devised a colorimetric method for this estimation, accurate to about 0.3 per cent., which is regarded as sufficiently near for technical purposes. The method is based on that of Gautier (Comptes rend., 1898,126, 793), in which carbon monoxide is selectively oxidised to carbon dioxide by means of heated iodine pentoxide. The author then aspirates the oxidised gas through a known volume of standard baryta solution coloured with phenolphthalein. The solution becomes colourless when it is completely neutralised by the carbon dioxide, the colour change thus corresponding to a fixed volume of carbon monoxide, which can be measured, and the percentage of the latter estimated.Certain precautions are necessary in carrying out the process. Unsaturated hydrocarbons are oxidised by iodine pentoxide, and must therefore be removed before the oxidation. The inhibitory action of traces of ethylene on the oxidation of carbon monoxide by the iodine pentoxide at 60" to 100" C. is not noticeable if the oxidation be effected at 170" C. The gas is bubbled through a strong solution of bromine in potassium bromide at a rate not greater than 2 litres per hour, and bromine vapour is then removed by potassium hydroxide solution (1 in 2), which also serves to remove any carbon dioxide in the original gas. After this treatment the gas is dried by passing over phosphorus pentoxide in a tube 4 inches long and 1 inch in diameter.The gas is oxidised in a U-tube containing iodine pentoxide mixed with ignited asbestos to render the column pervious to the passage of gas, and the liberated iodine is caught in a connected U-tube full of copper turnings, with which the iodine combines. This oxidation apparatus is contained in an air-oven maintained at 160" to 180' C. The oxidised gas now passes to the baryta absorption coil, a special form of which is employed in order to obtain complete absorption of carbon dioxide. The baryta solution is of such strength that it is exactly neutralised by the passage of 20 C.C. of carbon dioxide measured at 60" F. and 30 inches pressure. A three-way tap is interposed between the oxidation-tube and the baryta decolorisation vessel, so that the gas may be by-passed until the test is commenced; 100 C.C.of gas completely displaced r;he residual gas in the apparatus. If the volume of water flowing out of the aspirator =V, which is the volume of gas passing, then V C.C. contain 20 C.C. of carbon dioxide, and the percentage is T, which can be directly read off on a specially graduated aspirator vessel. The results agree to within about 0.3 per cent. with analysis made with accurate forms of gas-analysis apparatus. The results with weaker barytasolution, in the case of gases containing only 1 to 2 per cent. of carbon dioxide, are not quite so good. Better results are obtained by using strong baryta solution with large volumes of gas, and titrating back the excess of alkali with oxalic 2000INORGANlC ANALYSIS 107 acid.from lime-kilns, etc. Westminster. A. R. T. This method is useful in the analysis of fumes from stoves, mine air, and air The apparatus is made in portable form by A. Wright and CO., Rapid Estimation of Manganese in Ferro-Tungsten. P. Slawik. (Chem. Zeit., 1912, 36, 106.)-A mixture of 1 grm. of the finely-divided sample with 10 grms. of sodium peroxide is heated in a porcelain crucible for two or three minutes at a dull red heat, cooled, and extracted with water, acidulated cautiously with hydrochloric acid, boiled fifteen to twenty minutes with a large excess of the acid, boiled UP with a slight excess of zinc oxide, and titrated with permanganate. As a check, the same sample was decomposed with sodium hydroxide and potassium nitrate in a nickel crucible, the melt dissolved in water, the manganese precipitated with sodium peroxide, filtered off, ignited, dissolved in hydrochloric acid, diluted, and, after addition of zinc oxide in slight excess, titrated hot with permanganate.Results showed a maximum error for the first method of 0.02 per cent. on an alloy containing 0.47 per cent. manganese as determined by the second. 0. E. M. Separation of Phosphomolybdates from Silieomolybdates. P. Melikoff. (Comptes rend., 1911, 153, 1478.)-Ammonium molybdate precipitates silicic acid as well as phosphoric acid. A mixture of equal volumes of 30 per cent. hydrogen peroxide and 8 per cent. ammonium molybdate in nitric mid dissolves out the phosphomolylo’date from the precipitate, leaving the silicomolybdate.The reaction may be followed under the microscope. 0. E. M. Geoehemieal Interpretation of Water Analysis. C. Palmer. (U.S.A. Geological Survey, 1911, Bull. 479, pp. 31)-The interpretation of the chemical character of a water from the results of analysis is necessarily uncertain and unsatis- factory if it is based merely on the amounts of the radicles determined ; a form of statement which discloses their true relations and proportions is required, and this the author, following Stabler, calls their proportional reaction capacity. The reaction capacities of the radicles of dissolved salts are the quotients obtained by dividing the weight of each radicle by its equivalent combining weight. The “reaction coefficient ” is the chemical reacting power of a unit weight of a radicle, or the ratio of the reaction capacity of 1 part of that radicle to the reaction capacity of 8 parts of oxygen.Thus, calcium has an atomic weight of 40, an equivalent weight of 20, a reaction coefficient of & or 0.05. The product of the (‘ reaction coeficient ” and the amount of a radicle is called the reacting value ” of that amount of the radicle, and is really equal to “ mgrm. equivalents of hydrogen.” When water analyses are so expressed, many operations such as the calculation of the amounts of remedial agents required to produce desired changes are much facilitated. In a particular water the reacting values of the alkali metals was 0.264, and that of the sulphates and chlorides 0.188. The excess of alkalinity (0.076) multiplied by 53 (the combining weight of sodium carbonate) is equal to 4.02, which represents the parts of sodium carbonate per million of water. I t is advisable that the reacting value of a water be expressed independently of its particular concentration so as to facilitate comparison108 ABSTRACTS OF CHEMICAL PAPERS of different waters which vary in their total saline content.This is done by stating the reacting value of each radicle as a percentage of the concentration value, and SO obtaining a ‘‘ character formula,” which not only shows the radicles found, but clearly distinguishes slight differences in the proportions of these radicles present in any waters that are to be compared. The following five properties of a water may be distinguished : (I) Primary salinity due to salts of alkalis and strong acids ; (2) secondary salinity due to salts of alkaline earths and strong acids ; (3) acidity or excess of strong acid if any; (4) permanent alkalinity due to alkali metals ; and (5) temporary alkalinity due to alkaline earths. Carbonic acid is not regarded as capable of producing acidity, and silica and alumina are classed separately as colloids. An extensive series of analyses of American river waters is given, and the results discussed in relation to the geology of the river basins. H. F. E. H.

ISSN:0003-2654    

DOI:10.1039/AN9123700106

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

108 ABSTRACTS OF CHEMICAL PAPERS APPARATUS, ETC. Thermo-Regulators. W. R. Bousfield. (Chew. News, 1912, 105, 13-14.)- The figure shows an air-thermostat, capable of being used for water by slight changes of A $13 fi E detail. This form was designed to regulate the heat of an electric radiator, worked direct from the main, carrying an alternating current at 240 volts. A, B, are the upper and lower surfaces of a mercury column in a barometer-tube, part of the column being in series with the radiator and the main current, which passes in and out of the mercury by platinum wires 1 mm. thick, sealed in the glass walls of the tube. The current enters at C, a point low enough to be always immersed in mercury. The circuit is closed by contact with the platinum wire D at B. The connected bulb E is filled with hydrogen through F, a cock, C, serving to regulate the amount of mercury for the desired temperature, and enabling E to be thoroughly washed out with hydrogen.Overheating of the thermostat expands the gas, and causes the mercury surface B to be forced away from the platinum wire, cutting off the current. The reverse process takes place when the temperature falls below the mean. The mean pressure in E must be so chosen that the mercury in A normally occupies half the bulb. The mercury in H allows of the filling of A in case of overheating, and prevents air-bubbles passing the bend at the bottom and spoiling the vacuum in A. If the mean pressure in E is about equal to atmospheric pressure, as it should be, then the tube will be of the length of the ordinary barometer- tube, and possible leakage of hydrogen through defective taps is avoided.The use of hydrogen in E is necessary, since it forms no compound with mercury, and the sparking at B does not result in oxidation nor deterioration of the surface of the mercury. A modified form of a Lowry gas regulator is also described, which is unaffected by gas and atmospheric pressure variations, and is sensitive to 0.01" c. A. R. T.GOVERNMENT REPORT 109 Filtration with Alundum Plates. R. C. Benner and W. H. Ross. (J. Amer. Chern. SOC., 1912, 34, 51.)-Filtration of large volumes of liquids containing very fine precipitates by means of asbestos fibre and the Witte plate is sometimes inconvenient, and it is claimed that there is an advantage in the use of “alundum” (fused aluminium oxide) discs made by the Norton Company of Worcester, Mass., which are to be had in several grades with pores of different sizes. They fit into a glass funnel by means of an ordinary flat rubber band, and their use makes possible the stirring of the precipitate while on the plate. H. F. E. H.

ISSN:0003-2654    

DOI:10.1039/AN9123700108

出版商:RSC    

年代:1912

数据来源: RSC