摘要:

THE ANALYST. MARCH, 1903. PROCEEDINGS OF THE SOCIETY OF PUBLIC ANALYSTS. THE Annual General Meeting of the Society was held on Wednesday afternoon, February 4, in the Chemical Society’s Rooms, Burlington House. The President, Dr. J. Augustus Voelcker, M.A., B.Sc., occupied the chair. The minutes of the previous annual meeting, held on January 22, 1902, were read and confirmed. Mr. Julian L. Baker and Dr. Philip Schidrowitz were appointed to act as scrutineers of the ballot-papers for the election of officers and Council for 1903. The Hon. Treasurer (Mr. E. W. Voelcker, A.R.S.M.) presented his report for the year 1902. Mr. B. KITTO, in moving the adoption of the report, proposed a vote of thanks to the Hon. Treasurer for his services during the past year. Mr. W. T. BURGESS seconded, and the motion was carried unanimously.The HON. TREASURER having responded, proposed a vote of thanks to the Mr. HEHNER seconded the proposition, which was unanimously carried. Dr. LEWKOWITSCH acknowledged the vote of thanks. On the proposition of Mr. JOHN WHITE, seconded by Mr. A. E. EKINS, a vote of thanks was unanimously passed to the President and Council of the Chemical Society for their kindness in allowing the Society the use of their rooms for meeting purposes during the past year. Auditors, Mr. John Hughes and Dr. Lewkowitsch. The PRESIDENT (Dr. J. Augustus Voelcker) delivered his annual address. Mr. ALLEN proposed a vote of thanks to the President for his address, coupled Mr. HARVEY seconded, and the proposition was carried unanimously. The PRESIDENT having responded, Mr.HEHNER proposed, and Mr. JENKINS seconded, a vote of thanks to the The vote of thanks was unanimously passed, and was acknowledged by Mr. The scrutineers having reported to the President the result of their examina- with a request that he would allow it to be printed in the Society’s proceedings. Hon. Secretaries, Mr. E. J. Bevan and Mr. Alfred C. Chapman. Chapman.58 THE ANALYST. tion of the ballot-papers, the President announced the unanimous election for the ensuing year of officers and Council as follows : President : Thomas Fairley. Past Presidents (Limited by the constitution of the Society to ten in number) : M. A. Adams, A. H. Allen, A. Dupre, Bernard Dyer, W. W. Fisher, Otto Hehner, Alfred Hill, J. Muter, Thos. Stevenson, J.Augustus Voelcker. Vice-Presidents : Bertram Blount, Sidney Harvey, F. Wallis Stoddart. Hon. Treasurer: E. W. Voelcker. Hon. Secretaries : E. J. Bevan and A. C. Chapman. Other Members of CoumiZ: L. Archbutt, H. Ballantyne, L. Briant, W. T. Burgess, J. Hendrick, J. Lewkowitsch, F. J. Lloyd, W. F. Lowe, Raymond Ross, P. Schid- rowitz, D. A. Sutherland, W. Collingwood Williams. Dr. Voelcker, having introduced the newly-elected President, vacated the chair, which was then taken by Mr. Fairley. Mr. FAIRLEY, having expressed his acknowledgment, the proceedings terminated. THE ordinary monthly meeting of the Society was held on Wednesday evening, February 4, in the Chemical Society’s Rooms, Burlington House. The President, Mr. Thomas Fairley, occupied the chair.The minutes of the previous ordinary meeting were read and confirmed. Certificates of proposal for election to membership in favour of Messrs. F. W. F. Arnaud, A. E. Bell, B. R. Coysh, and E. M. Hawkins were read for the second time; and certificates in favour of Messrs. Frederic Guy Stirling Baker, B.A. (Oxon), Marryatt’s Lodge, Snaresbrook, assistant to Mr. Alfred C. Chapman, F.I.C. ; Mon- tague Kelway Bamber, Colombo, Consulting Chemist to the Government of Ceylon ; Frank Crossley, Analytical Chemist, Duchy Bank, Seedley Road, Pendleton, Manchester ; George H. Gemmell, F.I.C., Public Analyst for the Burghs of Linlith- gow and Kirkwall, 4, Lindsay Place, Edinburgh; Adolf Jaffe, Broad Oak, Oak Avenue, Bradford, chief assistant to Mr. F. W. Richardson, F.I.C. ; Arthur Garfield Levy, B.Sc. (London), A.I.C., assistant to Mr. Bertram Blount, F.I.C. ; Frederick Grevile Ruddock, F.I. C., Consulting and Analytical Chemist, Egypt Street Chambers, Warrington ; and Thomas Tyrer, F.I.C., Stirling Chemical Works, Stratford, E., were read for the first time. Messrs. A. H. Bennett and W. Partridge were elected members of the Society. The following papers were read : (‘ The Determination of Glycerine in Crude Glycerines,” by J. Lewkowitsch, Ph.D. ; and ( ( Note on the Determination of Casein Precipitated by Rennet,” by H. Droop Richmond.

ISSN:0003-2654    

DOI:10.1039/AN9032800057

出版商:RSC    

年代:1903

数据来源: RSC

摘要:

THE ANALYST. 59 THE PRESIDENT’S ANNUAL ADDRESS. (Delivered at the Annual Meeting, February 4, 1903.) MY allotted term of two years of office as President of this Society expires to-day, and, like my predecessors, I go now to join the ranks of those whom you honour as your Past-Presidents. One in my position at such a time as this naturally reviews the past, and asks himself the question whether, under his guidance for the time being, the Society has prospered, or the reverse, and whether its outlook for the future be brighter than when he assumed, by the choice of his colleagues, oftice as President. When I undertook this post, I pointed out that my selection marked in some ways a new departure, inasmuch as I was not in the strict sense a Public Analyst- or, rather, not one holding this position under the Saleof Food and Drugs Act.The broadening of the Society’s basis and of the scope of its work, indicated in this and other directions, has not, I venture to think, been at all detrimental to the general welfare, and I may hope that those who are official Public Analysts in no way feel that their interests have been neglected. Had the Society merely to exercise the functions of a close corporation, confining its membership to official analysts, and existing primarily for the purpose of safeguarding the position, emoluments, etc., of its members, then it could be little more than a ‘‘ trade union,” or “mutual pro- tection society.’’ Its larger function, “ the cultivation of the study of analytical chemistry,” could not be adequately performed by such a confined body.The development, accordingly, has come about gradually and naturally, and to the benefit, I think, alike of the members and of the different branches of analytical chemistry which they severally represent. So I hope that the Society has not suffered through the experiment initiated two years ago, and, perhaps, after a fitting interval, the plan may be repeated. Reviewing the past two years, it may fairly be claimed that the Society has not merely maintained its ground, but that it has distinctly improved its position, and that it has taken a better place in scientific circles and in the estimation of the public. Considering it as the only Society in this country which concerns itself directly with analytical chemistry, as the only one that issues a journal devoted to analytical chemistry, and that discusses questions of importance to analysts at large, the Society occupies a unique position and serves a special purpose.Alike by the papers read before it, and by the pages of the ANALYST, the Society has continued to show itself an active and useful organization, and a contributor to the progress of chemical science. Turning to the composition of the Society, the membership has been increased during the past year by the addition of seventeen fresh names, while nine have been lost either through death or removal. Among our losses have to be recorded, with deep regret, the deaths of two of our honorary members, Sir Frederick Abel and Dr. J. H. Gladstone. The eminence of each of these men was so widely recognised that no further reference to it need here be made, and though their particular spheres of work did not bring them very closely into touch with us, yet we felt it an60 THE ANALYST.honour to have them on our list of distinguished associates. At our last annual dinner, on February 12, 1902, Dr. Gladstone was present, and testified to the kindly feeling and interest he had for us. To those whose association with Dr. Gladstone was of the intimate and long-standing nature that my own was, it will ever be remembered how, with a singular disinterestedness, he devoted himself alike to scientific research and to the welfare of his fellow-men. By those who knew him well he will be thought of, not alone for his contributions to science, but for his works of philanthropy, and for his endeavours for the spread of education and of religious thought and influence.In the list of Council there has been, happily, no change to record, but in our membership we have lost, firstly, Dr. C. M. Aikman, Public Analyst for Ayr and Lanerk and other Scotch burghs, and a well-known writer on chemico-agricultural matters, and then Professor Ivison Rilacadam, of Edinburgh, whose tragic death was SO prominently before us at the time. In the matter of finance we stand in a satisfactory position. Owing to increased expenditure over extra printing necessitated by special inquiries, such as that of “Butter Standards ” and the ‘ I Arsenic Question,” the working expenses were much heavier last year. A large number of circulars had to be sent out in order to obtain the views of members on particular points connected with these inquiries, and to keep them posted up in what was doing with regard to these matters. Such work, it seems to the Council, is very desirable and necessary, and the expense fully justified.Notwith- standing this, the year closes with a satisfactory surplus of income over expenditure, amounting to nearly &50. The publication of the ANALYST, again, has cost rather more than before, but here, too, it is felt that this is money well spent. On the whole, in our present treasurer’s hands the income is a slightly increasing one year by year, and there has been no need to entrench on the Society’s funded capital, but, on the other hand, there will be a further sum of nearly 3200 available for investment. The ANALYST continues worthily to uphold its character, and its circulation outside our own members shows steady increase.The work of the Editor, Dr. Sykes, with his staff of abstractors, has borne good fruit in making the journal acceptable and a useful medium for reference on analytical methods and the examination of special substances, while the time and care which the editorial committee bestow on the revision of the various abstracts submitted to them has resulted in the selection of such as seem to possess intrinsic merit. At the same time, it has been abundantly brought home to the Editorial Committee that there is a useful field open to them in more closely examining some of the methods or processes put before them from time to time, and in ascertaining how far the various suggestions may be practically useful.It is intended that such inquiries be prosecuted by different members of the Committee, and the results be communicated in the form of papers to the Society. Many a process put forward tentatively by its author may be found, on fuller investi- gation, to be impracticable, while others that have a sound basis cannot fail to be strengthened, and to become better known by the fact that men of eminence in their respective domains have examined the same and submitted them to close criticism and wider application, It is much hoped that this branch of the Council’s work will be well taken up and form an important part of the Society’s operations. The number of resignations was six.THE ANALYST.61 The list of papers read during the past year before the Society at its different January 22.--“ Note on Reichard’s ‘ Silver ’ Method for the Determination of “ Note on a Sample of Coffee containing Starch.” ‘‘ Note on a Sample of Artificial Coffee Beans.” ‘‘ Note on Spurious Cream of Tartar.” March 5.-“ The Detection of Artificial Colouring Matters in Fresh and Sour meetings is as follows : Morphine in Opium.” By Philip Schidrowitz, Ph.D. By Cecil H. Cribb, B.Sc. By Cecil H. Cribb, B.Sc. By John White. Milk.” By M. Wynter Blyth, B.A., B.Sc. Oxidized Oils.” By J. Lewkowitsch, M.A., Ph.D. “ The Indirect Estimation of Alkalies in Water.” “ Note on a Simple Apparatus for Approximately Estimating the Colour of April 9.--“ Alkaline Waters from the Lower Greensand.” By W.W. Fisher, (‘ The Rapid Estimation of Boric Acid in Butter.” By H. Droop Richmond and L L The Detection and Estimation of Minute Quantities of Sulphuretted Hydrogen By W. J. Dibdin and R. G. Grimwood. “The Hexabromides of Glycerides and Fatty Acids.” By John Walker and ‘‘ Note on the Estimation of Mineral Oil in Rosin Oil.” By John Walker and May 7.--“ The Composition of Milk.” ‘‘ Fluorides as Butter Preservatives, with Observations on their Influence on L‘ Note on a Convenient Apparatus for the Chemical and Bacteriological By William Chattaway and F. M. By W. W. Fisher, M.A. Waters.” By W. T. Burgess. M.A. J. B. P. Harrison. in Coal Gas.” George Warburton. Charles D. Robertshaw. By H. Droop Richmond. Artificial Digestion.” Examination of the Atmosphere.” Wharton.By Otto Hehner and C. W. Hehner. ‘‘ Note on Some Drug Standards.” Juite 4.--“ Note on the Examination of Water from some Typhoid-polluted Wells.” By S. Rideal, D.Sc. (‘ The Estimation of Platinum in Alloys.” (‘ The Electrolytic Detection and Estimation of Arsenic.” By Otto Hehner. November Certain Reactions of the Alkaloids of Ipecacuanha.” By Alfred ‘‘ The Analysis of Preparations containing Opium.” By Alfred H. Allen and L b Note on the Estimation of Salicylic Acid.” By Sidney Harvey. L L Note on the Volatility of Aqueous Solutions of Acetic Acid.” December 3.--“ The Estimation of Available Phosphoric Acid in Manures.” L L The Estimation of Sulphur in Pig-iron.” By H. Wippell Gadd. By Percy A. E. Richards. By E. J. Bevan. The Action of Boiling Hydrochloric Acid on Arsenic Acid.” H.Allen and G. E. Scott-Smith. G. E. Scott-Smith, By William By Chat t away. W. F. Sutherst, Ph.D. By Clarence A. Seyler, B.Sc.62 THE ANALYST. “An Improvement in the Method of Separating Zinc from Nickel by means of (‘ Note on Pure and Commercial Civet.” Hydrogen-Sulphide.” By Ernest A. Lewis. By Herbert E. Burgess. The papers, as in recent years, show a wide range of subjects discussed, and embrace matters that travel much beyond the field of the official Public Analyst. Several interesting papers in connection with water analysis were brought forward, notably a contribution by Mr. W. W. Fisher on “Alkaline Waters from the Lower Greensand.” Mr. W. Chattaway, at the May meeting, introduced to notice a con- venient form of apparatus for making chemical and bacteriological examinations of the atmosphere, and, at the same meeting, Mr.H. D. Richmond made his annual communication on the composition of milk during 1901, 8s judged from the large number of samples passing through his hands. The analyses gave, on the average, for mornings’ milk a composition of 3-53 per cent. of fat and 12.46 per cent. of total solids, for evenings’ milk 3.91 per cent. of fat and 12.81 per cent. of total solids, or a general average, for mornings’ and evenings’ milk together, of 3.72 per cent. of fat with 12.63 per cent. of total solids. These figures showed a slight rise, principally in fat, above the figures of 1900. Another paper which attracted special attention was one read at the November meeting by Mr.A. H. Allen on ‘‘ Certain Reactions of the Alkaloids of Ipecacuanha.” This was of much importance, as bearing on a recent decision in a case where a cough mixture preparation had been reported on as containing opium, but which latter, it was subsequently found, was not present, though reactions in many ways very similar to those of opium had been produced by ipecacuanha. The Society held an additional meeting on May 21, to discuss the report of the Joint Committee appointed by the Society of Chemical Industry and the Society of Public Analysts to consider the question of the determination of minute quantities of arsenic. On this Committee leading members of the Society took an active part, and the report was presented by the Chairman, Mr.Hehner. The report was fully discussed, and an almost universal concurrence was given with the principle under- lying the Joint Committee’s method, and there could be but one opinion, viz., that the Committee had bestowed a very great deal of care and time upon their work, and that the results were of the highest importance, and should be adopted. The thanks of the Royal Commission on Arsenical Poisoning were expressed by Lord Kelvin, the Chairman, to the Society of Public Analysts for the evidence tendered on their behalf by the Society’s representatives, Mr. Hehner and Mr. Chapman. The Society desires to record its iudebtedness to those of its members who, along with Mr. Hehner, acted on this Committee, and shared in the laborious investigations with which the inquiry was concerned. In its relations to Government Departments and the head officials of these, the Society has every reason for congratulation.On several occasions the President and others have been accorded very courteous interviews with leading officials of the Local Government Board, when it has been felt necessary to make representa- tions to protect the position of certain members of the Society holding public appointments. To these representations every attention has been given, and, in theTHE ANALYST. 63 end, a favourable issue has been the result. Dr. Thorpe, head of the Government Laboratory, and now one of our honorary members, has on many occasions shown his goodwill to the Society, and has discussed with the officers, and with individual members, matters affecting Public Analysts in the discharge of their duties under the ,4cts under which they have been appointed.Of late the course of legislation has brought the Society into closer contact with the Board of Agriculture, and here again we have to acknowledge our indebtedness to Mr. Hanbury, the President, and to Sir Thomas Elliott, the Secretary, for the kind way in which the officers of the Society have been received in conference, and their representations been considered. The issue of regulations concerning the sale of butter, and the proposed legislation in regard to the sale of (‘ butterine,” have caused the Society much concern, and made representations on their part to the Board of Agriculture highly desirable. In setting out the views of members of the Society as a whole, the Council have gone to much trouble to canvass individual opinions, u p o ~ which their representations to the Board of Agriculture have been based, and to these expressions thus set out we are assured that much weight has been attached. The regulations ultimately adopted by the Board of Agriculture with respect to the proportion of water that should not be exceeded in butter were in perfect agreement with the views expressed by this Society.Similar steps were taken by the Council to canvass the opinion of members generally as to the more difficult question whether a legal standard, and, if so, what standard, should be fixed in regard to the genuineness of butter-fat. This, as was to be expected, produced the expression of somewhat divergent opinions, but the different views were collected and embodied in a meniorandum, which was put forward by the Society’s representatives when giving evidence before the Departmental Committee on the subject.Regulabions under this head have not been as yet drawn up by the Departmental Committee. Meanwhile, the matter of the sale of “ butterine ” was introduced by way of a Bill before Parliament, and once more the Society had to turn their close attention to this. The term “butterine ” did not commend itself at all to the Council, and there was a general consensus of opinion that some other term, such as (‘ wakered butter,” was distinctly preferable, as more rightly denominating the real nature of the article in respect of which legislation was being attempted.Other points in the proposed Bill called for representation on the Society’s behalf, and, in the end, the President and one of the Secretaries were accorded interviews, first with Sir Thomas Elliott, and then with the President of the Board of Agriculture. The matter remains, for the time, in abeyance; but the setting out of the action taken by the Society will show the members that not only is the Council alive to the interests which the members represent, but also that the Society’s relations to Government Departments are of a inost satisfactory nature, and that a ready hearing is accorded to the representations which they from time to time find it incumbent or desirable to make. The growing importance of the Society is yet again shown in a reference made to it during the year to adjudicate in a matter of difference of opinion which had arisen in India as the result of a prosecution which had been instituted in respect of the alleged adulteration of ghi in Calcutta. The documents in the case in question were submitted to the Society, who formed a special committee to deal with the64 THE ANALYST.matter, and, after the opinions of the members forming the committee had been individually given, a report was drawn up and the judgment transmitted to India. The decisions of the High Court in matters that have come up by way of appeal, and in which Public Analysts have been concerned, can hardly be said to have been, on the whole, so satisfactory. These affected the questions of ‘‘ Milk-blended Butter,” the amount of water to be allowed in margarine, and the quality of milk as yielded by a single cow.Under the first-named head there were four separate cases. In the first of these* it was held by the Judges that where ‘‘ Pearks’ Butter ” was the only butter sold at an establishment, a notice being exhibited on the wall to the effect that “Pearks’ Butter” was blended, and retained 20 to 24 per cent. of moisture, and the butter being put in a wrapper marked inside with a similar description, no cocviction could follow, even if the purchaser asked for I‘ shilling butter,” and if his attention was not specially called to the notice or label mentioned. The second caset referred to a sale of Pearks’ butter ” where the attention of the purchaser was not drawn to the fact of the material containing excessive water, the purchaser asking for and expecting butter.The conviction was here affirmed, and it was further decided that the fact of the defendants being a limited company would not prevent an action from lying. I n the third case,: the exhibiting of a printed notice in the shop and the wrapping of the purchase in paper with similar notifica- tion was held to be adequate, though the purchaser had asked for butter. I n the fourth case,§ action was taken against “ Pearks’ butter ” on the ground of its being This the Judges also dismissed, stating that the substance sold was not margarine, but butter and milk. From these cases it is clear that the difficulties in the way of securing a con- viction for the sale of “ Pearks’ butter,” even when “ butter ” is asked for, are very great, and it is high time that legislation should be introduced to deal specially with an article of this kind. butterine ” (as too closely resembling “ butter ”) have been already given, and it is to be hoped that c c watered butter,” or some other term exactly describing its nature, may be applied to 6‘ Pearks’ butter ’’ and similar compounds. A more satisfactory outcome was a High Court decision in the case of margarine containing 21 per cent.of water, the court holding that this was not margarine, but margarine and water. /I I t is clear that if 21 per cent. of water-or 10 to 12 per cent. more than margarine generally contains-can be allowed, there is no reason why 40 or even 50 per cent. of water should not be allowed, i f the material can be made to hold it.The last High Court decision was one of much importance, inasmuch as it ruled that though milk was sold exactly as it came from the cow, yet, if that fluid was, by reason of the cow being milked at widely different intervals (an abnormal margarine the fat of which contained more than 10 per cent. of butter-fat.” Our objections to the use of the term * Pearks, Gunston and Tee, Ltd., v. Hou hton. j- Pearks, Gunston and Tce, Ltd., u. War%. See ANAI,YST, May, 1902, p. 164. $ Hayes v. Rule and Law. 5 Bayley v. Pearks, Gunston and Tee, Ltd. I1 Joseph Burton and Sons, Ltd., v. Mattinson. IT Sinithies v. Bridge. See ASALYST, March, 1902, p. 110. Ibid., p. 165. Ibid., p. 167. See AN ~LYST, May, 1902, p. 169. Ibid., p. 171.THE ANALYST. 65 condition of things being thereby introduced), deficient in the constituents proper to genuine milk, it could not be considered as being “of the nature, quality, etc., demanded by the purchaser.” A matter of considerable importance to analysts was brought up in a paper read by one of the members of the Society, Mr.Bertram Blount, at the British Associa- tion, and since reprinted at some length in the ANALYST.” It had reference to the proposed standardization of methods of chemical analysis, Mr. Blount urged, and, as it seems to me, very properly, the objections to stereotyped methods, and pointed out how opposed it was to scientific inquiry and analytical research. The ANALYST has from the beginning of this year passed into other hands, in one sense.The Society has taken the publishing of its journal into its own hands, and has appointed Messrs. Simpkin, Marshall, Hamilton, Kent and Co., Ltd., their trade agents for its issue. These new arrangements, it is expected, will prove more satisfactory than those that have hitherto ruled. As regards the position of Public Analysts, this is undoubtedly becoming more and more important. We notice with much satisfaction the disposition on the part of public bodies and of Government Departments to insist on fitting qualifications for the men who are to fill the responsible position of Public Analyst, and we acknow- ledge gratefully the action taken, not once, but often, by the Institute of Chemistry in calling the attention of the Local Government Board and of local authorities to appointments advertised or made, in which the proper qualifications have not been sought, or, again, where local authorities have attempted to terminate, without proper justification, the tenure of an existing appointment by a qualified man. Such action cannot but have good effect in arousing local bodies to a due sense of their responsibilities and of their duty to their accredited officials. On the other hand, it increases, and very properly, the obligation resting upon the Society and on its members to set before them a high standard both of efficiency and of conduct, and the furthering of the endeavour to raise by these and other means the standard of the profession.The widening of the Society’s scope naturally again raises the question which has before been discussed-whether the present name of the Society is not too exclusive to represent its general character and aims, and whether this might not be with advantage altered so as to give expression to this wider view of its work. There is much to be said, pro and con, when the alteration of the name of a Society is con- cerned, and I do not think that I can usefully enter into this discussion now. But the matter is one that will probably early engage the attention of the new Council. And now, with my sincere expressions of obligation to the members, and to the Council in particnlar, for the support which they have accorded to me, and for the indulgence with which they have treated me, I resign my office to my successor. In Mr. Fairley you have one of the oldest and best-known Public Analysts in the country, and you have one whose ability, not in this line alone, but in the general field of chemical science, has long been recognised. I n your choice of Mr. Fairley as my successor you are returning to the line of Public Analyst Presidents, and you are giving the country the alternation with the town which it is well to preserve SO * AXALYST, November, 1902, p. 315. To turn now to the future.66 THE ANALYST. far as possible. In Mr. Fairley’s hands I feel that your interests and those of the Society will be secure, and, for myself, I would but say further what pleasure it has been to me to preside over this Society, how gladly I shall continue my interest in it, and how sincerely I appreciate the honour you have done me and the kindness you have shown me during my term of office.

ISSN:0003-2654    

DOI:10.1039/AN9032800059

出版商:RSC    

年代:1903

数据来源: RSC

摘要:

66 THE ANALYST. THE ESTIMATION OF AVAILABLE PHOSPHORIC ACID I N MANURES. BY W. F. SUTHERST, Ph.D., A.I.C. (Read at the Meeting, Decembe?. 3, 1902.) SINCE the introduction of the insoluble phosphatic manures, such as basic slag, a method for determining the amount of phosphoric acid which plants are capable of assimilating from them, and also the rate at which this takes place, has not yet been found to work with absolute precision owing to the very great difficulty in imitating such physiological processes in the laboratory. I t had been proved years ago that there were different states in which phosphates existed in the soil and in manures. One soil might contain as much phosphoric acid as another, but on the one soil a much poorer yield of the same kind of crop would be obtained than on the other.The earlier agricultural chemists, such as Liebig, Lawes, and Gilbert, found that when a soil was treated with weak acids, more especially organic acids, only a portion of the total phosphates was dissolved, and in some cases practically none; and from these observations, on comparing the soils giving up small quantities of phosphoric acid to such solvents with the crops grown on them, they found that the more plant food there was dissolved out of a soil by a weak solution of an organic acid the heavier would be the crop obtained from it. These were the first notices of the relation between the total plant food in a soil and the ariiount available. A number of standard solutions were suggested to represent the assimilating power of the plant, and in Germany One of these-viz., ammonium citrate-bas been generally adopted for both soil and manure analysis.In England one of the most rational solvents has been brought out by Dr. Dyer, based on the acidity of the plant roots themselves. The results of analyses of numerous varieties showed the average acidity to correspond to about a 1 per cent. citric acid solution ; and, from experiments carried out by Dr. Dyer on the Rothainsted soils, it was found that the quantities of potash, phosphoric acid, etc., dissolved out frorri the soil by this solution were about equal to those absorbed by the crops. This was the first suggested solvent which had been based on actual comparison of the root sap and also yield of crop. Such a solvent might possess the same degree of acidity as the root sap of most species of plants, but it would not have the same chemical composition, since the acidity is due to various acid salts of organic acids, in addition to other substances which might also have the power of dissolving substznces such as phosphate of lime out of the soil.To see how far these acid salts were representedTHE ANALYST. 67 by the action of citric acid, solutions of potassium binoxalate, bitartrate, and bimalate (whose strength was made equal to a 1 per cent. citric acid solution, except in the case of the bitartrate, which needed diluting down to enable it to dissolve), and various insoluble phosphatic manures-viz., basic slag, basic superphosphate, precipitated phosphate, and mineral phosphate-were mixed together, and at the end of forty-eight hours the amount of phosphoric acid dissolved was estimated. The method employed was as follows : One gramme of each manure was placed in a flask, and to this was added an amount of potassium binoxalate, bitartrate, and bimalate corresponding in degree of acidity to 1 gramme of citric acid, dissolved in 100 C.C.of distilled water (the bitartrate needed, however, 300 C.C. water for solution). After standing for forty-eight hours, with repeated agitation, half the liquid was filtered off, and in this the phosphoric acid was determined by the ammonium molybdate and magnesia mixture method. The following results were obtained : Manure used. I. POTASSIUM BINOXALATE AS SOLVENT. ( 3) (4) Precipitated Coprolite. * (2). r Basic (1).Basic Slag. Superphosphate. Phosphate. Per Cent, Per Cent. Per Cent. Per Cent. Containing P205 ... 13.31 13-01 39.67 37.03 (a) Amount P,O, dissolved 8.65 12-95 33.53 21-21 ( b ) P20, dissolved to total 64.98 99.53 90.54 53.71 11. POTASSIUM BITARTRATE AS SOLVENT. (1) (2) (3) (4) ... 8.32 12-97 33.60 14.80 ... 62-58 99.69 90.73 37.30 111. POTASSIVM BIMALATE AS SOLVENT. ( 4 ) 10.31 ... ... ... 5.06 9.85 ... ... ... 38-01 75.71 33.08 25.98 (3) 12.25 (1) ( 2 ) (4 ( b ) IV. CITRIC ACID AS SOLVENT. (1) (2) (3) (4) ... 8-61 11.37 32-69 7-88 ... 64.89 88.28 99.26 21.37 From the above results it will be seen that two of the solvents act in practically the same manner as the citric acid solution, but the other solvent-the potassium malate-appears to have a much weaker power than the others.The proposed standard, then, evidently represents to a great extent the acid bodies in the root sap, with regard to their power of dissolving the insoluble phosphatic fertilizers and the phosphates in the soil; but does the method of carrying out the estimation of the available phosphoric acid really represent the manner in which assimilation of plant food takes place? The sap in the rootlets, coming into contact with particles of soil and abstracting from these certain ingredients, must be subjected to a process of continual renewal, since there is a flow of liquid through the plant system from the roots to the leaves, brought about chiefly by evaporation of water * By coprolite the anthor evidently means mineral phosphate.ti8 THE ANALYST.from the leaves exposed to the sun’s heat. When a fertilizer, such as basic slag, is subjected to analysis for available phosphoric acid by either the citric acid or ammonium citrate method by allowing the solvent to remain in contact with a weighed portion of it, although the flask is rotated or agitated continually, the sample is only acted upon by the same solvent, whose strength must consequently be considerably reduced by the time a portion of the substance is dissolved. It occurred to me that by treating the same sample of a fertilizer with fresh quantities of citric acid solution this would approximatelycorrespond to the renewal of sap in the roots. The method used was as follows: Three grammes each of basic slag and mineral phosphate were placed in 500 C.C.flasks, and to these 300 C.C. 1 per cent. citric acid solution added, and after standing for forty-eight hours, with continual agitation, the amount of P,O, dissolved was estimated in 50 C.C. of the liquid. . The remaining liquid was then poured off, and the residue treated further with 300 C.C. citric acid solution, and the method repeated as before till very little more P,O, was dissolved. The results obtained were as follows : REPEATED ACTION OF 1 PER CENT. CITRIC ACID SOLUTION. Basic Slag. Per Cent. First extraction ... ... 8.612 Second extraction . . . ... 1.536 Third extraction ... ... 1.276 Fourth extraction . . . ... 1.021 Fifth extraction ... ... 0.764 Sixth extraction ... ... Seventh extraction . . . ... - - - Eighth extraction . . . ... Coprolite.Per Cent. 7.401 5.108 4.834 3.442 2.308 1.536 1.102 0.964 Since the basic slag contained 13.31 per cent. P,O, and the coprolite 37.03 per cent., it will be seen that from the former practically the whole amount is extracted after five extractions, while from the coprolite, though the analyses were not carried on so far, the greater part of the phosphoric acid was taken out in eight repeti- tions, and in a very regular manner. It appears from the above results that prac- tically the whole of the phosphoric acid in any manure is available for plant food, but that in some it is assimilable in a shorter time than others. Whether the usual method of testing the available plant food and the results obtained by it give any definite idea of the amount a plant is capable of absorbing or not, it seems from the experiments carried out that there is certainly a relation between the amount dissolved and the amount which is in an easy assimilable form, since the large proportion of phosphoric acid dissolved out of the basic slag by one treatment with citric acid as distinguished from that removed from coprolite in proportion to the total present easily accounts for the more rapid effect of basic slag on a crop than that of a ground mineral phosphate.DISCUSSION. Dr. DYER said that a solution of citric acid, of course, was necessarily not quite the same thing as the acid solution in root sap, which no doubt contained a mixture of acid salts. Still, he thought there was this to be said for a citric acid solution, &BTHE ANALYST.69 compared with some of these definite acid salts : that while each of these had one definite hydrogen equivalent-one definite acidity-citric acid had three, which possessed different degrees of intensity; so that when one was neutralized, the other two had less than two-thirds of the original acid intensity, while when two were neutralized there remained less than half of this, and possibly citric acid might thus afford a sort of good average acidity. Of course, however, the whole matter was largely arbitrary. Referring to the author’s results, he was surprised that citric acid (which in the case of basic slag appeared to have very much the same action as the solutions of acid salts employed) should be found to dissolve so much less phosphoric acid from the basic superphosphate of Mr.Hughes. R9r. Hughes had found that a citric acid solution, even of much less than 1 per cent. strength, dissolved a larger proportion of the phosphoric acid than had been dissolved in the author’s experiment in this particular case. I t struck him as being a point in favour of the use of citric acid, that, in the case of the ground coprolite, which was well known to be a slowly-acting and difficultly-available manure, the result shown in the paper was in direct accord with the slower action of the coprolite as compared with the known activity of the other manures mentioned. Ifr. JOHN HUGHES said that, with regard to the sample of coprolite referred to in the paper, he would like to mention that the materiai in question really consisted of Christmas Island phosphate, as he had learned from the author in the course of correspondence relating to some results which had been previously published in the Chemical News.He (Mr. Hughes) agreed with Dr. Dyer in preferring, as far as his experience had gone, the use of dilute citric acid solution as a solvent in determining the amount of available plant food in manures. There seemed something very appropriate in the use of a vegetable acid for such a purpose. As to what exact strength should be used in future, he ventured to think that considerable latitude might yet be taken before a standard was definitely fixed upon. When Dr. Dyer first suggested that a 1 per cent. solution should be regarded as the standard, that was naturally regarded as a very weak solution: but, aB he (Mr.Hughes) had already pointed out elsewhere, the figures given in Dr. Dyer’s original paper showed that, out of 103 samples of root sap, the acidity in the case of 27 samples was equivalent to more than 1 per cent. of citric acid, in 49 samples to between 0.5 per cent. and 1 per cent., while in 27 samples the acidity was equivalent to less than 0.5 per cent. of citric acid. On looking further into these figures, it appeared that nearly all the farm crops-wheat, barley, oats, perennial rye grass, Italian rye grass, white turnips, swedes, mangolds, smooth-stalked meadow grass, bheep’s fescue grass, foxtail grass, dogtail grass-showed an acidity corresponding on the average with about 0.5 per cent. of citric acid. He ventured to think, therefore, that, if solubility in a 1 per cent.solution were taken as a standard of availability, it must be regarded rather as too high than as too low. In analysing manure he would suggest that, if anything, the standard fixed should be one that was absolutely below the acidity of any known plants grown on the farm, and for this reason he had suggested a 0.1 per cent. solution, which represented an acidity below that of any of the 103 plants analysed by Dr. Dyer. He had found by experience in analysing the various manures mentioned that a solution of that strength gave a large amount70 THE ANALYST. of solubility, and yielded figures which he thought might fairly be taken as represent- ing the amount of available plant food in those manures. Mr. HEHNER desired to ask Dr.Dyer whether he still adhered to his original suggestion that a connection existed between the acidity of the root sap of plants and their power of absorbing plant food from the soil. Doubtless there were very good reasons for making the experiments which Mr. Hughes had just quoted, and upon which Dr. Dyer had bestowed such a large amount of labour ; but it seemed to him that, whereas those experiments had reference to the acidity of the juices within the plant, the solution of the plant food constituents must surely be effected mainly by conditions which lay outside of the functions of the plant proper. Mr. SEYLER thought it would be well that tbe question should be approached from the physical point of view of the extent to which the acid solvent was ionized.The degree of solution would depend to a greater extent upon the degree of ionization than upon the existence of a certain equivalent acidity taken towards an indicator. This had been found to be the case by Ostwald, who had determined the strength of several organic acids by their solvent action on calcium oxalate. It, would seem that the attention of agricultural chemists should be directed towards the selection of a solution having the same degree of ionization as the root sap, rather than one having the same absolute acidity. Dr. DYER said that when he first turned his attention to this subject, literature in reference to it had been accumulating for many years, and the general consensus of opinion among agriciiltural chemists was that, for purposes of soil analysis, if results were to be obtained which indicated in any kind of way the amount of available mineral plant food in soils, they should be obtained by the use of some weak acid solution.There were, however, differences of opinion as to the strength of acid that should be used. He had been led to think about investigating the acidity of the root sap by the experiments of Sachs, who many years ago had grown plants in soil in which polished slabs of marble were buried, with the result that the marble became etched wherever the roots went. .Sachs came to the conclusion that the juices of the roots exuded as they travelled along, and so dissolved and absorbed the carbonate of lime. As Mr. Hughes had very correctly remarked, in a large number of plants the acidity of the root sap was equivalent to less than 1 per cent.of citric acid, but in a good many it represented more, 1 per cent. being about the average. The use of a 1 per cent. citric acid solution having been already proposed-though not with reference to the same question-by a chemist of such authority as Stutzer, it had seemed undesirable that a fresh solution should be chosen as long as the one already proposed appeared to meet the case. This method of dealing with the matter, however, must be regarded as arbitrary, simply because it was never possible to work under soil conditions. The soil was really swamped with root sap solution-if it niight for the moment be so called-whereas the roots of plants could only apply their sap as they went along, assuming that to be really the mode of action.The. test, therefore, did not really imitate the actual processes of Nature ; but it was an attempt to place the investigation of the matter on some kind of rational basis, Mr. HEHSER said that, while the experiments of Sachs certainly indicated the exudation of acid by the roots, yet every living cell exuded carbonic acid, and theTHE ANALYST. 71 carbonic acid would fully account for the etching of a polished marble surface. If it were the case that the solution of plant food was due to the acidity of the root sap, other than free carbonic acid, it would seem that the amount of phosphoric acid absorbed by plants from a soil containing an excess of phosphates ought to vary according to their sap acidity, and he would like to ask whether, in Dr.Dyer’s experience, this was the case. Dr. DYER said that he could not speak precisely with regard to phosphoric acid, but with regard to potash an instance occurred to him which seemed to bear upon Mr. Hehner’s question. For some years past, in connection with some field experiments, he had been growing strawberries, among other plants, under different manurial conditions ; and, although strawberries demanded a great deal of potash, it had been found in these field experiments that they could be grown year after year without any manurial application of potash, on a soil which was naturally poor as regards that constituent, and on which almost all the other plants grown were grateful for it. He sometimes thought that this was possibly because the root sap of the strawberries (which was among the most acid of those he had examined) was SO vigorous that this plant could get potash where others could not.Other rosaceous plants examined agreed with tbe strawberry plant in showing a very high root sap acidity. The PRESIDENT (Dr. Voelcker) said that, while undoubtedly at the time of its introduction there were good grounds for believing that the action of a weak acid solution imitated what took place in Nature, botanists were now altogether opposed to the idea that actual excretion from the roots occurred, or that the amount of plant food taken up was dependent upon the acidity of the root sap. The question was one*that could not be satisfactorily settled without botanical as weli as chemical investigation.With regard to the methods suggested in the present paper, he certainly thought that if potash compounds were tried as solvents, compounds containing other bases ought to be tried also. Dr. Sutherst’s general conclusion seemed to be that potassium binoxalate and potassium bitartrate gave practically the same results as citric acid; but, from the figures given, it appeared that, although this was so in the case of basic slag, in the case of the so-called (‘ coprolite ” 21 per cent. of the total phosphoric acid was dissolved by citric acid, while as much as 53 per cent. was dissolved by potassium binoxalate, intermediate results being yielded by potassium bitartrate. In the case of the basic superphosphate the results showed the divergence to which attention had been called by Dr. Dyer, namely, that, while 88 per cent. of the phosphoric acid was dissolved by dilute citric acid, 99g per cent. was dissolved by potassium binoxalate. In the second part of the paper the author suggested that, inasmuch as the plant with its acid sap would take up certain materials, a regular change must go on in the character of the sap, and that, in dissolving the soil constituents, an attempt might be made to imitate that change by using the various solvents mentioned in successive doses. There seemed no doubt, however, that, if such treatment were carried far enough, complete solution could be effected in every case. He had heard with interest Mr. Hughes’s remark 8s to the nature of the (‘ coprolite ’) referred to, because he had only recently heard it contended that the material known a8 ‘‘ Christmas Island Phosphate ” would be more properly described as ‘‘ guano.”

ISSN:0003-2654    

DOI:10.1039/AN9032800066

出版商:RSC    

年代:1903

数据来源: RSC

摘要:

72 THE ANALYST. Alcohol per litre by volume Proof spirit per cent. ... Extract per litre . .. ... Acids (as acetic acid)::: ... Aldehydes'". . . ... ... Furfural:: . . . 9 . . ... Ethers (as ethyl acetate)':' Higher alcohols':' . . . , . . . Total secondary products':: --- --- ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. 454.1 79-57 nil 175-7 44.0 1-3 1377.8 334.7 1933.5 FOODS AND DRUGS ANALYSIS. (Oesterr. Chem. Zeit.,' 1903, vi., 2.)--Various authors have stated (cf, ANALYST, 1901, xxvi., 292) that, in using guaiacum as a test for heated milk, the wood tincture, and not the resin tincture, must be employed. Nevertheless, both wood and resin tincture yield the blue colour, but only after those tinctures have begun to suffer auto-oxidation by being exposed to light and air for at least eight or ten days.Guaiacum Test for Heated Milk. N. Wender. Fresh tinctures give no colour. F. H. L. 131.5 2.7 2.1 233.8 136.6 506.7 Report of the Special Analytical Commission on Brandy. (Lancet, November 29, 1902,15C)3-1518.)-A description is given of Cognac and other brandy- producing districts in the Charente, of the soils on which the vines grow, and of the different varieties of viries most suitable to the various districts ; the history of the attack of phylloxera from 1872 onwards, and the measures taken to combat it, and to restock the devastated vineyards, are entered into. Briefly, the wines which are poor in alcohol, sour and hitrsh to the taste, are distilled. The first runnings (t8te de brouillis) are collected apart, and returned to the next distillation ; the middle portion (caur de brouillis) is reserved for a second distillation ; and the tailings (queue de brouillis) are returned to the next distillation.The residue in the still is treated for the recovery of tartaric acid. The cceur de brouil?is is again distilled, and the first runnings (tdte d'eau de uie) are returned to fresh wine for a subsequent distillation. The middle fraction (cmur de destillation) is brandy, and the tailings (queue or secondes) are either returned to fresh wine, or are used for making ordinary brandy. The technical methods of producing brandy are described. Table I. gives the analyses of the various products of distillation. TABLE I. Analyses of Various Distillates in the E a r l y Stages of Brandy Production.--___ 120.0 nil nil 82.7 624 265.1 TGte de Cmur de 1 Queue de Brouillis. Brouillis. Brouillis. rGte d'Eax de Vie. 673-1 740.3 130.52 0.10 -* -- 49.3 24.7 3.0 568 *4 99.7 745.1 Cz$y Secondes. 679 -6 750.8 131.58 0.10 23.9 0-7 0.9 53.9 39.9 119.3 283.2 342.2 59 *96 0.10 123.2 0.7 4.5 279.8 67.1 475.3 * Expressed as gramines per 103 litres of absolute alcohol present.TABLE 11.- Analyses of Vintage Bmandies. - Alcohol per litre by weight ,, ,, hyvolume Proof spirit per cent. ... Extract per litre . . . . . . Acids as acetic acid" ... Furfural" ... Ethers as ethyl acetate" ... Higher alcohols" . . . . . . Aldehydes" . . . . . Total secondary products* -- ___I _ _ Bois. G. C. Bois. Bois 1 G. C. I Bois. P. C. Bord. 0. C. Bois. ' G. C. I P. C. 1858. 1875. 1 1888.1892: 1 1593. 1 1895. 1895. I 1900. 1900. 1901. I 1811. 1870. 450.9 446'4 527'7 522.9 112'411120'42,115*33 112'41 119.05 121'11 119*051 92-481 78'5( 3'20 2.201 1'50 0.80' 0'60 0'50 0'90 0.30 0.10 0*30/ 5.301 3'6( 218.3 165'2 110'6 82.0 ' 69'0 65'6 73.0 49'1 36.4 48-5 '300.2 265'2 23.7 21.2 17.9 10.8 9.7 7.4 7.1 4'4 47.4 37.2 178'3 144'6 125.2 152'4 124'7 86.7 151% 215'0 '193.3 '137.5 272.8 173.9 147.1 255.2 170.1 1162.1 164.9 135'6 163.7 1371.5 1342'2 - - _ c - _ _ _ _ I - ~ - 580.5 '610.8 580.5 563'2 602'6 615.0 602'6 450'9 376.7 658.1 '687.2 658.1 641'4 679.3 691-1 679.3 l527-7 '447.9 0.9 0.9 2.4 2'1 2'3 1.6 2.1 1 4.4 0'8 1.8 - _ ~ - 694'1 505.8 403.2 502.5 1371.9 1803.6 332.9 436'0 ,913.1 783'8 ---___ __ 513.2 89.59 G. C. = Grande Champagne. P. C. =Petite Champagne.Bord. = Borderies. 589'2 641'4 i632.4 '654.8 707.7 699.2 683.3 101'51 112.41 110.84 113'18 124'02 122.531119'74 TABLE 111.-Analyses of Typical Bradies h a the Market. I ONE STAR BRAKDY. 1 Landed 1902. 1 1 Bought in Market. . I-- .--_ __ ~ _ _ _ _ I Two STAR BRANDY. Landed 1902. i Bought in Market. - ___ I - - - ~ iiii,v;d ybl L h L >j ,, -;&: 9 , , by volume Proof spirit per cent. ... %xtract per litre , . . Acids as acetic acid" ... Aldehydes" . . . . . . Furfural* . . . . . . Ethers as ethyl acetate* Higher alcohols* ... Total secondary products* ... ... ... ... ... ... 66-5 12'3 2.5 98'4 122% 1 302'3 j I,""'? 498.1 87-29 5.90 65'0 10.0 2'4 97.1 80.3 254.8 AV.(; 1 4 i Z . n 4'77.6 ' -116-0 ~ 422-9 THREE STAR BRANDY. 1 SPECIAL BRANDY. Landed 1902.Bought in Market. ___. 413.0 ' 42;;'-418*0 j 413.0 398.0 ' 446'4 487.5 I 503.1 492'9 I 487'6 471.2 5 2 ~ ' Y 85'43 1 88.18 86.3; 85'43 (32'59 6'90 ~ 6.70 ' 7-10 6'80 16%0 73.8 1 85.8 12.3 11.9 2'5 j 2'0 120.8 I 89.0 139.5 I 139'1 348'9 1 327.8 78.0 81'2 14'2 , 14.4 2% , 2'0 107'1 94'0 1082 82'0 305'1 273'6 152.7 42'4 1 -7 182.8 258-8 638.4 !41 'ti4 11 '00 212'2 19.1 1'5 153.4 260'0 646'3 -I ++ Expressed as grarnmes per 100 litres of absolute alcohol present.74 THE ANALYST. Beet I slli.it, ~ Rum. I Whisky. I t is seen that the process of fractionation is to partially eliminate the secondary products. The analysis of the raw young brandy given probably does not exactly represent the finished product, as the first runnings and tailings are continually being returned to the still, and a circulation of ethers and higher alcohols is kept up, fresh ethers are developed, and existent ethers and alcohols are doubtless modified.The spirit is stored in casks for some years, and is then blended, reduced in strength by the addition of distilled water, coloured with caramel to enhance the colour gathered from the cask, and stored in huge vats, from which it i s drawn for export. I n Table 11. analyses of vintage brandies ( i e . , brandies which have matured in casks, and which are not yet reduced in strength and blended) are given. I t is seen that as brandy matures the furfural tends to diminish, and the other secondary products, especially acids and aldehydes, to increase. The increase is partly due to oxidation and partly to concentration, owing to loss of alcohol by evaporation.Except in the case of special quality " brandy, it is to be remarked that the composition is remarkably constant. The (' special quality " samples show all the signs of age- i e . , decreased furfural and increased acids and aldehydes to a great extent. I t is curious how the merchant who blends by the aid of his senses arrives at practical chemical constancy, indicating clearly that the quality of a brandy depends on the secondary constituents which can be estimated. Analyses of grain spirit, beet spirit, rum, whisky, and gin were made to ascertain the difference between brandy and its possible adulterations. The figures for these are given in Table IV. Analyses of typical brandies on the market are given in Table 111.TABLE IV. Analyses of Gmin S p i d , Beet Spirit, Rwnz, Whisky, Gin, and Rraitdy. Gin. I Three-star I Brandy. -___ ~- ~~~~ - ---- Alcohol per litre by weight Alcohol per litre by volume Proof spirit per cent. . . . Extract per litre ... ... Grain Spirit. 932.6 956.0 167.6 nil nil ~ 6-36 ~ 1.16 ' 0.52 ~ 6.70 ~--___-__-- Acids (as acetic acid)::: ... ~ 2.5 ~ 5.0 I 176-0 Ethers (asethylacetate):" j 3-6 ~ 18.6 1 443.1 Higher alcohols':' . . . ...I 2.9 1 7.3 , 93.9 l l . j ' 22 Furfural'l' . . . . ../ nil . j nil Aldehydes':' .. ... . . . 0.1 1 65.4 40.4 ~ 77.3 ~ 28.0 , 9.9 , 12.6 3.9 I 0.3 1.7 75.6 i 18.5 110.0 ' 239.7 27.9 1 120.6 -~ I.-- t Total secondary products'" ~ ----- 9.1 1 42.4 i 738.0 ~ 412.6 97.0 I 322.2 Brandy is characterized by containing at least 250 grammes of total secondary Of these the products per 100 litres of absolute alcohol, and usually about 300.* Exprcsscd as gramnics 1)cr 100 l i t i w of ;LI)soliitc alcohol pi'cseiit.THE ANALYST. 75 ethers and higher alcohols occur in sensibly equal proportions in the neighbourhood of 100 grammes each, departure from equality being usually due to the higher alcohols exceeding the ethers. Grain and beet spirits are comparatively free from secondary products, furfural especially being absent. Gin is also low in total secondary products, Rum is very high in ethers, and contains larger amounts of acids and furfural than brandy; whisky resembles brandy rather more closely, but the furfural is high, and the higher alcohols are about three times the amount of ethers, a ratio never attained in genuine brandy.Other samples of whisky from grain have been found free from ethers. The analysis of four samples of brandy purchased at public-houses and railway restaurants is given in Table V. : TABLE V. L I 11. 111. Alcohol per litre by weight ... ... 340.5 ' 382.8 432.4 _____ ---_-- Alcohol per litre by volume ... ... 407.9 1 454.1 ~ 508.2 Proof spirit per cent. ... ... ... 71.5 1 79.6 1 89.1 Extract per litre ... ... ... 7.1 14.9 ' 7.1 Acids (as acetic acid)* ".. ... 79.4 . 150.6 70-8 ... 0.6 j 0-4 1.0 Furfural* ... ... ... Ethers (as ethyl acetate)* ... ... 32.3 71.7 1 91.7 Higher alcohols* . , . ... .,. 49.0 58.7 1 98.3 Total secondary products* ... ... 168.7 288.0 , 273.6 Aldehydes* ... ... ... 7.4 1 6.6 11.8 - - _ _ _ _ _ I _ _ _ - / I i IV.I - 1 389.0 ! 471.3 1 82.6 1 6-6 .I - 91.6 5.9 0.7 80.2 113.1 291.6 - - . - No. 1 was a flavoured grain spirit, and was obviously not brandy. No. 2 was a mixture of rum and spirit, and showed the high acidity and No. 3 was a genuine brandy. No. 4 indicates a fair proportion of genuine brandy mixed with '( foreign " The Commissioner maintains that as brandy is so universally regarded as superior to all other spirits from a medicinal point of view, some control over the sale of substitutes for brandy should be established. A system of control would be possible if Public Analysts would give greater attention to the determination of the normal chemical characteristics of genuine brandy and the spirits used for adultera- tion than has hitherto been the case, comparatively high ether content characteristic of rum. spirit.H. D. R. The Determination of Glycerin in Wine. A. Trillat. (Ann. de Chim. anal., 1903, viii., 4-6.)-According to the author glycerin extracted from wine in the usual way by means of a mixture of alcohol and ether is very impure, containing from 5 to 12 per cent. of mineral matter. By tho use of acetic ether under the following * Expressed as grammes per 100 litres of absolute alcohol present.76 THE ANALYST. conditions this drawback is obviated : 50 C.C. of the wine are evaporated in a silver basin at a temperature of about 70" C. to about 35 c.c., when 5 grammes of animal charcoal are added, and the evaporation completed. The cold residue is ground in a mortar with 5 grammes of quicklime, and the resulting powder shaken for several minutes with 30 C.C. of acetic ether, free from water and alcohol.The solvent is decanted, the extraction repeated in order to remove the whole of the glycerin, the united extracts evaporated, and the residue dried at 60" C. until constant in weight (about 1& hour). The glycerin thus extracted is pale straw colour, and contains less than 1 per cent. of mineral matter. The author has used this method for several years, and has obtained good results even in the case of wines containing 30 grammes of glucose per litre. C. A. M. Analysis and Composition of Lemon- Juices. I(. Farnsteiner. (zeit. jur Unterswh. der Nahr. und Genusmittel, 1903, vi., 1-22.)-Analyses are given of pure lemon-juices, the results confirming those given by Borntraeger and Spaeth (ANALYST, 1898, xxiii., 176, and 1901, xxvi., 269).Instead of estimating the total extract by direct weighing, the author prefers the indirect way, by taking the specific gravity, and gives tables for calculating the extract from the latter. The figures so obtained agree with those of the direct method. Fermentation of the juice, besides decreasing the total extract, causes esters to form, this action also taking place in solutions of citric acid containing alcohol. Glycerin was found in both natural and artificial juices. w. P. s. Examination of Almond Oil and Almond Sweetmeats by the Ereis Test. A. Chwolles. (Chem. Zeit., 1903, xxvii., 33.)-The raspberry-red (tending to violet) colour which is given by peach-kernel oil when treated with Kreis' phloroglucinol and nitric acid test (ANALYST, 1902, xxvii., 330) enables the presence and the proportion of this material to be ascertained in almond oil.A genuine sample of the latter was prepared by means of ether from some Mogador almonds, which contained 50 to 75 per cent. of the bitter variety, and a second was made from pure sweet almonds from Majorca. The former gave a very faint colour with the Kreis test, the latter practically none at all. It is therefore possible to detect 10 per cent. of peach-kernel oil in almond oil, and, by simultaneously testing a mixture of the oils of known composition, to distinguish between a product containing 10 per cent. and one containing 15 per cent. of peach-kernel oil. The sweetmeat known as '' marzipan " is made from 2 parts of moist pounded almonds and 1 part of sugar, so that it should contain 50 per cent.of almond substance, 33.3 per cent. of sugar, and 16.7 per cent. of water. Occasionally a portion of the almond is replaced by peach kernels. To examine it, 200 grammes should be rubbed down with 100 C.C. of 95 per cent. alcohol, squeezed through a cloth, and the residue treated twice more with 100 C.C. of 80 per cent. spirit. The united extracts are brought into a separating funnel, shaken with ether and water, the ethereal solution of the oil filtered, and evaporated on the water-bath. The last traces of oil may be recovered from the cake by drying it and extracting with ether ;THE ANALYST. 77 but extraction of the original sample is more tedious than the process described.The oil is then tested as above indicated. The reaction has succeeded when applied to a mass of peach kernels and sugar a year old, appearing as at first. It is also given, though somewhat less strongly, by the oil of the " pipole," the seed of the pine which is native in Southern France and Spain. F. H. L. Notes on Some Essential Oils. J. Walther. (Farmax. J., 1902, xli., 751; through Chem. Zeit. Rep., 1902, 344.)-OiZ of A?ziseed.-This material can be valued by its specific gravity, its solidifying point, and its solubility in alcohol. As the anethol-content varies so largely, it would be better to use anethol instead of the oil itself. Paraffin and spermaceti in anethol or oil of aniseed are very clearly shown by the solubility in alcohol and by the higher melting-point.Stearine may be detected in the solidified oil by its crystalline form, or more conspicuously by shaking the sample with petroleum ether and a solution of copper acetate. Its value depends on the esters of linalool and geraniol, which, estimated by Kottstwfer's saponification method, should not be less than 32 per cent. in amount in good specimens. The specific gravity of the oil should be 0.880 to 0.886, and its rotatory power + 8" to + 20". Treated with an equal volume of 90 per cent. alcohol, it should yield a perfectly clear or but faintly turbid solution, which should not be altered in appearance by further additions of spirit. The residue on evaporation should be 6 per cent. Oil of Lavender.-The esters should be estimated by the same process as is used with oil of bergamot, and should amount to not less than 30 per cent. Terpene- less oils, however, contain less esters, because geraniol esters break up into their components during fractional distillation.French oil of lavender has a specific gravity between 0.883 and 0.895, is soluble in three volumes of 70 per cent. alcohol, and has an opticity of - 3 O to - 9". Essential oils containing phenols give sufficiently good results when examined by Kremers and Schreiner's method. Eugenol, the most important constituent of Oil of Cloves, may be estimated by converting it into its difficultly soluble benzoic ester (Thorns). Oils of Carraway and Mint.-Carvone cannot be determined in these oils by conversion into oxime according to the Kremers and Schreiner process, as a com- pound between carvoxime and hydroxylamine is liable to be produced. Still, when hydroxylamine hydrochloride is mixed with carvone in some indifferent solvent, treated with sodium bicarbonate, and heated under an inverted condenser on the water-bath, no loss of oxime occurs; the excess of hydroxylamine may then be titrated with sodium hydroxide, thus forming a very simple and exact method of determining carvone.The oxime of the laevo-rotatory carvone in oil of mint and that of the dextro-rotatory carvone in carraway are identical, melting at 71" C., and being optically inactive. The proportion of carvone in these two oils varies con- siderably, but in good specimens should be 50 per cent. Oil of Lemon.-In the valuation of this oil the most important points are the optical activity and behaviour on fractional distillation.A determination of the special Oil of Bergamot.-A physical examination of this oil is not sufficient.78 THE ANALYST. aldehydes, citral and citronellal, is not possible; but good results are to be obtained by converting them into oximes, and titrating the excess of hydroxylamine, It is necessary to modify the usual method slightly, for in presence of much hydrochloric acid the oximes are liable to ba partly converted into organic acids. For this reason a c iodometric titration of the hydroxylamine possesses advantages. The normal pro- portion of aldehydes in oil of lemon is about 5 per cent. Parry’s process with Schimmel’s modification requires a correction to be made, for on saponifying the products of acetylation, traces of acetic acid are liable to be left.Besides this estimation the physical constants muat be ascertained. Oil of SandaZwood.-In this oil the santalol must be determined. F. H. L. The Determination of Essential Oils in Absinthe. Sang16 Ferrihra and Cuniasse. ( A m . de Chirn. aiaal., 1903, viii., 17-18.)-Ons hundred C.C. of the absinthe are mixed with 10 C.C. of water, and rapidly distilled, a few pieces of pumice being used to prevent bumping. Fifty C.C. of the distillate (100 c.c.) are treakd as in the Hub1 iodine absorption method with 25 C.C. of a mixture of equal quantities of (1) iodine solution (50 grammes in a litre of 96 per cent. alcohol), and (2) mercuric chloride solution (60 grammes in a, litre of the same alcohol). A blank experiment is simultaneously made on 50 C.C. of alcohol of a strength approximating that of the absinthe. After three hours’ action a small quantity of potassiuin hydroxide solution is added, and the liquids titrated with & sodiuni thiosulphate solution. The digerenee between the number of C.C. required by the blank and by the actual determination, multiplied by the factor 0,2032, gives the amount of essential oils in grammes per litrc of absinthe. C. A. M. Colo-xr Reactions of Narceine. A. Wangerin. (Pharnz. Zed., 1‘302, xlvii., 916; through Chem. Zeit. Rep., 1902, 326.)-If 0-01 or 0.02 gramme of resorcinol is rubbed into 10 drops of pure strong sulphuric acid on a watch-glass and 2 or 5 milli- gramrnes of narceine are added, on stirring the mixture over a water-bath a fine carmine or cherry-red colour is produced. On cooling, the liquid changes from the edges first to a blood-red, and in twelve hours is orange-yellow. When 2 to 10 milli- grammes of narceine, 10 to 20 milligrammes of tannin, and 10 drops of strong sulphuric acid are warmed together on the water-bath, the liquid turns green; but a similar tint is given by narcotine and hydrastine. The firat test is said to be characteris tic. F. H. L.

ISSN:0003-2654    

DOI:10.1039/AN9032800072

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年代:1903

数据来源: RSC

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78 THE ANALYST. ORGANIC ANALYSIS. Estimation of Formaldehyde. H. Schiff. (Chem. Zed., 1903, xxvii., 14.)- About 10 grammes of the sample, supposed to contain some 38 or 40 per cent. of formaldehyde, are weighed out into a flask, diluted to 200 c.c., and neutralized. About 0-5 gramme of pure ammonium chloride is dissolved in 3 or 4 C.C. of water, and the solution is mixed with 10 C.C. of the aldehyde solution. ATHE ANALYST. 79 few drops of litmus tincture are added, and the whole is titrated with alkali. Two molecules of the latter are equivalent to 3 molecules of formaldehyde, the reaction being : 2NH,C1+ 3CH,O + 2KOH = N,(CH,), + 2KC1+ 5H,O. Exactly the same results are obtained if ammonium sulphate is employed instead of the chloride, the process giving slightly higher figures than the method of titrating with iodine.F. H. L. On the Relation of Hydriodic Acid and of its Salt3 t o the Starch and Dextrin Iodides. F. E. Hale. (Anzey. Chem. Joum., xxviii., 438.)-The author's experiments confirm the work of Mylius and of Lonnes on the ratio of iodine to hydriodic acid in blue starch iodide, which ratio was found to be as 1 to 4. I n the red starch iodide, on the other hand, which is formed by the action of iodine on starch in the presence of large quantities of potassium iodide, the ratio of hydriodic acid to iodine is as 1 to 2. The formula, of the blue starch iodide obtained by the author appeared to be [(C,H,,O,),,I],HI. He disagrees with Norris and Fay (Anwr. Chem. Jozmz., xxiii., 125), who found that the reaction between iodine and starch is more delicate at the temperature of 0" C.than at ordinary temperatures, and attributes their results to the fact that they overlooked the necessity of having suficient potassium iodide in the solution, the presence of which makes the starch indicator much more sensitive. A. G. L. Estimation of Glycogen in Yeast. J. Gruss. (Woch,ensch~. f iir Brauerei, 1903, xx., l-S.)-Two separate portions of the yeast, each weighing about 2.5 grammes, are placed in stoppered flasks. To one flask 100 C.C. of a 1 per cent. iodine solution are added, and, after repeated shaking, the contents are made up to 175 C.C. The yeast in the other flask is moistened and kept for twenty-four hours at a temperature of 30" C.; 100 C.C. of iodine solution are then added, and the mixture made up to 175 C.C.After settling, 20 C.C. of the supernatant liquid in each flask are titrated with standardized sodium thiosulphate solution, and quantities of iodine absorbed calculated for 100 grammes of yeast. The difference between the percentages corre- sponds to t h e glycogen, 1 per cent. of iodine being equivalent to 3.15 per cent. of glycogen. For the sake of comparing the quantities found in various yeasts, the glycogen should be calculated on the dry solids of the latter. The ratio 1 : 3.15 is an average value, as the extraction of the glycogen from the cells of various yeasts is not exactly uniform. Tv. P. s. Some Notes cmcerning Halphen's Test for Cottonseed 011. Elton Fulmer. (Joum. Amer. Chem. Soc., xxiv., 1148.)-The author finds that cotton- seed oil which has been heated to 260" to 270" C.does not react with Halphen's reagent, and that heating the oil to 220" to 240" C. greatly diminishes the intensity of the colour produced, whilst at the same time it appears reasonably certain from his experiments that heating to 240" C., and possibly even to 280" C., does not80 THE ANALYST. render the oil unfit for eating. He also shows that lard obtained from hogs fed on cotton-seed meal may give a colour with Halphen’s reagent equivalent to several per cent. of unheated cotton-seed oil, or to as much as 25 per cent. of cotton-seed oil subjected to a preliminary heating to 224’ C., even if the feeding of the animals with cot ton-seed meal had been interrupted for some considerable time (fifty-six days) before their slaughter. A.0. L. The Iodine Number of Sesame Oil. J. J. A. Wijs. (Xeit. fiir Untersuch. der Nahr. und Genussrnittel, 1902, v., 1150-1155.)-Thirty-seven samples of sesame oil pressed from seeds of various origins gave iodine numbers from 106.1 to 116.8, as determined by the iodine-chloride method. The oils from the (‘ second pressings ” gave numbers from 105.2 to 110.3, and the “third pressings” from 103.9 to 109.8. Previously published iodine (Hiibl) numbers of sesame oil lie between 102.7 and 115. w. P. s. The Iodine Number of Cod-liver Oil. J. J. A. Wijs. (Zeit. fiir Ulztersuch. der Nahr. und Geizussmittel, 1902, v., 1193-1196.)-Twenty-one samples of cod-liver oil examined by the author gave iodine numbers lying between 164.2 and 174.7, as estimated by the iodine-chloride method, using an iodine excess of about 70 per cent., and allowing the action to proceed for one hour.The specific gravities ranged from 0.9215 to 0.9240. The iodine numbers of thirty-five oils, sent to the author direct from the factories in Bergen, varied from 154.5 to 181-3, with specific gravities of 0.9202 to 0.9247. The Hubl numbers of these oils were from 6 to 10 per cent. lower than the iodine-chloride values. Four brown oils gave numbers (iodine chloride) between 155.0 and 162.2. w. P. s. Action of Diluta Mineral Acids on Oils : Sources of Error in Determining Glycerin by the Permanganate Method. (Chem. Rev. Fett- u. Harz- Ind., 1903, x., 6-10). - In determining, by the Benedict-Zsigmondy method, the amount of glycerin liberated from Turkey-red oils, the author finds that on boiling with dilute hydrochloric acid under a reflux condenser, the mineral acid attacks rubber or cork, forming substances that yield oxalic acid on subsequent oxidation with alkaline perrnanganate, and that it is therefore essential to have the condenser ground into the neck of the flask. Olive oil, and probably saturated glycerides, are not greatly affected by being boiled with dilute mineral acids, triolein, €or instance, being only hydrolysed to the extent of about 3 per cent.after one hour’s boiling. When sulphonated oils are boiled with dilute mineral acids, considerable amounts of glycerin are set free during the quantitative liberation of the combined sulphur. I n determining the glycerin by means of alkaline permanganate, the determina- tion must be made at the ordinary temperature, since soluble fatty acids also yield oxalic acid after a short time of heating.Unsaturated fatty acids, ether, and probably hydrocarbons of the series C.nH2,Li-2 also yield oxalic acid at the ordinary temperature, and must therefore be absent from the glycerin solution. W. Eerbig. C. A. M.THE ANALYST. 81 A New Method of Estimating Hydroxylamine Volumetrically. L. J. Simon. (Compt. Rend., cxxxv., No. 26 ; through Chem. ,Ve:us, lxxxvii., 47.)-The method consists in acting with a standard solution of potassium permanganate on, the oxalate of hydroxylamine, which is a, crystalline anhydrous salt only slightly soluble in water. The reaction takes place in two stages, the first of which is represented by the equation : 2KMn0, + 4[(NH,OH),EI,C,O,] = 2MnC,O, + 2HKC20, + N,O + 3N, + 15H,O.The oxalic acid is then oxidized to carbon dioxide, after the addition of sulphuric acid, in the second stage. A. G. L. Determination of Potassium i n Urine. W. Autenrieth and R. Bernheim. (Zeits. Physzol. Chem., 1902, xxxvii., 29 ; through Chem. Zeit. Rep., 1903, 5.)-The authors find that all human urines, normal or diseased, yield a precipitate of " cobalt yellow " [Co(N02),(KNa), + zH,O] when treated with De Koninck's reagent, sodium cobaltinitrite. As Gilbert has shown, the amount of potassium and of sodium in this precipitate varies considerably, but together they agree with the formula. Lithium, sodium, magnesium, calcium, strontium, and barium are not thrown down by the reagent.For the estimation of the potassium in urine, therefore, 50 C.C. of the filtered sample are mixed with 6 to 10 C.C. of the undiluted reagent (cf. Erdmann's Apzorganische Chernie, 1898, p. 630), well shaken, and allowed to stand for several hours, preferably all night. The cobalt yellow is collected on a fair-sized ashless paper, washed with cold water containing a little of the reagent, and dried at 110' or 120' C. I t is nest removed as completely as possible from the filter and brought into a porcelain basin; the filter is burnt in platinum, the ash extracted with hot water, and the filtered solution added to the basin. Then 10 or 15 C.C. of 25 per cent. hydrochloric acid are dropped in, and the basin is heated on the water-bath, gently at first, afterwards until an absolutely dry residue is left.This is moistened with water, stirred with 10 or 15 C.C. of a solution of perchloric acid free from sulphuric acid, and of about 18 per cent. strength, and heated on the water-bath till copious white fumes of perchloric acid appear and the residue is free from dust. The perchlorates of potassium, sodium, and cobalt are dried down and extracted, according to Wense'g process, with about 10 C.C. of 96 per cent. alcohol containing about 0.2 per cent. of perchloric acid ; the insoluble potassium salt is collected in a tared Gooch crucible, washed first with a few C.C. of alcohol containing perchloric acid, and then with a mixture of equal parts of alcohol and ether, till the washings leave no solid matter on evaporation.The crucible is finally dried at 120" C. to constant weight. I t is also possible to ignite the dried cobalt yellow gently in platinum until it is decomposed, separating the nitrites of potassium and sodium from the cobalt oxide by means of water, then treating the solution with strong hydrochloric acid and perchloric acid as already described. Or, the aqueous extract of the residue on ignition can be evaporated to a syrup with acid platinic chloride, and treated further as usual. By the foregoing process the authors have succeeded in directly determining the proportion of potassium in a highly albuminous urine. The method is much quicker82 THE ANALYST. than others, for after the cobalt yellow has been filtered off the operation only takes three hours.F. H. L. Estimation of Nitrogenous Constituents in Urine. E. Freund and R. Fellner. (Zeits. physiol. Chem., 1902, xlvi., 401; through Chem. Zeit. Rep., 1902, 342.)- By fractional precipitation with mercuric chloride in the manner described below, it is possible to separate the nitrogenous constituents in urine into a precipitate con- taining (a) the uric acid and the xanthine bases, and into a second containing ( b ) the creatinine and the ammonia, A special sample of the urine is first tested to ascertain what volume of saturated mercuric chloride solution is necessary to yield a yellow (not white or red) precipitate when sodium carbonate is afterwards added. This being found, 50 C.C. of urine are treated with hydrochloric acid in presence of 5 drops of a 1 per cent.solution of alizarine sodium sulplionate till a faintly acid reaction is shown, next the necessary quantity of mercuric chloride is introduced, and then, using dimethylamidobenzene as external indicator, the free hydrochloric acid is displaced by dropping in a very weak solution of sodium acetate mixed with acetic acid, the amount required being shown by the absence of an orange-red colour. The precipitate so obtained contains the whole of the uric acid and the xanthine bases, but is absolutely free from creatinine. On adding to the filtrate an equal volume of a 50 per cent, solution of sodium acetate, all the ammonia and the creatinine fall. They may be separately estimated by dissolving the precipitate in hydrochloric acid, determining the total nitrogen in one portion of it, and in another throwing out the ammonia by means o€ potassium iodide and hydroxide, removing the oxydimer- curiammonium iodide, and examining the filtrate by the Kjeldahl process; Or the amount of mercury can be estimated by titration with potassium cyanide and silver nitrate. Methods for recovering the nitrogenous compounds in the second main filtrate are now being sought.F. H. L. Chrome-hide Powder in Tannin Analysis. B. Weiss. (Gerber, 1902, xxviii., 104 ; through Chem. Zeit. Rep., 1902, 282.)-When chrome-hide powder is used in the analysis of tanning materials, higher results are obtained for the non- tannins ; while the differences caused by alterations in the conditions of testing- t ~ y . , concentration of the solution and quantity of the hide-powder-are much smaller than when ordinary hide-powder is employed. Dry chrome-hide powder only gives a, filtrate free from tannins when used upon dilute liquids containing 0.35 to 0.45 gramme of tanning substances per 100 C.C.F. H. L. Some Constants of Carbon Bisulphide. M. von Unruh. (Zeits. AnOrg. Chem., xxxii., 407.)-The author prepared perfectly pure carbon bisulphide by shaking the crude substance with dry mercury and a little calcium chloride, and then dis- tilling the liquid in the dark, the first and last portions of the distillate being rejected. These operations were repeated until no more mercuric sulphide could be obtained, the boiling-point of the liquid also remaining constant within 0.002" on redistillation.THE ANALYST. 83 The boiling-point of this pure carbon bisulphide was found to be 46-25' at 760 millimetres pressure, with a correction of 0*04144" for 1 millimetre mercury. The specific gravity at this boiling-point of 46.25" under 760 millimetres pressure was also determined, giving the value 1.2209. From these data the author calculates the constants of carbon bisulphide, to be used in determining molecular weight by means of the increase of the boiling-point, as 7G1 = 2370 for 100 grammes, and k, = 1940 for 100 C.C. A. G. L.

ISSN:0003-2654    

DOI:10.1039/AN9032800078

出版商:RSC    

年代:1903

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THE ANALYST. 83 INORGANIC ANALYSIS. Qualitative Separation of Arsenic, Antimony, and Tin. J. Walker. (Proc. Chem. Xoc., No. 258, December 17, 1902.)-The solution containing the mixed sodium thio-salts of arsenic, antimony, and tin is heated with sodium peroxide, and from the resulting solution of sodium arsenate, antimoniate, and stannate, tin is pre- cipitated as stannic hydroxide by boiling with excess of ammonium chloride. After the addition of excess of acid, antimony sulphide is thrown down by hydrogen sulphide in the cold, leaving arsenic in solution. A. G. L. Separat,ion of Lead from Manganese by Electrolysis. A. F. Linn. (dmer. Chem. Journ., xxix., 82.)-Having previously found (ANALYST, xxvii., 229) that lead can be completely separated electrolytically from a solution of its phosphate in phosphoric acid, whilst manganese is not deposited, the author now shows that under certain conditions the method affords a means of separating the two metals.For this purpose the solution containing lead and manganese as nitrates is pre- cipitated with a small excess of sodium hydrogen phosphate; thg phosphates are dissolved in excess of phosphoric acid solution (specific gravity 1-70), and the solution electrolysed for about eighteen hours at the ordinary temperature, using a current of N.D. The dilution should be about 0.1 gramme of metal in 130 C.C. The deposii of metallic lead is washed, first with air-free water, then with alcohol and ether, and is weighed after being dried at 100" to l l O o C. A small amount of hydrated peroxide of manganese is always found on the anode.A. G, L. = 0.005 amphre, and 2.5 volts. The Determination of Manganese in Steel wnd Iron. John V. R. Stehman. (Jozim. dmer. Chent. SOC., xxiv., 1204.)-The following method is a modification of that described by Walters (ANALYST, xxvii., 27), the difference being that the per- manganic acid formed is determined by means of a solution of sodium arsenite instead of colorilnetrically : I n a 6-inch test-tube 0.2 gramme of the pig-iron is dissolved in 10 C.C. nitric acid (specific gravity 1.20); the solution is boiled t o expel nitrous fumes, filtered into a larger test-tube, the filter being washed twice with hot, very dilute nitric acid, and then with 15 C.C. of a solution silver nitrate containing 1.33 grammes per litre.One gramme of damp ammonium persulphate is then added, the solution heated and kept boiling for one minute after oxidation has commenced, After cooling rapidly in a stream of water it is washed out with84 THE ANALYST. 30 or 40 C.C. of water into a beaker, 5 C.C. of saturated sodium chloride solution are added to precipitate the silver, and the titration is immediately carried out with standard sodium arsenite solution, which is standardized preferably against a standard permanganat e solution. A determination as above takes about twenty-five minutes. I n the case of steels, filtration is unnecessary, and even less time is required. The test results given are satisfactory. A. G. L. A Simplified Method of Determining Zinc as Sulphide. A. Thiel. (&its. artorg.qhem., xxxiii., 1.)-The chief advantage of this method lies in the fact that the tedious filtration of the precipitated zinc sulphide is avoided, the precipitate being washed from the flask in which it is thrown down into another smaller one of Jena glass, in which it is then ignited in a current of hydrogen sulphide, the ignition being completed in a current of hydrogen. The precipitation is effected by adding to the neutral solution of the zinc salt, contained in a round-bottomed flask, a fair amount of ammonium acetate, and then an excess of hydrogen sulphide water, after which the whole is boiled vigorously for two minutes. The precipitated zinc sulphide settles in a very short time, and as soon as this has taken place almost the whole of the supernatant liquid may be decanted through a quick-filtering filter-paper.If the solution contains fixed impurities in any considerable quantity, which is not often the case in the analysis of zinc-blendes, the precipitate is purified either by heating to boiling once or twice with H,S water, and decanting, or else by solution in hydro- chloric acid, followed by renewed precipitation. The zinc sulphide is finally washed into a 50 C.C. Erlenmeyer Jena-glass flask, and the whole heated to dryness in a, water-bath, evaporation of the water being facilitated by blowing a current of air into the flask. After adding the ash of the filter-paper, the contents of the flask are dried for a short time at 120" C., and then heated to redness, first for about an hour in a current of pure hydrogen sulphide, and then for a few minutes in a current of dry hydrogen, in which they are also allowed to cool.During the heating the flask is pro- tected from direct contact with the flame by means of a mantle of asbestos, through which only the products of combustion pass. The method gives excellent results in a comparatively short time, and the author recommends heating the sulphides of other metals--e.g., copper-in a current of hydrogen sulphide instead of using a current of hydrogen and adding sulphur, which volatilizes at too low a temperature. A. G. L. A Rapid Method for separating Zinc and the Alkaline Metals from Iron. H. c. Babbitt. (Joz~rn. Amer. Chem. SOC., xxiv., 12ll.)-The author states that the now well-known method due to Rothe of extracting the hydrochloric acid solution of the mixed chlorides with ether is applicable to the separation of zinc and the alkaline metals from iron, only a small amount of iron remaining with the zinc. If lead is also present, it is best previously separated as sulphate, the presence of a small amount of sulphuric acid not affecting the separation.No analytical data are given. A. G. L.THE ANALYST. 85 Analysis of Ferro-Nickel Briquettes. J. H. James and J. M. Nissen- (Journ. SOC. Chem. Ind., 1903, i., 3.)-CuO, NiO, and P20,.-One gramme of the powdered sample is dissolved in hydrochloric acid. The solution is evaporated until pasty, 5 C.C. of concentrated sulphuric acid are added, and the mixture is heated. The product is treated with 50 C.C. of water, and filtered.The residue is fused with four times its bulk of sodium carbonate, and the fused mass dissolved out with dilute sulphuric acid. The combined solutions are almost neutralized with ammonia, 3 C.C. of strong nitric acid are added, and the copper is deposited by electrolysis. The solution from the copper deposition is treated with hydrogen peroxide, boiled, and the iron is separated from the nickel by precipitation three times with ammonia, dissolving each time with warm dilute sulphuric acid, and washing at least eight times with hot water at each precipitation. The final precipitate, which contains the phosphorus as ferric phosphate, is dissolved in warm nitric acid (I : l), and the phos- phorus is determined in the usual way. The first filtrate from the iron separation is evaporated down with sulphuric acid, the other filtrates and washings are added.The whole is made strongly ammoniacal, and after dilution, if necessary, to about 450 C.C. the nickel is deposited by electrolysis with a current of 0.5 ampAre per 100 square centimetres. SiOz, A1203, CaO, MgO. - Two gramrues are dissolved in hydrochloric acid, the solution evaporated to dryness, the residue baked, and re-dissolved in dilute hydrochloric acid ; the siliceous residue is fused with sodium carbonate, dissolved in dilute hydrochloric acid, and the liquid is evaporated to dryness. The residue is again taken up with dilute hydrochloric acid and the silica filtered off. To the filtrate nitric acid is added, then 2 grammes of ammonium chloride, and then excess of ammonia.The Precipitate is filtered off, washed, re-dissolved in dilute sulphuric acid. The solution is made just alkaline with ammonia, and the precipitate is re-dig- solved in the smallest excess of sulphuric acid. The solution is diluted to about 500 c.c., and 200 grammes of pure mercury are placed in the bottom of the beaker to serve as a cathode for the electro-deposition of the iron, using a current of 2 amp8res. When all the iron has been deposited the solution is poured off, 1 gramme of ammonium chloride and a slight excess of ammonia are added, and the aluminium is determined in the usual way. CaO, Mg0.-A large excess of ammonia is added to the filtrate from the above to prevent the precipitation of copper and nickel. Then the calcium is precipitated as oxalate, which i s filtered off and estimated by titration with permanganate. The filtrate and washings are evaporated to small bulk, concentrated nitric acid is added, and the evaporation is continued to dryness.The residue is dissolved in a little water, ammonia is added, and the magnesium is precipitated as magnesium ammonium phosphate. SO3, Fe,03.-One gramme is fused with 9 grammes of a mixture of ten parts sodium carbonate and one part potassium nitrate. The melt is dissolved in hot water, the residue is treated with diliite hydrochloric acid (1: l), and the iron is separated from the greater part of the copper and nickel by precipitating with ammonia. The ferric hydroxide is dissolved, and the iron is titrated by any of the usual methods. The filtrate is evaporated to dryness, taken up with water, filtered to remove silica, and sulphur is precipitated as barium sulphate.86 THE ANALYST.VOLATILE &tATTER.-The material is heated in an open platinum crucible. The loss represents organic matter, water, and practically all the sulphur trioxide. If tar, pitch, or other organic material has been used in the manufacture of the briquettes, two or three times as much nitre should be used for the fusion in the determination of sulphur and iron, and for each of the other sets of determinations the material should be ignited beforehand. A. M. The Use of Hydrogen Peroxide in Volumetric Analysis. Schlossberg. (Zeit. anal. Chem., 1902, xli., 735-747).-The manganese in manganese salts can be determined by converting it into manganese dioxide by means of hydrogen peroxide in alkaline solution, MnS04 + 2KOH + H,O, = K,SO, + 2H,O + MnO,, and reducing the dioxide by means of an acid solution of hydrogen peroxide.The excess of hydrogen peroxide is then determined by titration with potassium permanganate. The total amount used is divided by two in order to obtain the equivalent amount of manganese. Free hydrochloric acid, if present, must be removed by boiling. The active oxygen in lead peroxide and red lead can be determined in an analogous manner, the reaction in this case being Pb02 + HzOB + HaSO, = PbSO, + 2HzO + 0, From 0.5 to 0.7 of the lead oxide are treated with a nitric acid solution of hydrogen peroxide of known strength; 10 C.C. of dilute sulphuric acid are then added to the solution, and the excess of hydrogen peroxide titrated with standard permanganate.For the determination of the metal in lead salts, lead peroxide is first formed by treatment with bromine and potassium hydroxide, and then reduced by treatment with an acid solution of hydrogen peroxide. I n the case of mixtures of lead and copper salts the lead is converted in this way into lead peroxide, and the precipitate collected, washed, and reduced with the standard hydrogen peroxide. I t is also possible to separate the lead as sulphate from mixtures of the salts of lead with other heavy metals, and to convert the lead sulphate into lead peroxide, which is deter- mined as described above. C. A. M. Determination of Sulphur by Means of Hydrogen Peroxide. J. Petersen. (Oversigt over Videnskabemes Selskctbs Forhandlinger, 1902, v., 191 ; through Chem.Z~ic. Rep., 1902, 355.)--In the case of gunpowder, the sample is boiled with an alkali in order to bring the sulphur into solution as a sulphide, then oxidized with hydrogen peroxide, and the sulphuric acid thrown down from an acid solution with barium chloride as usual. For greater accuracy, the acid liquid must be filtered from the carbon, and evaporated to dryness to remove the nitric acid before adding the precipitant. In many organic compounds, such as thiourea, allylthiourea, thio- carbanilide, potassium xanthate, dixanthogen, carbon bisulphide, potassium thio-THE ANALYST 87 cyanate, eta, the sulphur may be determined by dissolving the material in I00 C.C. of water or 80 C.C.of alcohol, and treating with 10 C.C. of 8 per cent. sodium hydroxide and 50 C.C. of a 3 per cent. solution of hydrogen peroxide. After driving off the alcohol on the water-bath, water and hydrochloric acid are added, and the sulphuric acid precipitated as usual. There are, however, many organic compounds, such as thiophen, ethyl sulphide, thiophenol, and ethyl thiocyanate, in which the sulphur is not converted into sulphuric acid by the author's process. In esters of thiocarbonic acid, for instance, where it might be expected that one atom of sulphur should behave differently from the others, one-third of the sulphur is recovered by the method described. F. H. L. The Determination of the Strength of Sulphuric Acid. A. Marshall. ( J o z L ~ . SOC. Chem. Id., 1902, xxiv., 1511.)-An extension of the method referred to in ANALYST, 1900, xxv., 307.I n the case of concentrated acids the strength cannot be deduced directlyfrom the specific gravity with a sufficient degree of accuracy. A quantity of the acid should be weighed out, diluted with half its volume of water, weighed again and its specific gravity taken. If the impurity present do not amount to more than 0.01 per cent,, the strength of the diluted acid may be obtained at once from the table in the previous paper (see Journ. SOC. Chem. Ind., 1899, 4, 1091). This strength multiplied by the weight of diluted acid and divided by the weight of the original acid gives the percentage of H,SO, in the latter. If impurity be present a correction must be applied. A portion of the diluted acid is evaporated down in a weighed platinum dish, the percentage of mineral residue is multiplied by 1.4, and the product is subtracted from the strength of the dilute acid found as already described.Thus, to take an actual instance, 54-764 grammes of an acid were taken and diluted with water to 69.620 grammes. The diluted acid was found to leave 0.21 per cent. of residue on evaporation, and the clear settled liquid had a specific gravity of 1.6888 at 15/15' C. in air, corresponding to 76.20 per cent. The true percentage therefore was 76.20 - 0.21 x 1.4 = 75.91, and the strength of the sample was 75-91 x 69.620~ 54.764=96.50 per cent., agreeing exactly with the figure obtained by titration. If there be any considerable quantity of arsenic present, the percentage of As203 should be multiplied by 1.6, and the product be subtracted as already described.Where only approximate figures are required the specific gravity can be taken with a hydrometer, and the quantities of acid and water can be measured instead of being weighed, provided they are occasionally checked. Where a constant method of procedure is adopted, and the same quantities of acid and water are always taken, a table can be constructed which for each specific gravity gives at once the strength of the original acid. The strength of sulphuric acid can also be approximately determined from the contraction which takes place on diluting with water. I n a 300 C.C. graduated flask are placed 100 C.C. of water. A funnel is placed in the neck of the flask, and on to the water is rapidly poured 200 C.C. of the sulphuric acid measured at 15" C.The liquid is mixed and cooled to 15", and the contraction is measured by running in88 THE ANALYST, paraffin oil from a burette. The following table gives the contraction for acids of different strength : H,SO,. Per cent. 98 97 96 95 94 93 92 91 90 89 88 87 86 Contraction of 200 C.C. with 100 C.C. of water. C.C. 24.1 22.6 21.2 19.8 18.5 17-3 16-1 15.0 13.9 12.9 12.0 11.2 10.4 A. M. The Influence of Impurities on the Specific Gravity of Sulphuric Acid. A. Marshall. (Journ. SOC. Chem. Ind., 1902, xxiv., 1508.)-Concentrated sulphuric acids obtained from different sources being found to vary in strength, although there was no great difference in the specific gravities, the author has investigated the effect SPECIFIC GRAVITIES OF MIXTURES OF SULPHURIC AND XITRIC ACIDS.Per Cent. Nitric Acid. of impurities on the gravity. In the case of re-concentrated acids, it was found that the density was raised by the presence of mineral impurities. New acids obtained directly from the manufacturers, on the other hand, in many instances contained small quantities of nitric acid, due probably to the containing vessels having beenTHE ANALYST. 89 used for waste acids. The presence of nitric acid causes an increase in the specific gravity up to 7.5 per cent. HNO,, above which it causes it to fall again, as is shown in the accompanying curve, which represents the specific gravities of mixtures made by the addition of strong nitric acid (94.0 per cent.strength) to strong sulphuric acid (96% per cent.), The author has made a considerable number of experiments to ascertain the influence of common impurities on the densities of acids of strengths varying from 70 to 100 per cent. The results are given in the following table, which indicates the actual alteration caused by the addition of 0.1 per cent. of the various substances. I t should, however, be borne in mind that the acids with 0.1 per cent. impurity neces- sarily contain nearly 0.1 per cent. less H2S04 than the pure acids with which they are compared. For convenience, nitrous acid was added in the form of nitroso- sulphuric acid (chamber crystal). EFFECT OF IMPURITIES ON SPECIFIC GRAVITY OF H2S04. Strength. Na2S0, ... CaSO, ... AI,(SO,), ... Fe2( SO,), . . . PbSO, ... MgSO, ... As,O, ... HSNO, ... 100 per Cent. 0~0011 0.0012 Insoluble Insoluble 0.0017 0*0011 0*00029 - 98 per Cent. 0~0010 0.0011 Insoluble Insoluble 0.0014 0*0010 0.0013 0.00027 94 per Cent. 0*0007 0.0009 Insoluble 0.0006 ? 0.0015 0.0012 - - 80 per Cent. 0.0008 0.0007 0.0012 .? 0-0008 Insoluble 0*0009 0*0010 0.00023 70 per Cent. 0.0007 0.0006 0.0011 0*0007 Insoluble 0~0009 - - The author has recalculated Pickering's table of the specific gravities of sulphuric acid (Jounz. Chem. SOC., 1890, lvii., 154). He gives the percentage of H2S04 cor- responding to each variation of 0.001 in the specific gravity, the latter being taken at 15" C. and compared to water at the same temperature. The weights are not corrected for air displacement. This correction is easily made by means of the formula : S , = S, - a(S, - I), where S,, S, are the specific gravity in vacuo and in air respectively, and a is weight of unit volume of air. In the case of a substance heavier than water, the correction to be subtracted is obtained by multiplying the decimal portion of the specific gravity by the density of air (0.0012). For this table see the original paper. A. M.

ISSN:0003-2654    

DOI:10.1039/AN9032800083

出版商:RSC    

年代:1903

数据来源: RSC

摘要:

THE ANALYST. 89 A P PAR ATU S. The Calibration of Burettes. Launcelot W. Andrews. (Amer. Chem. Journ., xxviii., 491.)-The burette is standardized by the aid of a piece of glass rod, having a ring at its upper end, by means of which it may be suspended from a fine silk or metal wire. The volume of the glass rod is exactly 5 c.c.-that is, when suspended in water at 20" C. it weighs 4.987 grammes less than when weighed in air. The factor 4.987 includes corrections due to the buoyant effect of air on brass weights, etc. The90 THE ANALYST. final adjustment of the volume of the glass rod is made most easily by grinding down the lower end until the rod attains a certain weight in air, which may be calculated from the volume and the specific gravity of the glass. The method of calibration employed is obvious.A. G. L. Tube for use with Hydrometer. C. Hehn. (Zeds. f. angew. Chem., 1902, xv., 1118.)-A frequent source of inaccuracy in the determination of the specific gravity by means of the hydrometer is the non-vertical position of the cylinder used. The author describes a device for overcoming this diffi- culty, the cylinder being ma;de to assume the vertical position by its own weight. The thickened rim of the glass cylinder fits into a metal ring, suspended, after the manner of a ship’s compass, from a second ring. A. M. use the gas flame should be placed under a spot in the annular base of the boiler until steam is up ; then the burner should be moved into a central position. Generation of steam may be diminished by inserting a layer of asbestos sheet between the coil and the inner wall of the boiler ; or, if preferred, the surplus steam can be blown off from the side tube on the safety funnel.Suitable dimensions are : Height, 18 centimetres ; width of annulus, at bottom, 4 centimetres ; at top, 5.5 centimetres ; internal diameter of coil, 7 millimetres ; diameter of hori- A Laboratory Steam Superheater. J. Freundlich. (Chem. Zed., 1902, xxvi., 1084.)-This is an apparatus for raising steam and superheating it by means of one single burner, its method of construction being apparent from the sketch. The superheating coil, however, should be fitted, on the top of the boiler, with a pair of unions, so that it can be taken out for cleaning, etc. When bringing the apparatus into 7 zontal tubes, 15 millimetres ; maximum diameter of trumpet mouth, 22 millimetres ; ength of ditto, 10 centimetres.F. H. L.TEE ANALYST. 91 An Immersion Refractometer (Zeiss). H. Matthes. (Zeit. fur Untersuch. der Nahr. und Genussmittel, 1902, v., 1037-1043.)-The general form and manner of using the instrument are shown in the illustrations. In Fig. 1 the prism of the refractometer is immersed in the solutions contained in beakers which are kept at the proper temperature (17.5" C.) by the bath A. The latter has a ground-glass plate at the bottom, through which the light is reflected by the mirror below. I n the case of volatile liquids, or those affected by exposure to the air, a cap, D (Fig. 2) is provided, fitting over the prism, and in which the liquid to be examined is placed, FIG. 1. the instrument being then immersed in the water-bath 23, the latter having B glass side G, through which the light is reflected. The prism P has a refractive index of 1-51 and an angle of 639 The scale, which has a range from -5 to +105, corre- sponding to refractive indices from 1.32539 to 1,36640, is read through the ocular Oc (Figs. 1 and 2). A micrometer adjustment, 2, is provided to increase the accuracy of the readings. The latter are compared with tables to obtain the strengths of the solutions examined. Tables have been worked out for solutions of the following92 THE ANALYST. substances : The chlorides, bromides, and iodides of potassium and sodium, hydro- chloric acid, sulphuric acid, nitric acid, phosphoric acid, acetic acid, formaldehyde, glucose, beer-extract, wine-extract, etc. The instrument may also be used for determining the shrength of alcohol. w. P. s.

ISSN:0003-2654    

DOI:10.1039/AN9032800089

出版商:RSC    

年代:1903

数据来源: RSC

摘要:

92 THE ANALYST. REPORT OF THE DEPARTMENTAL COMMITTEE APPOINTED TO CONSIDER SCHEDULE A TO THE PHARMACY ACT, 1868. THIS committee-which consisted of Sir Herbert Maxwell, Bart., M.P., Chairmen ; Alexander Cross, Esq., M.P. ; Professor T. E. Thorpe, C.B., F.R.S. ; Professor W. A. Tilden, F.R.S. ; Thomas Stevenson, Esq., M.D. ; William Martindale, Esq., F.C.S. ; and J. H. Harrison, Esq.-has concluded its investigations, and reports the alterations which it deems advisable in Schedule A to the Pharmacy Act of 1868. The principal report is signed by six members of the committee, a supple- mentary report by Mr. A. Cross, and a minority report by Mr. Walter Hills (who replaces Mr. W. Martindale, deceased). The whole may be obtained through any bookseller for twopence.

ISSN:0003-2654    

DOI:10.1039/AN9032800092

出版商:RSC    

年代:1903

数据来源: RSC