摘要:

THE ANALYST'. MARCH, 1904. PROCEEDINGS OF THE SOCIETY OF PUBLIC ANALYSTS. THE annual meeting of the Society was held on Wednesday evening, February 3, in the Chemical Society's Rooms, Burlington House. The President, Mr. Thomas Fairley, occupied the chair. The minutes of the previous meeting were read and confirmed. Messrs. B. Kitto and H. Droop Richmond were appointed to act as scrutators of The HON. TREASURER (Mr. E. W. Voelcker, A.R.S.M.) presented his report for the Mr. EKINS moved the adoption of the report, and proposed a vote of thanks to Mr. NIMMO seconded, and the motion was carried unanimously. The HON. TREASURER having responded, Dr. LEWKOWITSCH proposed, and Mr. W. T. BURGESS seconded, a vote of thanks The proposition was carried unanimously. The PRESIDENT moved that a vote of thanks be accorded 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.The motion, on being put to the meeting, was carried unanimously. The PRESIDENT delivered his annual address. Dr. VOELCKER proposed a vote of thanks to the President for his address, ooupled with a request that he would allow it to be printed in the proceedings of the Sooiety. Dr. DYER seconded, and the proposition was carried unanimously. The PRESIDENT having responded, A vote of thanks, on the proposition of Dr. SCHIDROWITZ, was unanimously passed to the Hon. Secretaries, Mr. E. J. Bevan and Mr. Alfred C. Chapman, for their services during the past year. the ballot-papers for the eIection of officers and Council for 1904.year 1903. the Hon. Treasurer for his services during the past year. to the auditors, Mr. John Hughes and Mr. W. P. Skertchly. Mr. BEVAN acknowledged the vote of thanks. The scrutators having reported the result of their examination of the ballot- papers, the President announced the unanimous election, for the ensuing year, of ofljcers and Council as follows : President : ThomasFairley. Past Presidenk (limited by constitution to ten in nu.mber) : M. A. Adams, A. H. Allen, A. DuprB, Bernard Dyer, W. W. Fisher, Otto Hehner, Alfred Hill, J. Muter, Thomas Stevenson, J. Augustus Voelcker.70 THE ANALYST. Vice-Presidents : Bertram Blount, Sidney Harvey, E. Wallis Stoddart. Hon. Treasurer: E. W. Voelcker.Eon. Secretaries: E. J. Bevan and A. C. Chapman. Other Members of Cozlncil: L. Archbutt, H. Ballantyne, W. T. Burgess, R. Hellon, 2. T. Holloway, F. J. Lloyd, Raymond Ross, P. Schidrowitz, J. E. Stead, D. A. utherland, R. R. Tatlock, L. T. Thorne. The ordinary monthly meeting of the Society was held on Wednesday evening, February 3, in the Chemical Society’s Rooms, after the termination of the annual meeting. Certificates of proposal for election to membership in favour of Messrs. F. E. King, B.Sc., and W. H. Simmons were read for the second time ; and certificates in favour of Messrs. John Edward Jenkins, A.I.C., 82, Anerley Park, S.E., works chemist to Messrs. Yerttman and Co., Ltd., ; Arnold Rowsby Tankard, assistant to Mr. A. H. Allen, 67, Surrey Street, Sheffield; Arthur Tighe, 30, Marlborough Place, St. John’s mood, N.W., assistant to Mr. A. C. Chapman; and Francis Langston Watt, A.R.C. Sc., 111, Lrtuderdale Mansions, Lauderdale Road, Maida Vale, W., assistant to Mr. A. C. Chapman, were read for the first time. Messrs. F. Hudson-Cox, N. van Lam, J. S. Maclaurin, D.Sc., and T. A. Night- scales were elected members of the Society. The following papers were read: “Note on Chinese Tallow-seed Oil,” by L, Myddelton Nash ; L t Note on the Estimation of Mechanical Woodipulp in Paper,” by C. F. Cross and E. J. Bevan ; and a Note on the Analysis of Jam,” by Raymond Ross. The President, Mr. Thomas Fsirley, occupied the chair.

ISSN:0003-2654    

DOI:10.1039/AN9042900069

出版商:RSC    

年代:1904

数据来源: RSC

摘要:

70 THE ANALYST. THE PRESIDENT’S ANNUAL ADDRESS. (Delivered February 3, 1904.) THE past year has been one of steady progress in our Society, and good work has been done. We elected during the year twenty-one new ordinary members, and two members have resigned. Thus we have a net addition of nineteen new names to our list of ordinary members, which now stands at 296. We have elected one honorary member, Dr. J. Millar Thomson, F.R.S., Professor of Chemistry at King’s College, London, lately President, and for many years Registrar, of the Institute of Chemistry. Dr. Miller Thomson’s valuable services to the cause of professional chemistry and his high reputation make us glad to welcome him to a position in our list of honour. One whose duties brought him into touch with those of Public Analysts, and who earnestly strove to secure efficiency in his own department, has passed away- the Right Hon.R. W. Hanbury, the late Minister for Agriculture. The finances of the Society are in a, satisfactory condition, and our thanks are due to the honorary treasurer, who has informed me that our income has exceeded There has not been any loss by death during the year.THE ANALYST. the expenditure by 672. This compares favourably with the balance of lsat year, which was $47. At the same time, we have spent on the ANALYST 650 more than in the previous year. I think you will agree with me that additional expenditure could not have been laid out to better purpose. The membership and corresponding income controls the size of our Journal, but within this limit our aim must be to make it as perfect a record as possible of the progress in analytical chemistry.The following papers have been presented to the Society during the year : Apparatus for Making Anaerobic Cultivations in Fluid Media.” By Walter H. ‘‘ On the Determination of Glycerol in Crude Glycerines.” By J. Lewkowitsch, (‘ Note on the Determination of Casein precipitated by Rennet.” By H. Droop (‘ A Plea for the More Extended Consideration of Physics in Analyticd Methods.” Jolly man. M.A., Ph.D. Richmond. By H. Droop Richmond. ( ( Note on Adulterated Beeswax.” By Otto Hehner. ‘( The Solubility of certain Salts in Ether.” (‘ Recent Advances in the Bacteriological Examination of Water.” By W. H. (‘ The Ash of British Pharmacopceia Drugs.” By William Chattaway and C.G. (‘ Existing Defects and Possible Improvements in the Laws relating to Adultera- “ The Composition of Milk.” “ Note on the Determination of Mineral Oil in Resin Oil.” By J. Lewkowitsch, M.A., Ph.D. “ The Detection and Estimation of Mineral Acids in Acetic Acid and Vinegar.” By Philip Schidrowitz, Ph,D. “ A Case of Pollution by Wood-pulp Sulphite Liquor,” and “Note on some Reactions of Sulphite Wood Liquor.” By E. J. Bevan, Bertram Blount. and Otto Hehner. “ Some Methods of Discriminating between Egyptian and Bombay Cotton- seed Cakes,” and ‘‘ Hair-balls in Sheep.” By J. Augustus Voelcker, M.A., Ph.D. ‘( The Determination of Available Phosphoric Acid and Potash in Calcareous Soils.” By H. H. Cousins, M.A. (Oxon), and H. S. Hammond. ‘‘ Note on a Reaction for Nitrites.” By W.A. Blunt. “ The Salinity of Waters from the Oolifes.” By W. W. Fisher, M.A. ‘‘ Some Indian Oils.” By J. Lewkowitsch, M.A., Ph.D. “ Differentiation of Linseed Oil from Boiled Oils.” By J. Lewkowitsch, M.A., Ph.D. “ Note on the Purification of Hydrochloric Acid and Zinc from Arsenic.” By L. T. Thorne, Ph.D., and E. H. Jeffers. Note on some Vanadium Reactions.” By C. A. Mitchell, B.A. (Oxon.). By Otto Hehner. Jolly man. Moor, M.A. (Cantab.). tion.” By Alfred H. Allen. By H. Droop Richmond.72 TEE ANALYST. “The Characteristics of aome Almond and Allied Oils.” By J. Lewkowitech, ‘( Note on the Examination of Sperm Oil.” By L. Myddleton Nash. “ The Estimation of Aldehydes and Ketones in Essential Oile.” By Herbert E. The following exhibits were shown at the meetings : ‘ I Seal with Moveable Letters and Figures for Samples taken under the Sale of Food and Drugs Acts.” “ Radium Bromide and its Emanations as shown by the Spinthariscope and Screen coated with Barium Platinocyanide, also Photographs taken by and illustrating the Penetrating Power of the Rays from Radium.” By T.Fairley. The following reprints have been issued by permission from the Chemical Society : ‘‘ The Estimation of Arsenic in Fuel.” By T. E. Thorpe, C.B., F.R.S. “ The Electrolytic Estimation of Minute Quantities of Areenic, more especially Also reprinted from circular issued by the Board of Agriculture : M A , Ph.D. B urgese. By W. Chattaway. in Brewing Materials.” By T. E. Thorpe, C.B., F.R.S. Analyses of Reserved Milk Samples.” These papers do not quite come to the proportion of one paper to ten of our members.One of the most important papers of the year, involving a very great amount of work, was that by Mr. Fisher “ On the Salinity of Waters from the Oolites.” This research must be of the greatest value to all who are interested in underground wstere, especially those of the Oxfordshire district and the Thames Valley. Both geologists and chemists will anxiously watch for a continuance of Mr. Fisher’s work in this direction. Mr. Jollyman’s paper on ‘‘ Recent Advances in the Bacteriological Examination of Water ” attracted much interest, as he claimed a stronger position for bacterio- logical examination than chemists as yet are prepared to admit. Mr. Droop Richmond’s annual report on the ( ( Composition of Milk ’’ analysed during the year is valuable as affording cumulative evidence of the constancy of the composition of milk titken under normal conditions.I n ‘‘ Food and Drugs Analysis ” we have had comparatively few papers bearing on the subject during the year. “The Ash of British Pharmacopmia Drugs,” by Messrs. Chattaway and Moor, and “ The IMection rmd Hstimation of Nineral Acids in Acetic Acid and Vinegar,” by Dr. Schidrowitz, are the only papers bearing directly on the subject, though Dr. Voelcker gave two interesting communications bearing on animal foods. The subjeot of oil analysis ha8 been prominently before the Society at many of the meetings. The darkness and uncertainty which has l a g clouded this branch of our work is being gradually,zemoved by the researuhes of Messrs. Hehner, Lewko- witsch, and others, who devote themselvas,specially to this subject.I shall refer later to Mr. Allen’s paper on. the laws relating to adulteration in another part of this address.THE ANALYST. 73 I n addition to these original papers and reprinta, abatracts of the following papers have been given in the Journal : Food and drugs analysis ... ... ... ... ... 120 Toxicological analysis , . . ... ... ... ... 5 Organic analysis ... ... ... ... ... 126 Inorganic analysis ... ... ... ... ... ... 181 Apparatus ... ... ... ... ... ... ... 38 Total number of abstracts ... ... ... 470 -- Also there was printed (ANALYST, vol. xxviii., p. 165) a High Court decision in a case under the Sale of Food and Drugs Acts relating to the decomposition clause in the certificate.The original papers, although their number has been exceeded in some paet years, are yet of considerable value and importance. I n thanking the authors for .each of their contributions, I would point out that the fact of there being some willing workers in our Soeietydoes not relieve the rest of us from trying to contribute papers, and so adding even a little to the common good. The careful study and comparison of methods and the determination of constants under properly-specified conditions are not less important than new discoveries. There is great need for analytical revision in many directions, and, in connection with a scheme which has received the warm approval of the Council, a small fund has been established for the pul’pose of defraying out-of-pocket expenses.Several investigations are at present in progress under this scheme. We are falling behind both Germany and America in research work in analytical chemistry, and each member of this Society should do his utmost, not only to remove this reproach, but to seek to restore to’ us a fmnt rank in the cultivation of this branch of our science. The work dione in the editing of papers and abstracts in the Journal maintains its high character, and shows that in this respect we are not falling behind The Society is greatly indebted to the Editorial Committee and to Dr. Sykes for their devoted services. X number of interesting departmental and other reports have been published during the past twelve months, and have received considerable notice in the public press.Attention has thus been drawn in a special manner to the workiug of the Sale of Food and Drugs Acts, and we now hope for a growing education of public opinion and a desire for improvement. How great the need for such improvement is, is well described in articles in Nature of December 24 and 31, 1903, pp. 179 and 201. Dis- cussing the Final Report of the Royal Commission on Arsenical Poisoning and the Final Report of the Butter Regulations Committee, along with the general working of the Acts, the writer says: “The Food and Drugs Acts are now upwards of a third of a century old. They have been considered and reconsidered by Parliament at various times, even down to the year 1899, and in the consideration have had to run the gauntlet of much deliberate~obsbruction from faddists, federations, and that class of Free-Fooders which regards any legislative interference with the buying and selling of anything of tha.natura lof food, however bad, as noxious economic heresy, and a restriction of the free play of competition.That the Acta contain compromises,74 THE ANALYST, inconsistencies, and anomalies is well known to those who have anything to do with their administration. Nor has the judge-made law by which these anomalies have been interpreted tended to their smoother working; indeed, it has caused them to be absolutely inoperative in certain directions. How imperfect tha Acts are i s strikingly exemplified in the two papers before us.” In the second article the writer points out how Section 3 of the 1875 Act ‘( is so worded that it is almost impossible to obtain convictions under it ” for adulteration with substances injurious to health, which involve heavy penalties.The local authorities, therefore, almost invariably proceed under Section 6, for which the penalty exacted is often trivial. He also points out that, in the interests of revenue, prompt action can and has been taken, while, in the interests of .public health, much mischief may be done before any steps can be taken. A very full abstract of the Final Report of the Royal Commission on Arsenical Poisoning appears in the February number of the Journal. Some of the recommenda- tions made at the end of the Report had already been made by our Council before the passing of the Act of 1899, and one, relating to the association of intermediate vendors, importers, or manufacturers with the retailer in one prosecution, in cases of warranty, was recommended by Mr.Allen in his paper read before this Society last year on May 6. The adoption of the recommendations of the Cornmimion, or of the alternatives proposed by Dr. Thorpe, would tend to remove some of the existing defects pointed out by Mr. Allen in his paper. Amongst other defects still to be dealt with is that arising from the imperfect sealing of samples taken under the Sale of Food and Drugs Acts. With a view to further steps being initiated, your Council earnestly request members who can state cases of supposed tampering with samples to communicate’ with the secretaries, and circulars have been sent asking for this inf ormst ion.Another defect arises from the definition of the word ‘‘ article,” used throughout the Sale of Food and Drugs Acts, by Mr. Justice Ridley in the case of Mason v. Cowdary (2 Q.B.D., 1900, 419). Mr. Justice Ridley adopts the strict etymological meaning of the word ( ( article ’I as “ a small part,” and ignores the derived meaning of the word given in most dictionaries as “ a particular commodity”-not in relation to quantity, as used by people in business in everyday life. By the above decision each package, bottle, etc., however small, is an “article,” and must be divided as the Acts require ; while the statements of persons without of3icial or other responsibility have been accepted as enabling a magistrate to decide as to how minute a, quantity a, Public Analyst should be bound to make an analysis of.An analysis of a suspected sample is a cross-examination. If penal consequences arise, each analyst should decide for himself the extent of that examination, acting, of course, within reasonable limits, just as a barrister has reasonable scope and uses his own discretion in cross- examinations. The Committee on Butter Regulations, appointed in July, 1901, have now made their Final Report. They were asked ‘‘ to inquire and report as to what regulations, if any, may with advantage be made under Seotion 4 of the sale of Food and Drugs Act, 1899, for determining what deficiency in any of the norm&& constituents of butter, or what addition of extraneous matter or propertion of water, in any sample of butferTHE ANALYST.76 shall, for the purposes of the Sale of Food and Drugs Acts, raise a presumption, until the contrary is proved, that the butter is not genuine.” In 1902 they issued an interim report, and the Board of Agriculture published regulations respecting the proportion of water that should .not be exceeded in butter. This limit, which had been approved of by this Society, worked well in practice, but failed to check the sale where a higher proportion of water had been declared before purchaae, or a special name given to the material. These and other reasons led the late Mr. Hanbury to introduce eb Bill to regulate the sale of adulterated butter and maxgarine. This was, however, afterwards withdrawn by Mr.Hanbury’s successor, who promised to introduce a Bill into Parliament this year dealing with the same objects. The Butter Regulations Committee have now issued their Final Report dealing with the remainder of the reference submitted to them, and make the following recommendations : 1. That the figure 24 arrived at by the Reichert-Wollny method should be the limit, below which a presumption should be raised that the butter is not genuine. 2. That the use of 10 per cent. of sesame oil in the manufacture of margarine should be made compulsory. 3. That steps be taken to obtain international co-operation. Nos. 2 and 3 were adopted unanimously by the Committee. The recommenda- tion No. 2 is already in force in Germany, in Austria, and in Belgium, and is contem- plated in France.No. 3 was a recommendation of the Dairy Congress held at Bruasels on April 27 and 28, 1902. The recommendation No. 1 was adopted by a majority of the Committee-ten niembers out of fourteen. Many of the countries exporting butter to this country have organized State control over their production, and by international co-operation or agreement to eecure uniformity the value of the control would be greatly increased. Major Craigie, the representative of the Board of Agriculture on the Committee, would support the use of the number 24 as a limit rather than any other number above or below 24, but thinks that before adopting any such limit the exhaustive inquiry advised by the Committee in paragraph 24 of the Report should be made and concluded. He strongly supports the claim made for a “special inquiry into the numerous factors, other than the addition of foreign fat, which affect the normal proportions of the volatile acids in genuine butter made within the United Kingdom.” Two of the other dissentients support the claim for further inquiry, and one of these, with one other, prefers the number 23 Reichert-Wollny to 24.Thus, thirteen out of fourteen members support the adoption of a limit of some kind. The Council of your Society and some of its members who have special experience in this subject recommended, through their representatives, a course practically agreeing with that adviped by Major Craigie. They did this after collating the replies received from many Public Analysts, and these revealed much diversity of opinion on the subject.No doubt to have a definite limit (even if a low one) secures uniformity, and especially so when it is ~oupled with a, standard method. The objections are : Is it76 THE ANALYST. wise to impose a limit until after the exhaustive inquirfrecommended 3 Would the adoption of this limit and standard method tend to check the constant search for improved methods of analysis? I t is certain that the application of scientific discovery to manufacturing industry will be continued, and may at any time render a standard method useless. The inquiries made up to the present relate chiefly to foreign butters. They show that many of the conditions affecting the proportion of the volatile acid8 in butter are, as regards the cows, the same as those which affect the quality of milk: 1.Exposure of the animals to cold, especially in northern countries, as is shown in butters produced in the late autumn. 2. Insufficient nourishment from scanty or improper food. 3. The period of lactation-the volatile acids are highest soon after calving. 4. The breed and the idiosyncrasy of the cow. I n addition to these, I suggest one other: the length of time between the milkings, as it is well known that the fat in milk diminishes if retained in the udder beyond a certain time. Evidently some absorption of fat from the milk takes place, and it is a matter for inquiry whether the absorption is a selective one. Probably this effect is intensified or increased if, _during a ’prolonged interval between the milkings, the animal is insufficiently fed or unduly exposed to cold.It is also a matter for physiological inqulry as to whether these abnormal milks and butters are of the same dietetic value as normal milks and butters. The natural food of very young animals is that best suited to their powers of digestion. Putting in place of the young, those of weak digestive powers (and many town-dwellers following sedentary occupations are of this class), normal milk and butter would appear to be best adapted for their nourishment. I n very cold countries during the winter season the digestive and assimilative powers for fatty substances of all kinds seem to be greatly increased. This suggests the query, Is not the milk, and consequently the butter, specially adapted for the Eood of animals living in those climates? At present it is found that the composition of butter from one country may differ materially from the average supplied by another country.A Reichert-Wdny number applicable to all must be a lower minimum than would be necessary if limits were specified for each country. The general average of butters supplied in this country, including both home and foreign production, gives, according to Mr. Hehner, a Reichert-Wollny number of 29. In the Annual Report issued by the Intelligence Division of the Board of Agriculture for the year 1902 there is published a paper by Dr. Thorpe “On the Nature of Butter-fat, and on the Causes affecting its Character.” To those who wish for a concise summary of our present knowledge on the butter from different countries, on the tests for its purity, on the influence of different foods on butter, and on the causes of the flavour and rancidity of butter, I commend this paper.The Minister of Agriculture has promised to bring in a Bill, during this Session of Parlia- ment, dealing with the regulations affecting the sale of butter, etc. Two very important volumes have been recently published by the Local Govern- ment Board as supplements to the Reports of the Medical Officer of the Board forTHE ANALYST. 77 1901 and 1902 6‘ On Lead Poisoning and Water-Supplies.” To all those who live in districts supplied with soft water, or have to do with the analysis of soft waters, these volumes are worthy of careful study. From investigations made at Sheffield seventeen years ago, Dr. Power con- cluded that a, chief factor in causing acidity in moorland waters was the action of certain bacteria on peaty soils in the presence of moisture. This view is now fully confirmed by the exhaustive obsemations and experiments carried out by Dr.Houston. The first volume, issued last year, contains very full descriptions of the various water-supplies and moorland gathering grounds of the chief towns in the West Riding of Yorkshire and the adjacent parts of Lancashire, copiously illustrated with maps and diagrams. Numerous analyses are given, and also ample data relating to the surveys of the gathering grounds made during the year 1891 and onwards. The second volume, just issued, discusses the question of plumbo-solvency in all its bearings ; the causes of the acidity of moorland waters ; gives the results of many thousands of laboratory experiments, both chemical and bacteriological, and is fully illustrated.In the conclusions at the end of the second report the question of standards is discussed ; Dr. Houston, however, prefers not to give a limit for the amount of lead in drinking water. The different susceptibility of different individuals to the influence of lead, the divergent views expressed by different authorities as to what quantity is to be considered a poisonous dose when taken from day to day for an indefinite period, and the cumulative character of the poison, are considerations of too grave a nature to allow of any dogmatic statement being made.” The treatment of acid moorland waters with silica in any form does l t not leave them in a safe condition as regards corrosion.Sodium carbonate in exact amount is one of the best remedial agents.” These reports and papers show the activity of these Government departments? and they form the best defence for their continued existence. Similarly, the amount and quality of the work done in our Society, through its members, must always constitute its chief claim to existence, and from the beginning we have welcomed into our midst every analyst, oiiicial or non-official, likely to contribute valuable papers; indeed, but for this, the sustaining of the Journal might at times have been doubtful. In order to strengthen our Society, it would be well in the future to try to promote a, greater community of feeling, or collective cohesion, among the members, especially the country members. I n this respect I think it was a distinct loss that the country meetings were given up. The town members meet frequently, and the Society’s meetings serve as a sort of minor club to them; but country members, living at a distance, can rarely share in this advantage. If the analysts in one part of the country could meet quarterly, or even half-yearly, to discuss matters of common interest, I think we might have an accession of new members. We have had in the North a, small association of this kind for some time, and, judging by the attendance and feeling shown by the members, they appreciate greatly the advantage of these local meetings. Some of our most successful societies owe much78 THE ANALYST. of their success to having local centres of life-in other words, local meetings and sections. I commend this proposal to you for consideration, and now beg to thank you for the patience and courtesy with which you have listened to this address. In conclusion, I heartily thank you all for doing me the honour to ask me to occupy this chair at your meetings. It has been to me a pleasant and a willing service, though not always as perfectly performed as I could have wished. I have been constantly helped by my predecessors and other members of the Council, and especially by your untiring ‘Secretaries, Messrs. Bevan and Chapman.

ISSN:0003-2654    

DOI:10.1039/AN9042900070

出版商:RSC    

年代:1904

数据来源: RSC

摘要:

78 THE ANALYST. NOTE ON THE ESTIMATION OF ALDEHYDES AND KETONES IN ESSENTIAL OILS AND ALLIED SUBSTANCES. By HERBERT E. BURUESS. (Read at the Meeting, December 2, 1903.) THE importance for the analyst to be able to determine with a certain degree of accuracy any one, or preferably the chief, odour-bearing constituent of essential oils is so well recognised by those whose work principally lies in this direction that apologies are hardly necessary for bringing the present communication before the Society. The estimation of aldehydes and ketones in essential oils has always been attended with considerable difficulty, owing to many of the aldehydes themselves not being stable with the reagent used, and breaking down into various complex bodies which are themselves soluble in the reagent; and in some cases the other con- stituents of an oil are soluble to a considerable extent in the reagent used, thus making the percentage too high.I n other cases, moreover, there is formed with the reagent a solid compound which obscures the meniscus to such an extent as to make the reading unreliable. The above remarks apply only to methods of direct absorption-ie., to the methods generally employed. The various methods which have been suggested and adopted are as follows : ABSORPTION PROCESSES. 1. By treatment of the substance with a strong solution of bisulphite of soda or potash. The directions for carrying out this process as prescribed in the various text- books are as diverse as they are numerous, but the general consensus of opinion seems to indicate a strongly acid solution, and in some cases the presence of acetic acid; others, however, advise the use of alkalies, such as sodium carbonate.In considering these methods, it must, of course, be borne in mind that some are well suited to the preparation of the aldehydes or ketones in a state of purity, whilst others are better adapted for their estimation. The latter is the question which the present communication more particultwly deals with. The change which takes place with bisulphite of soda or potash is indicated by the following general equation : RCHO + NaHSO, = RCH<$!&asTHE ANALYST. 79 2. By a condensation product formed with cyanacetic acid in the presence of potassium hydroxide. The reaction that takes place for aldehydes is as follows : RCHO + CH,CN.COOH = R C H : C < ~ : ~ ~ + H,O.3. By shaking the oil with a saturated solution of sodium salicylate. There seems to be evidence of the formation of a weak molecular compound, and with cinnamic aldehyde well-defined crystals have been obtained which give on analysis : NO. Found. Theoretical. 7. Sodium ... ... ... 7.3 I . . 7.9 11. Sodium salicylate . . . ... 53-5 ... 54.8 4. Titratwn Method- By treating aldehydes or ketones with an alcoholic solution of hydroxylamine-hydrochloride, when oximea are formed, advantage being taken of the fact that the unused hydroxylamine may be easily titrated back. The reaction is shown in the following equation : RCHO + H,NOH = RCH.NOH + H,O. 5. Another Xethod, recently suggested by Hanus for Cinnamic Aldehyde.--By treatment with an aqueous solution of semioxamazide, when a crystalline semioxama- zone is formed, which is filtered off, dried, and weighed.6. The method to which particular attention is now directed, and which gives accurate results with nearly all aldehydes and ketones generally met with, is carried out by heating the oil containing aldehydes or ketones with a neutral saturated solution of sodium sulphite, a soluble sulphonate being formed. In the case of citral the following reaction takes place : C,II,,CHO + 2Na,SO, + 2H,O = C,H,7(NaS03),CH*OH~S03*Na + 3NaOH. Advantage is taken of the fact that an alkali is quantitatively liberated, and may, by adding an indicator such as phenolphthalein, bs used to determine the end of the reaction. The details for using the first three methods can be found in various memoirs, and a description of the same as particularly applied to the estimation of citral is given in the Journal of 8. C.I., December, 1901. Since that date the sulphitemethod has been further investigated, and found to apply equally well to most of the essential oils containing either aldehydes or ketones. The objections to the use of methods Nos. 1, 2, 3, 4, and 5, are : 1. The very long time required for shaking ; the difflculty of determining when all the aldehydes are combined; the impossibility of reading the meniscus with accuracy, owing to the insoluble crystalline mass, often accompanied with resinous bodies, floating at the division of the liquids, Dr. Bert4 states that by using the potassium salt he gets good results with citral in lemon oil, and can obtain 7 to 7-5 per cent.2. This method invariably gives too high results, especially with oils containing high percentages; no clear meniscus is formed. 3. OiIs containing different percentages of aldehydes and ketones require different treatment with regard to the quantity of hydroxylamine and bicarbonate80 THE ANALYST. of soda required, and no definite instructions for the use of the process can be prescribed which will apply to all oils. Ricar- Mol. Subs tame . T:$F bona te Bicar - Soda. bonate. Benzaldehyde . . . 1.034 9 ) ... 1.039 9 9 ... 1-037 7 ) ... 0.935 9 , ... 0.900 Carvone ... 1.411 9 s ... 1.410 ?, ... 1.408 ? ? ... 1-346 Caraway oil ... 2.135 Citronella1 . . . 1.276 ?, ... 1.308 ...1.320 Cumkc aldehyde 1.442 7 1 1.459 0.4 0.8 0.8 1.1 1.0 0-8 0.8 1.1 1.0 1.0 0.35 0.7 1.1 0.4 0.8 0-5 1.0 1.0 1.5 1.5 1.0 1 *o 1.3 1.3 0.5 1.0 1.5 0 -5 1.0 - Hydros- ylamine Taken =c.c. -! 1D NaOH. 124 124 378 378 150 378 378 378 150 150 124 124 378 124 124 Hydrox- ylamine Used. 91 94 85 79 75 90 83 89 80 78 40 61 50 91 93 Time of Heating (Minutes). 30 30 60 30 60 30 60 30 60 60 30 30 30 30 30 Per- centage. 93.3 95.9 86.9 89.6 88.3 95.7 889 94.8 89-2 54.8 48.3 71.8 58.3 93.4 94.3 4. The objection to this method lies in the fact that not only aldehydes, but nearly all oxygenated constituents, are absorbed by this reagent; but it will give, under definite conditions, figures of considerable value in essential oils containing mixtures of alcohol, esters, and aldehydes with terpenes, which will apply to all cases.Estimation in Esseiztial Oils by the Sulphite Method.-With regard to the deter- mination of aldehydes and ketones, essential oils may be conveniently divided into two classes-those in which the estimation is made directly on the oil, and those in which the amount is too small to allow of direct estimation, but where preliminary concentration is necessary, such as citron, lime, lemon, and orange oils. In cases in which direct estimation on the oil is possible, the procedure is as follows : Five C.C. of the oil are introduced into a 200-C.C. flask, having a neck graduated to 5 C.C. in &ths of a c.c., with a, side tubulus reaching to the bottom of the flask for introducing the oil, reagents, and water. To the measured oil is added a saturated solution of neutral sulphite of soda and 2 drops of ordinary phenolphthalein solution ; it is then placed in a, water-bath and thoroughly shaken, when a, red colour is quickly pro- duced.I t is carefully neutralized with 1 to 10 solution of acetic acid until, after the addition of a, few drops of acid, no further colour is produced. The oil is then run up into the graduated neck, and when cold carefully read. The difference between 5 C.C. and the reading will give the amount absorbed, and this multiplied by 20 the percent age. The following are results obtained by this process ; in each case the substance has been further carefully examined, both chemically and physically, and in all cases represents a pure or commercially pure article :THE ANALYST.81 ALDEHYDES, KETONES, AND OILS ON WHICH A DIRECT DETERMINATION CAN BE MADE. Oil of Almonds (Bitter).-The method answers well in the case of this oil. BenzaZdehyde.- The chief constituent of oil of almonds is completely absorbed, even in the cold, giving a clear solution. Experiments made on a mixture of pure benzaldehyde and limonene which had been carefully redistilled over sodium several times gave theoretical results. Reaction seems to take place according to the following equation : C,H,CHO + Na,SO, + H,O. = c6HscH*(g&a + NaOH. I06 The following data &re confirmatory : Took 5-3 grammes benzaldehyde and 12.6 grammes of crystallized sodium sulphite (theoretical amount) aqd titrated with N acid. Required : Exp. NaOH. Calc.1 . . . 44-2 C.C. =: 1-8 grammes . .. 2.0 2 ... 45.6 ,, =1.82 ,, ... 2.0 Well-defined crystals are formed in the neutralized solution on standing. On examina- tion they proved to be identical with the ordinary bisulphite addition product, as the aldehyde is again liberated by the addition of acids or alkalies. Anisal.-Gives theoretical results and a clear solution. Mixtures of pure aldehyde and limonene gave theoretical results. Caraway Oil. -The method will be found very useful for this oil, the only convenient test for the valuation of the oil up to the present being its specific gravity, from which is calculated the percentage of carvone present, on the assumption that the oil only consists of limonene and carvone. But this is not sufficient to detect adulteration. Some recent oils gave by the method 55 and 57 per cent.Carvone, as may be inferred from the above, is readily absorbed by this reagent, giving theoretical results. A similar reaction to that which occurs in the case of benzaldehyde probably takes place with this ketone : C,H,,CO + Na2S0, + H20. 150 Took 7.5 grammes carvone and titrated with N acid. Calculated 2.0 gremmes NaOH. required. cinnamon oil (genuine), 68, 74, and 72 per cent. Required : 49.4 C.C. = 1.98. Cassia a?zd cinnamon oiZs both give good results. Large amount of phenolphthalein For cassia oil some figures recently obtained are 80 and 85 per cent. ; and for82 THE ANALYST. Cinnamic aldehyde, the chief constituent of the above oils, also gives theoretical results. The following equation probably shows the reaction that her6 takes place : C,H,.CH:CHCHO + 2Na,SO, + 2H,O. 132 = C,H,.CHSO,Na.CHOH.CE~~~Ns + 2NaOH.Took 3.3 grammes of aldehyde. Required 46.5 C.C. N acid=1.86 NaOH. Cd- culated 2.0 grammes. The same reaction probably applies in the case of citral and citronella1 and all olefinic aldehydes. Citra1.-As has been shown elsewhere, the method answers well, giving theoretical results. Citronellal forms a milky solution, and at first is very frothy. Consequently, care must be taken that none is lost through this cause. considerable time and heating to complete the reaction, but gives good results. genuine oil gave 24 per cent. cumic aldehyde. of acetic acid goes into a clear solution. Litmus shduld be used. as the carvone may be estimated with accuracy.cent. sharply-defined meniscus. It has been shown by Parry that acetone is sometimes added to make the oil pass the solubility test. This would also show as aldehyde by the absorption method. Shaking the oil with water, or determination of its refrac- tive index, will, however, at once indicate oils thus sophisticated. Oil of Pennyroyal.-With this oil phenolphthalein does not act well as an indicator. Litmus is better. Pu leg one .-- Oil of Spearmint.-The method is valuable in the case of these oils and works well, giving a clear solution. Oils of Tansy, Thuja, and Wormwood.-The method is useless for these oils, for the reason that thujone, the active constituent of these oils, does not form a com- pound with the reagent. Nonyl and Decyl Aldehydes.-Considerable time and heating are required to com- plete the reaction with these substances, but good results may be obtained.Oils in which a Direct Estimation of Aldehydes and Ketones cannot be made.--In this class there are only four of importance-viz., citron or cedrat, lemon, hand- pressed lime, and orange oils-and it will be convenient to consider the estimation of citral in lemon oil first, as the same method and remarks will apply in many respects to the other three oils. Lemon Oil.-As this oil contains only a small percentage of total aldehydes, and consists chiefly of the inodorous hydrocarbon limonene, it is necessary to care- fully fractionate out the hydrocarbons, and, while doing this, the analyst may come to a more definite knowledge of the genuineness of the oil if the following procedure be adopted.The reaction takes Oil of Cumin.-Litmus solution will be found a better indicator for this oil. A Cumic aldehyde at first forms a solid compound, but on heating with the addition Oil of DiZL-In the case of this oil the method will be found extremely useful, A recent distillation gave 50 per Oil of Lemongrass.-The method with this oil works remarkably well, giving A recent oil gave 16 per cent. pulegone. Genuine oils give about 62'per cent. carvone.THE ANALYST. 83 The method, as particularly applied to lemon oil, was first suggested in a paper read before the Society of Chemical Industry in December, 1901, and since that time has been further investigated as a general method for other oils of a similar type, and for convenience is again described. Having first determined the specific gravity at 15' C., the rotation in a 100-milli- metre tube by sodium light, and the refractive index at 20' C., the oil is next distilled, and this, if carried out carefully, will shorn any adulteration.One hundred C.C. of the oil to be examined are put into a distilling-flask having three bulbs blown in the neck, and fitted with cork and thermometer. This is connected to a condenser with a suitable receiver, having two vessels graduated at 10 C.C. and 80 C.C. respectively. A Bruhl's apparatus answers the purpose very welL The whole is exhausted, and a pressure of not more than 15 m.m. should be obtained. The flask is now gently heated by means of an oil-bath, and 10 C.C. distilled into the first tube.The next vessel is then put into position and the distillation continued until 80 C.C. have distilled over. The pressure is now relieved, and the residual oil in the flask distilled over with steam. Then the differences in rotation and refractive index of fraction 1 and those of the original oil will indicate added turpentine; fraction 2, lemon terpenes; fraction 3, the total amount of oxygenated constituents-ie., terpeneless oil and the amount of aldehydes. The aldehyde should be estimated on this fraction after the above two constants have been taken in exactly the same manner as previously described. For example, supposing 7 C.C. of oil were obtained for the third fraction, and that, of the 5 c.c., 2.1 C.C. were absorbed in the aldehyde determination, the percentage of citral in the original oil would be 2'1 2o =%9 per cent.A few remarks here as to the per- centage of citral contained in lemon oil may not be out of place, especially as the subject is one that has recently been the cause of dispute among several essential- oil analysts. The percentage given by this method is somewhere about 3 per cent. for genuine oils, whereas, up to some four years ago, 7 to 7.5 per cent. was the only figure that could be recognised as compatible with a genuine oil. This higher percentage is still maintained by some analysts, both English and Italian, although there is no known method that will give directly or indirectly a figure anywhere approaching this percentage. The facts admitted on all sides are : 1. That a genuine oil does not yield more than from 5 to 6 per cent.of con- centrated, i.e., terpeneless, oil. 2. The oxygenated constituents in the 90 per cent. or so of terpenes distilled are less than 1 per cent. 3. A concentrated oil never contains more than 50 per cent. of aldehydes, the average being 46 per cent. On the face of these facts, admitted by all experts, it seems inconceivable that any analyst should maintain a 7 per cent. standard, as, taking an oil yielding at the highest 6 per cent. of concentrated oil, only half or 3 per cent. of this would be of an aldehydic nature. Such guaranteed 7 per cent. oils must, of necessity, be very misleading to con- The quantity so obtained should be carefully noted.84 THE ANALYST. sumers and manufacturers, and tend to place the analysts in a very false position, as on such certificate a manufacturer of concentrated oils would expect a yield of 12 per cent.at least of terpeneless oil ; but, as above mentioned, this is not the case. Zhnd-pressed Lime Oil. -The method as above described for lemon Oil8 is equally useful for the determination of citral in this oil, which should contain about 8 per cent. of this constituent. This distillation method would at once show the addition of lemon or orange oil. Citron or Cedrut Oil.-Consists chiefly of citral and limonene (vide ANALYST, October, 1901). The same method of distillation may be used, A genuine oil should contain about 4 per cent. Oil of Orange.-This oil consists chiefly of limonene and a small quantity of decylic aldehyde.The distillation method is useful in detecting adulteration with cheaper oils of the citrus series. The rotation of the first 10 C.C. should always be higher than that of the original oil, and the aldehydes may be determined on the third fraction. A typical sweet orange oil gives about 0.75 to 1 per cent. In conclusion, I wish to express my thanks to the proprietors of the London Essence Co., in whose laboratories this work has been carried out, for time and material placed at my disposal, and for valuable analytical work and suggestions by Mr. T. H. Page, B.Sc. DISCUSSION. The PRESIDENT (Mr. Fairley ) having invited discussion, MR. ERNEST J. PARRY said that, of the questions dealt with in this paper, probably the most important was that of the percentage of citral in lemon oil.The lemon-oil industry was one involving very large commercial interests. Many tons of lemon oil which wag guaranteed by certain analysts in Messina and in London to contain 7 per cent. of citral were annually imported into this country, but it had never been found possible-although many representations had been made-to obtain an official statement of the methods of analysis yielding the results upon which such guarantees were based. He desired to draw special attention to this, since in his own experience-and, he believed, in that of other analysts also-trouble repeatedly arose in regard to samples of lemon oil, because, although 7 or 74 per cent. of citral was guaranteed, it was found inipossible to return more than from 3 to 34 per cent. When Mr. Burgess and Mr.Child some two years previously communicated to the Society of Chemical Industry their paper on the subject, he had been inclined some- what strongly to oppose their views as regards the percentage of citral in lemon oil, and had considered the true percentage to be much higher than they believed it to be. At that time he was using a process involving distillation of the oil under reduced pressure and determination of the citral in the last 10 or 12 per cent. by absorption with cyanacetic acid. Mr. Burgess had hinted that the results yielded by the cyana- cetic acid method were too high, but Professor Tiemann, Messrs. Schimmel, and he (Mr. Parry) himself had found that the process gave very accurate results under certain conditions. He found, however, that unless the cyanacetic acid used was absolutely fresh very erroneous results might be obtained, owing, probably, to theTHE ANALYST.85 cyanacetic acid undergoing some molecular change on keeping; and to that cause he attributed the fact that the results he had then obtained-namely, from 5 to 6 per cent.-were too high. A large amount of published work had shown 7 per cent, to be an impossible figure. Mr. Burgess had examined probably some thousands of samples, and he (Mr. Parry) had examined a very large number in absolutely ident.ica1 apparatus with that now described, and he could confirm Mr. Burgesds results in every respect. Turning to other matters referred to in the paper, he had found that, in the estimation of cinnamic aldehyde in cassia, oil by the bisulphite process, reading was always rendered difficult by the collection of resinous matters in a layer beneath the meniscus.This was not of much importance in practice, seeing that the amount absorbed was at least 70 or 75 per cent., but he would like to hear whether by the use of the monosulphite the presence of the resinous layer would be done away with. Absorption processes generally, from a theoretical point of view, were incorrect, for, apart from the actual chemical reaction, it was necessary to take into account the equilibrium of the solvents. For instance, the same sample of clove oil would yield different results with different strengths of caustic potash, and in no case would there be an absolute absorption of the eugenol with the whole of the caryophyllene left floating at the top, for it was always possible to extract with ether from the soap solution a, further quantity of the hydrocarbon which had dissolved in it.Errors from such causes as this were most accentuated in processes like that of Bert&, in which the terpenes were not first eliminated by distillation, but if the terpenes could be eliminated free from citral the errors due to secondary causes were so slight as to be of little importance. He agreed with Mr. Burgess that the maximum amount of citral lost in the terpenes was 0.2 per cent., and an allowance for a loss of that amount was always made in his own analyses. It was, moreover, an established fact that no ordinary lemon oil could be made to yield more than about 5 per cent.of terpeneless oil, and not much more than half of this was citral; so that, for there to be 7 per cent. of citral in the original oil, at least 4 per cent. must be lost in the terpenes-which had never yet been shown to be the case. Jf such a loss really did occur, there would be no difficulty at all in detecting it, for in the case of orange oil, althoiigh the amount of citral present was very small indeed, he had been able, after concentration, to separate well- defined cry st als of citryl-P-naphtocinchoninic acid having a sharp melting-point. Consequently it would be quite possible to detect the presence in the terpenes of well under 1 per cent. of citral. He had rarely met with any pure lemon oil that conformed to the British Pharmacopmia requirement that the rotation of the first 10 per cent.distilled should not differ by more than 2 O from the rotation of the original oil, and, in his opinion, any sample fulfilling that condition must usually be heavily adulterated. Mr. J. F. CHILD said that, when this distillation method of the estimation of citral in lemon oil had been originally brought before the Society of Chemical Industry by Mr. Burgess and himself, the figures given for the citral content of the third fraction were worked back to give the percentage of citral in the oil itself, but it was not sug- gested that this was absolutely correct, but only an indication of the probable altbount. From lemongrass oil practically the whole of the citrrtl could be fractionated, but in He understood that this would be the case.86 THE ANALYST.the case of lemon oil this W ~ S not possible; in fact, it was impossible to obtain a fraction containing more than 78 per cent., for some decomposition always occurred. So in the present case also there must be some small loss due to decomposition-not much, perhaps, but certainly more than Mr. Parry or Mr. Burgess had allowed for. He thought it amounted probably to about 8 per cent. Mr. T. H. PAGE said that one of the most satisfactory results they had obtained with this process had been the fractionation of a large quantity of terpeneless lemon oil and the determination of the percentage of citral by the sulphite process in each of the fractions. The fractions were mall, so that the citral content, except in the first and last few, was nearly the same.In practically all cases consistent results were obtained. In a few cases there were discrepancies of 1 or 2 per cent., but this could only be expected with an absorption process ; but this was certainly better than with any other he had used. Moreover, in the case of mixtures containing known quantities of citral, the results obtained completely bore out the calculated proportions. Mr. CHAPMAN said that the new and really important matter brought forward in this paper was the applicetion of the sulphite method, which had been described some time ago by Mr. Burgess in reference to the estimation of citral in lemon oil, to a large number of other essential oils containing aldehydes and ketones. The process certainly marked a very great improvement on the older bisulphite extraction method, as the reaction appeared to be fairly quantitative, and to be capable of measurement by the formation of alkali, which marked the completion.In the acid sulphite pro- cess, in which one simply shook a measured volume of the oil with a saturated solution of sodium bisulphite, it was necessary to experiment with known mixtures, and to assume that after a certain number of shakings and after heating to a certain temperature the extraction was complete. There was one point which Mr. Burgess had not alluded to--namely, the chief reason given by Dr. Bert6 for the substitution of the potassium for the sodium salt, which he (Mr. Chapman) believed to be that a clear solution of all the aldehyde compounds was obtained, and consequently there was no troubled meniscus, but quite a sharp line of demarcation between the two liquids in the measuring tube.He had not himself, however, been able to test this point, and therefore did not know whether the claim was a correct one. The situa- tion at present existing with regard to the determination of citral in lemon oil was certainly one which he thought was almost unparalleled in the history of analytical chemistry. A number of chemists who were interested in the analysis of essential oils had made very careful examinations of lemon oil and of solutions of citral in redistilled hydrocarbons by several methods, and the results for genuine oil of lemon had invariably fallen very far short of 7 per cent. of citral; while, as Mr. Burgess had mentioned, manufacturers working on a large scale had found themselves unable to obtain anything like 7 per cent.of citral from the oil. Nevertheless, as Mr. Parry had remarked, it was agreed that the hydrocarbons obtained were practically free from citral. Where, then, did the remainder of the citral go to? He certainly thought that those chemists who maintained that 7 per cent. was a correct proportion ought to state in detail the processes by which they arrived at their results. No such statement, however, had hitherto been made, with the single exception of a brief noteTHE ANALYST. 87 recently published by MU. Bert6 and Soldaini. Very large commercial interests were involved, and those chemists who were unable to obtain such high results as 7 per cent.were placed in a somewhat unpleasant position. He must say that he could not see that the particular apparatus now shown possessed any advantage over the one which had been previously described before the Society by himself and Mr. Burgess. Among the advantages which he thought that apparatus possessed over Dr. BertB’s was the small tube at the bottom, which enabled fresh liquid to be run in and the exhausted liquid to be run off, the whole contents of the flask being thus maintained under far more complete control than was possible in a long tubu- lated flask. Then, again, 25 C.C. was for obvious reasons a far better quantity to work on than the 5 C.C. used by Dr. Bert& In connection with the vduable distillation process for which Mr. Burgess and Mr. Child were responsible, he had carried out side by side duplicate experiments on the same oil, as far as possible at the same rate of distillation, and yet had met with pretty wide differences in the optical properties of the corresponding fractions. Possibly Mr.Burgess, with his greater experience, might be able to get more definite results, but his own experience had been that it was unwise to draw too definite conclusions from the figures obtained for tbe separate fractions. Mr. ALLEN said that it used to be considered that aldehydes formed with bisulphites definite substances which were constant in character. These bodies, however, were now known to be sometimes very complex, two or even three different compounds being capable of being produced from the same aldehyde, according to the sulphite used, and apparently according to the strength of the sulphite solution.All these were circumstances which tended to shake one’s faith in absorption- processes as ordinarily carried out. He was glad to think that Mr. Burgess had been able to ascertain the composition of the products formed from the amount of alkali set free in the reaction. Personally, he had a very limited confidence in the composition of commercial sulphites, for so-called sulphites of the alkali-metals were sometimes largely sulphates, and contained very variable amounts of scCual sulphite. Perhaps bisulphites were better. The potassium metabisulphite was probably the most constant product. He would, however, like to have Mr.’Burgess’s assurance that he knew the exact composition of the sulphite used, because such knowledge would add very much to the ease with which other chemists could repeat his experiments.The whole subject of essential oils was one of great interest, and when experts differed to such an extent as was sometimes the case it was quite time that the reasom for such differences were fully known. He had no sympathy with chemiets who were not prepared to explain their processes to others, and who pre- ferred, although they maintained the accuracy of their results, to keep their processes secret. Mr. BURUESS, in reply, said that the cyanacetic acid process was a somewhat complicated one, and he was glad to know that Mr. Parry had succeeded in obtaining good results with it. He (Mr. Burgess) thought that the reason for the production of a clear meniscus in cassia oil when sulphite was used was simply the fact that the resinous bodies were then contained in the unabsorbed portion of the oil, whereas when bisulphite was used they formed a sort of emulsion with the crystals of the88 THE ANALYST.double compound which always remain undissolved. It was quite true, &B Mr. Child had said, that there might be a loss of citral during fraotionation, but even if it were as much as 8 per cent,, that would not bring the results materially closer to the 74 per cent. which was maintained to be present. There could be no doubt that some loss did occur in that way, although the point had never been brought forward until Mr. Child had mentioned it on this occasion. Although this discussion had rather turned upon the question of citral in lemon oil, the object of the present paper was, as Mr. Chapman had said, really to show that the method was applicable to many other substances. With regard to the apparatus, it had been stated by Dr. Bert6 and by others that, if the particular apparatus in question were used with potassium bisulphite, 74 per cent. of citral could be obtained. He (Mr. Burgess), however, and others also, had not been able to obtain higher results than 44 or 5 per cent., and it must be borne in mind that even here there was oonsiderable amount of solubility of the terpenes in the reagent used. The apparatus devised by Mr. Chapman and himself was certainly for many reasons preferable. In the first place, the multiplication error was reduced to one-fifth of that in Dr. Berte’s process, and it was much easier to get the temperature the same each time-an important point, since these determinations were all made by volume. The small apparatus he had himself devised was merely a modification of the Hirschsohn flask, with a tubulure reaching to the bottom, so that there was no chance of the oil coming up, and water could be let in very gently to raise the meniscus. He htbd found no difficulty in obtaining good crystals of sodium sulphite of composition represented by the formula Na2S0,,7H,O. The metabisulphite could always be obtained of pretty constant composition.

ISSN:0003-2654    

DOI:10.1039/AN9042900078

出版商:RSC    

年代:1904

数据来源: RSC

摘要:

88 THE ANALYST. ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. FOODS AND DRUGS ANALYSIS. The Determination of Glycerin in Wine. J. GI.. Gugliemetti and V. Coppetti. (Ann. de Chim. aqaaZ., 1904, ix., 11, 12.)-The following rapid method is stated to give very accurate results: Fifty C.C. of the wine are thoroughly mixed with 2.5 grammes of animal charcoal and 50 grammes of purified dry sand, and the mixture evaporated to dryness on the water-bath. The residue, after cooling, is pulverized and mixed with 5 grammes of powdered quicklime, and the gray powder heated on the water-bath with 50 C.C. of absolute alcohol (specific gravity 0.796). Tho alcoholic extract is filtered off, and the residue extracted twice more in the same way with successive portions of 25 C.C. of alcohol. The united alcoholic extracts are slowly evaporated on the water-bath to about 5 C.C.The basin is then finally rinsed with 5 G.C. of absolute alcohol, and the washing of the residue finished with 30 C.C. of sulphuric ether (specific gravity 0*720), the washings being added to the alcoholicTHE ANALYST. 89 extract, and the mixture shaken and filtered. The colourless filtrate is collected in a, weighed platinum basin, the tube being washed out twice with 5 C.C. of sulphuric ether, and the washings also passed through the filter. The basin is heated on the water-bath at about 60” to 70” C. for thirty to forty-five minutes, the drying then completed in a desiccator, and the residue of pure glycerin weighed in the covered basin, every precaution being taken to prevent the absorption of water.C. A. M. Determination of other Flours in Wheat Flour. G. Volpino. ( h i t . fh“ Untersuch. tier Nahr. zcnd Genussmittel, 1903, vi., 1089-1095.)-Two methods are described. The first depends on the quantity of gluten obtained from the sample; whilst the second is based upon the fact that foreign flours contain a considerably larger proportion of insoluble proteids, excluding gluten, than does wheat flour. If a mixture of wheat dour with rye, barley, maize, or rice meal be made into a dough, and the latter be well kneaded in a stream of water, a m&ss of gluten is obtained, approximately proportional in quantity to the amount of wheat flour present. For instance, 30 grammes of wheat flour yielded sbouf 8 grammes of gluten. A mixture consisting of 15 grammes of wheat flour and 15 grammes of either rye, barley, maize, or rice meal gave from 4 to 5 grammes of glrzten.The details of the second method are as follows : 30 grammes of the meal are formed into a lump of dough with a little water. The dough is well washed in a stream of water, being during this operation kneaded with the hands. All the wash- water is collected and strained through a piece of linen to remove small particles of gluten. The liquid is then passed through an asbestos filter, and the residue on the filter dried for one hour at 100’ C. The nitrogen is now determined in 2 grammes of this dry residue, and the amount found multiplied by 6 to give the proteide present. Pure wheat flour does not yield more than 0.2 per cent.of insoluble proteids other than gluten, whilst maize meal contains 6-5per cent., barley and rice meals 6.0 per cent., and rye meal 5.0 per cent. of these proteids. w. P. s. The “Dextrins” of Pine-Honey. 0. Haenle and A. Scholz. (Zed. fur U?ztersuch. der Nuhr. und Genussmittel, 1903, vi., 1027-1031.)-The so-called ‘ 6 dextrins ” consist of various bodies which do not readily ferment, and which may therefore be separated by fermenting the other sugars of the honey with yeast. A portion of these ‘‘ dextrins” is insoluble i s 87 per cent. alcohol, and can be precipitated from a dilute alcoholic solution as barium compounds by the addition of barium hydroxide solution. They reduce Fehling’s solution to a slight extent, but are converted by hydrolysis into st mixture containing about 30 per cent.of reducing carbohydrates. The dextrins ” themselves are strongly dextro-rotary to polarized light. w. P. s. Cocoanut Oil in Margarine. E. W. T. Jones. Chem. News, 1903, lxxxviii., 317.)-Attention is drawn to the evident occurrence of cocoanut oil in margarine. The fat of this oil has a high specific gravity, a low Valenta degree, and a refraction90 THE ANALYST. corresponding with that of genuine butter-fat ; hence -the butyro-refractometer is useless for detecting this form of admixture. Two samples examined gave the following figures : Specific gravity at 100" F. . . . ... ... 911.3 909.7 Reichert-Wollny number (5 grammes) . . . 4.3 4.5 Valenta test ... ... ... ... ... 74O c. 79" c. Refractometer number at 30" C. ... ...50.0 47.5 w. P. s. The Formation of Viridinic Acid from Caffeo-Tannic Acid. A Nestler. Zeit. fiir Untersuch, der Nahr. uud Genzusmittel, 1903, vi., 1032-1033.)-0n washing coffee-berries in a dilute solution of sodium carbonate to remove dirt, it was noticed that, after drying the berries in the open air, they became black, greyish-black, or green in colour, This coloration penetrated deeply into the interior of the berries, and was due to the oxidation of caffeo-tannic acid in the presence of alkali, viridinic acid being formed. Experiments were made, which showed that a dilute solution of any of the alkalies or alkaline carbonates produced this change in coffee-berries, and also in an aqueous extract of the latter. Another colour-reaction with coffee-berries is mentioned.On treating a section of a berry with a drop of concentrgted hydrochloric acid, after about thirty minutes a microscopical examination shows that the cell contents are coloured blue. The addition of glycerol changes the colour to bluish-green, then grey-green, and finally grey w. P. s. The Amount of Salicylic Acid in Cherries and Violets. A. Desmoulibre. (Journ. Pharm. Chim., 1904, xix., 121-125.)-Cherries of different origin examined by the author were all found to contain salicylic acid as a normal constituent. The following results were obtained by a colorimetric method of determination applied to a solution of the extracted salicylic acid : English cherries, 0.15 ; French cherries, 0.20; sour cherries, 0.15; black Bourgogne cherries, 0.10; and wild cherries, 0.21 milligramme per kilogramme.Salicylic acid was also detected in the marigold, and also in different members of the VioZace@ family, the amounts ranging from a trace in V. odoruta, etc., to 0.08 to 0.144 per cent. in V. Syrtica, tricoEor, and arvensis. The cultivated variety of V. tricoEor contained less salicylic acid than the wild plant. C. A. M. Determination of the Alcoholic Strength of Tincture and Liniment of Iodine. (Pharm. Journ., 1904, lxxii., 9.)-A convenient quantity of liquid is shaken with an excess of metallic mercury. The reaction is rapid, mercuric iodide being formed, which dissolves in the potassium iodide to a colourless solution, or nearly so, if British Pharmacopoeia spirit has been used. Should methy- lated spirit have been employed, the colour of the solution is dark yellow.After complete chemical change has been effected, a small quantity of sodium hydroxide F. H. Alcock.THE ANALYST. 91 solution is added, and the distillation proceeded with in the usual way. Unless sodium hydroxide be added, traces of merouric iodide always [pass over into the distillate. w. P. s. Determination of Morphine in Opium. P. L. Aslanoglou. (Chem. News, 1903, lxxxviii., 286, 287.)-In this process the morphine is extracted from the opium with water, the alkaloid being then precipitated from the evaporated aqueous extracts, washed with ether, dried and weighed. Ten grammes of the opium are extracted for several hours-twelve hours for the first extraction-with several successive quantities of 250 C.C.of water. The filtered extracts are evaporated, the residue is taken up with 75 C.C. of water, filtered and washed to make 100 C.C. of filtrate. Thirty C.C. of 94 per cent. alcohol are added to the latter, and, after stirring for thirty minutes, 4 C.C. of 10 per cent. ammonia solution. The mixture is set aside for twelve hours, when the precipitate is collected on a tared filter, washed with 50 C.C. of water, drained, and partially dried at 60" C. The filter and morphine are then well washed with ether, and finally dried at 75" C. and weighed. 0.1012 gramme is added to the weight of morphine found in 10 grammes of opium, to correct for solubility of the alkaloid in the quantity of solution and washings used. w. P. s. Determination of Morphine in Opium and Tincture of Opium.E. Dowzard. (Pharm. Jozmn., 1903, lxxi., 909-910.)-The author considers that the British Pharma- copaeia method is clumsy from an analytical point of view, and also objectionable because of the difficulty of obtaining the necessary 104 C.C. of filtrate; he has, there- fore, devised the following method, which is free from these objections, and at the same time requires much less opium. Eight grammes of the powdered opium are treated in a flask with 100 C.C. of water for one hour at a temperature of 80" to 90" C., the flask being closed with an india- rubber stopper and frequently shaken during this time. The contents are then cooled, 3 grammes of slaked lime added, and the mixture well agitated in the closed flask for a further two hours. The whole is now poured on a filter, 51.6 C.C.of the filtrate (equal to 4 grammes of opium) are placed in a corked flask, 5 C.C. of 90 per cent. alcohol, 30 C.C. o€ ether, and 2 grarnmes of ammonium chloride are added, and, after shaking for 30 minutes, allowed to stand for twelve hours. The whole is then filtered, when the morphine remains attached to the filter, which also retains the clear ether, whilst the aqueous portion runs through. After removing the clear ether with a pipette, the filter and its contents are washed with morphinated water until free from chlorides, then once with water, and finally with about 15 C.C. of ether, the latter being poured over the edges of the filter and rern\oved, at the end of a few minutes, with a pipette. Both filter and morphine are exposed to the air for thirty minutes, then broken up in a beaker by the aid of a glass-rod, and gently heated with 20 C.C.of & sulphuric acid solution. After cooling, the solution is titrated with & sodium hydroxide solution, using methyl orange as indicator. Each C.C. of & sulphuric acid solution is equivalent to 0.0283 gramme of anhydrous morphine, 0.05 gramme being added to the weight found, as directed in the British Pharmacopa4a.92 THE ANA&YST. In the case of the tincture, 100 C.C. are evaporated to a volume of 30 c.c., 3 grammes of slaked lime are well mixed with the residue, and the mixture trans- ferred to a, 100 C.C. flask. Water is added up to the mark, any froth being removed by the addition of a drop of ether, and the solution allowed to stand for one hour.After filtration, 50 C.C. of the filtrate (equal to 50 C.C. of the tincture) are operated on as described urlder opium. In this process 80 C.C. of tincture and 3 grammes of slaked lime are diluted to a volume of 85 c.c. The latter should be 81.9 c.c., as 3 grammes of slaked lime, together with extractive carried down with it, displace 1.9 C.C. of water. Tables are given showing percentages of morphine in both opium and the tincture for each 0.1 C.C. of $n sulphuric acid solution used, the range being from 9 to 20 C.C. in tenths of a C.C. An error in the British Pharrnacopceia method is pointed out. w. P. s. A Reaction distinguishing between Heroine and Morphine. Manseau. (Bull. Xoc. Pharm. Bordeaux; through Ann. de ChiwL. anal., 1904, ix., 22.)-0n adding a little heroine to 2 C.C.of a 10 per cent. solution of urotropine in sulphuric acid there is an immediate golden coloration, changing to saffron-yellow, and finally to deep blue. Morphine, under the same conditions, gives a purple coloration, whilst narceine gives a saffron-yellow, and narcotine a golden-yellow. The yellow colour given by heroine is intermediate between the colours given by narceine and narcotine, but any confusion can be prevented by repeating the test, using formaldehyde in place of urotropine. C. A. M. Adulterated Spike Oil. E. J. Parry and C. T. Bennett. (Chem. und Druggist, 1903, Ixiii., 1011.)-Large quantities of adulterated spike oil having appeared on the market during the last few months, most of it having apparently been specidly prepared to pass the ordinary tests to which spike oil is usually subjected, the authors record a few of the adulterants they have met with and the means adopted for their detect ion.The optical rotation of the oil should not exceed +4O. Samples with a rotation over + 5' are very suspicious. The usual solubility test in 70 per cent. alcohol is untrustworthy, but by using six volumes of 65 per cent. alcohol at 15' C. the authors find that, whilst pure oils are soluble, the addition of 5 to 10 per cent. of most adulterants affects this solubility. A fractional distilla$ion reveals practically any adulterant that is likely to be added to spike oil in sufficient quantity to be remunerative. The usual adulterants are turpentine, oil of rosemary of the commonest quality, and safrol. In a sample examined a fraction was obtained, boiling between 230' and 240' C., which had a specific gravity of 0.986, was optically inactive, and had a refractive index of 1.4980.Its odour was marked, and was sufficient to identify it as being chiefly safrol. The percentage of esters and alcohols present gives useful information should oil of rosemary be suspected. w. P. s.THE ANALYST. 93 Adulterated Citronella Oil. E. J. Parry and C. T. Bennett. (Chem. and Druggist, 1903, lxiii., 1061.)-A sample of this oil recently examined was found to contain 20 per cent. of alcohol, which had probably been added to make an already adulterated oil soluble, and thus pass 1 L Schimmel's test." This form of adulteration is readily detected on distilling the oil.w. P. s. Cod-Liver Oil and its Adulterants. E. W. Mann, (Pharm. Jouurn., 1903, lxxi., 840.)-The adulteration of cod-liver oil does not usually consist in adding a, foreign oil to it. Non-genuine oil is more often composed of a mixture of oils obtained from the livers of a whole catch of fish without discrimination-cod, haddock, coalfish, shark, and:others. To ascertain whether these various oils could be distinguished from one another, the author has carried out a number of experi- ments, the results of which are given in the following table. The samples are authentic, in most cases being actually prepared from the fish, under supervision. --- Cod-liver oil, Cod-liver oil, Norwegian .. Newfoundland Cod-liver oil, Japanese .. Whale oil ..Shark oil .. Haddock oil . . Coalfish oil . . Seal oil .. .. Dugong oil . _ Ling oil.. .. Minhaden oil . . Hoi oil .. .. Brusrner oil . . V I A 2 s o c &$ 0.9262 0'9258 0.5252 0'9192 0'9290 0'9318 0.9272 0-9275 0'9203 0.9231 0'9301 09186 0.9222 a -2 f m a 25 -4 147'79 139.25 134'96 92-35 143'50 160'00 139.10 123-40 66.60 122-80 145'80 116'60 130.11 a 4 8 2 .r( - 0.36 0.45 1 '40 2'08 6'09 2.67 1-35 2-79 2.39 0.29 2-50 0'18 0'13 8 F ; 5 nB d Z p g 1S4-1 185.4 186.7 188% 1885 191'2 186.1 194.5 197.5 181.6 186.1 164'7 180.4 7'74 9.87 7-18 7.70 5'46 2 '42 6.52 3.60 3 '74 6-73 15'06 4'92 6'44 2 -0 2'0 1 '4 0 '4 0'8 1'1 0'7 2 '5 2 '5 0.7 2'2 1.8 1'9 B.P. Sul- phuric Acid Test, Before Stirring. -- red brown, tinged violet red brown, tinged violet intense violet light brown brown orange bruwr wown, tinged violet dark brown orange violet brown brown range, tinged violet violet B.P.Sul- phuric Acid Test, After Stirring. -~ violet violet ntense violet nearly black vsndyke brown red brown brown violet intense van- dyke brown brown violet brown vivid violet vivid violet INOs+H280 Teat, Before Stirring. __ orange pink brownish pink bright violet pale brown brown light brown )range brown pale brown pale orange light brown pink light brown brown HNO3+ &SO4 Test, After Stirring. -- vivid salmon pink vivid salmon pink, but not so vivid greenish brown very pale pink brown orange pale pink pale orange very pale brown pale brown light brownish pink pale orange pink pinkish orange As regards the figures, it will be seen how generally uniform they are, there being no sharply-defined property by which pure cod-liver oil can be identified.Haddock oil has a high iodine number, and possesses marked drying properties. The nitric and sulphuric acid test gave the most promising colour reaction. The author has not met with an oil other than genuine cod-liver oil which gives the charac teris tic coloration. w. P. s. Essential Oil of Boldo. E. Tardy. (Journ. Pharrn. Chim., 1904, xix., 132-136.) The leaves of the boldo (Boldoa fragrans, Pneumus boklus) have been used since 1872 in France as a, therapeutic agent in diseases of the liver. They contain aTHE ANALYST. slight amount (0.5 gramme in 20,000) of an dkaloidal substance, boldine, together with citric acid, glucose, tannin, and about 2 per cent.of an essential oil. The author has studied the composition of a specimen of this oil extracted by himself from 12 kilo- grammes of the dried leaves. It was a very mobile liquid, with a slight yellowish-green colour and a fragrant odour. Its specific gravity was 0.876 at 15" C., and its optical rotation in a 100 millirnetre tube, uD = - 6" 30'. When submitted to fractional dis- tillation it yielded three main fractions, boiling respectively at 155" to 160" c., 175" to 177" C., and 215" to 220" C. I t consisted, in the main, of a divalent dextro- rotatory hydrocarbon of the pinene series, and of a tetravalent laevo-rotatory terpene, with smaller amounts of cuminic aldehyde, terpilenol, end probably a little eugenol. Acetic acid and a sesquiterpene were also recognised.C. A. M. The Adulteration of Saffron. A. Nestler. (Zeit. fiir Urttersuch. der Nahr. und GenussmitteE, 1903, vi., 1034-1035.)-Safflower and marigold petals appear to be the most common adulterant8 of saffron, but the authors have also met with samples containing iron oxide, barium sulphate (12-93 per cent.), potassium nitrate (27.05 per cent.), and borax. Some samples of saffron had peculiar crystals on the stigma. These crystals were yellow or colourless in appearance, and when examined under the microscope were seen to be either flat plates, rhomboidal prisms, or pyramids in shape. They were soluble in water, but insoluble in alcohol and in ether. The author considers them to be a natural constituent of saffron. w. P. s. The Ash of Certain Drugs. J. C. Umney.(Pharm. Journ., 1903, lxxi., 879, 88O).-The paper by Chattaway and Moor (ANALYST, 1903, xxviii., 202-212) shows that workers are agreed as to the average ash of drugs with but very few exceptions. The most acceptable percentage for some drugs, however, still appears to be doubtful, and the author gives a few observations on the differences which occur in these latter, and the probable reason for their existence. Cimicificga Rhizome.-Well-brushed samples of the root gave an average of 95 per cent. of ash. Some specimens, having a large proportion of rootlets, yielded as much as 1305 per cent., and one sample even as high as 17.4 per cent. This shows the necessity of cleaning this and other roots before utilization in pharmacy. Eight per cent. of ash as a maximum is considered a reasonable limit.CoZocylzth PuZp.-No great reliance should be placed on the amount of ash yielded by this substance, as it may vary from 7.2 to 13.5 per cent., according to its source. A microscopical examination, and ascertaining that the sample is free from fixed oil, are the best means for detecting adulteration. Conium Leaves.-Widely varying percentages have been recorded, but the difference appears to be due to the proportion of leaves and stalks in the drug. The leaves have from 13 to 14.5, and the stalks from 16 to 18 per cent. of ash. Sixteen per cent. is suggested as a maximum limit. Cubebs.-Here, again, the stalks have a higher ash than the fruit, the amount for the former being from 10 to 11 per cent., and for the latter from 5.5 to 6.5 perTHE ANALYST.95 cent. A maximum limit of 7 per cent. is considered fair. Elaterium-A previously suggested limit of 14 per cent. may reasonably be reduced to 10 per cent. or slightly lower, the average being about 6 per cent. Provided the cucumbers be properly cleanged and prepared, the ash need not exceed 5 per cent. Loss of volatile oil in drying also increases the ash. Jaborandi Leaves.-The ash should not be more than 7 per cent. LobeZia.-The leaves contain from 10 to 12 per cent. ol ash and the stalks about 3.5 per cent. As, however, the leaves yield a much higher proportion of extractive and alkaloid than the stems, as high a ratio as possible of leaves to stems is to be recommended. From 9 to 10 per cent. of aih is a fair maximum, although samples giving as much as 12 per cent. cannot be objected ‘to. Rhubarb.-The ash varies enormously, and the author thinks it is not a matter of great importance to fix an ash standard for this drug. Reliance should be placed on more definite chemical characters for valuation purposes. Stramonium Leaves.-The amount of ash is considerably influenced by the time of collection of the leaves, and also by the soil on which the plants are grown and the method of manuring. Quantities from 13.6 to 20.3 per cent. have been obtained, and probably the latter figure ought to be taken as a limit, unless it can be shown that a drug with a high ash is deficient in alkaloidal strength. W. P. s. Distinction between Distilled and Ordinary Water in Artificial Mineral Waters. W. Lohmann. (Zeit. fiir 3fle.ntl. Chem., 1903, ix., 458, 459.)-The method devised by J. M. Silber (Farmceft, 1903, xi., 691), based upon the determination of silica in the mineral water, is considered to be untrustworthy. The distilled water employed in the manufacture of artificial mineral water is frequently aerated before use by passing it through sand filters, from which it dissolves traces of silica. The chemicals (sodium carbonate, sodium chloride, etc.) used are rarely free from traces of silica, and earthenware or glass vessels are employed for making up the solutions. In this way a mineral water actually made with distilled water may contain appreci- able quantities of silica. Furthermore, sodium silicate, as one of the constituents of natural mineral water, is added to the artificial water. w. P. s.

ISSN:0003-2654    

DOI:10.1039/AN9042900088

出版商:RSC    

年代:1904

数据来源: RSC

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THE ANALYST. 95 ORGANIC ANALYSIS. Oils from Various Fruits and Seeds. G. Fendler. (Zed. fiir Untersuch. der Nalar. und Genussmittel, 1903, vi., 1025-1027.) Candle-nut Oil.-The nuts of the candle-nut tree, Aleurites moluccana, yield an oil which, according to the observations of various authors, gives widely different chemical values, the variations apparently being due to the fact that there are several species of Alezwites.96 THE ANALYST. The following constants relate to a specimen of the oil extmcted from the nuts with ether : Specific gravity at 15O C. ... ... ... ... 0.9254 Solidifying point ... ... ... ... ... - 15.0 c. Acid value ... ... ... ... ... ... 0.97 Saponification value ... ... ... ... ... 194.8 Iodine value ... ... ... ... ... ... 114.2 Reichert -Meissl value ...... .. ... 1.2 Melting-point of fatty acide ... ... ... ... 18.0 c. Solidifying point of fatty acids ... .,. ... 15.5 C. The oil was bright yellow in colour, and had a disagreeable taste and odour. It Oil of Acrocomia Vznifera 0erst.-The seeds of this Nicaraguan fruit yield ~t After a long time had very marked drying properties. bright yellow oil, which, on standing, deposits feathery crystals. the whole oil becomes solid. The oil gave the following figures : ... ... 0,9136 Specific gravity at 25' C. ... ... Melting-point ... ... ... ... ... ... 25.0' C. Solidifying-point . . , ..* 1.. ... ... 17.0' C. Acid value ... ... ... ... ... ... 1.69 ... 246.2 Saponification value ... ... ... ... Iodine value ... ... ... ... ... ... 25.2 Reichert-hfeissl value ...... ... ... ... 5.0 By repeated crystallization of the above-mentioned crystals from alcohol, product was obtained which yielded fatty acids having a constant melting-point of 54.5' C. after many recrystallizations, and therefore probably consisted of myristic acid. The oil has a, certain resemblance to cocoanut oil. Melon-seed OiZ (from Togo).-A sample extracted from the seeds with ether gave the following results : Melting-point ... ... ... ... ... ... 5.5" c. Solidifying-point ... ... ... ... ... 5.0" c. Saponification value ... ... ... ... ... 193.3 Melting-point of fatty acids ... ... ... ... 39-0' C. Solidifying-point of fatty acids ... ... ... 36.0" C. Acid value ... ... ... ... ... ... 4.81 Iodine value ... ... ... ... ... ... 101.5 w. P. s. The Furfural Reaction of Sesame Oil.P. Lehnkering. (Zeit. fur ofcnth. Chem., 1903, ix., 436, 437).-During the examination of a series of pure seaam6 oils it was found that, whilst the whole of the samples gave normal results as regards their iodine numbers and refractive indices, certain of the oils yielded but feeble colora- tions when the furfural reaction (ANALYST, xix., 47) was applied. Indicating the intensity of the coloration given by the oils having the strongest reaction by the arbitrary number 10, it was estimated that some of the oils gave a coloration of lessTHE ANALYST. 97 than 1. Oils extracted from the seeds with ether gave colour reaotions having an intensity of 5 to 8 in the above-mentioned scale. w. P. s. These latter oils would be difficult to detect in margarine. The Condition of Phosphorus in Certain Food Materials and Animal Bye- Products, with Special Reference t o the Presence of Inorganic Forms.E. B. Hart and W. H. Andrews. (Amer. Chem. Joum., xxx., 470.)-The authors have tried to find a method of determining the phosphorus present in the form of inorganic phosphates in materials which contain organic compounds of phosphorus, such as proteids, nucleic acid, and lecithin, and have finally adopted the following, which reduces the decomposition of these bodies to a minimum: Five grammes of t h s sample are vigorously shaken for fifteen minutes with 125 C.C. of 0-2 per cent. hydro- chloric acid. The solution is then decanted through a, filter-paper into a 500 C.C. flask, and the residue washed with water until the flask is filled to the mark.This washing should take about three hours. Of the filtrate, 200 C.C. are neutralized with ammonia, using litmus as indicator, and 10 grammes of ammonium nitrate are added. The solution is warmed to 65" C. ; 2 C.C. nitric acid (specific gravity 1-20) and 25 C.C. neutral ammonium molybdate solution are added; the whole is kept at 65" C. for fifteen minutes, then allowed to stand for one hour at room temperature before filtering. The precipitate is converted into magnesium pyrophosphate, which is dis- solved in dilute nitric acid, and reprecipitated to remove any magnesium oxide due to organic compounds of magnesium present in the first precipitate. Using the above method, the authors determined inorganic phosphorus in a* number of feeding materials, and conclude that animal feeding-stuffs, when free from bone as well as vegetable materials, contain practically no inorganic phosphorus.Commercial meat meal, however, which is liable to contain varying quantities of bone meal, does contain inorganic phosphorus. They also find that germinating grains are rich in soluble organic phosphorus, and that germination, extending over two weeks, of oats, corn, and wheat, does not transform any organic into inorganic phosphorus compounds. A. G. L. A Rapid Method of determining Halogens in Organic Compounds. H. H. Pringsheim. (Berichte, 1903, xxxii., 4244-4246.)-About 0-2 gramme of the substance is mixed with sodium peroxide in a steel crucible provided with a lid in which is a small hole.The covered crucible is placed in a porcelain dish in which is sufficient water to reach nearly to the top of the crucible. A red-hot wire is then passed through the hole in the crucible lid in order to ignite the mixture, after which the crucible and lid are turned over so as to be completely immersed in the water. The dish is now covered with a clock-glass, and heated until bubbles of oxygen are no longer evolved. The liquid is then filtered, and the filtrate poured into an excess of sul- phurou$ acid, which reduces higher halogen acids to hydrochloric acid, etc. Finally it is treated with nitric acid, and the halogen precipitated with silver nitrate in the usual way. The amount of sodium peroxide required for the oxidation depends on the proportion of hydrogen and carbon in the substance under examination. Substances98 THE ANALYBT. containing 75 per. cent. or more of carbon and hydrogen require eighteen times their weight of sodium peroxide, and those containing 50 to 75 per cent. sixteen times their weight. Substances containing only 25 to 50 per cent. of carbon and hydrogen are first mixed with half their weight of sugar or naphthalene, whilst those with still less are mixed with an equal weight of one of these bodies. This mixture is then mixed with sixteen to eighteen times its weight of sodium peroxide. C. A. M.

ISSN:0003-2654    

DOI:10.1039/AN9042900095

出版商:RSC    

年代:1904

数据来源: RSC

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98 THE ANALYBT. INORGANIC ANALYSIS. Reactions distinguishing between Cobalt and Nickel. G. Gubrin. (Jown. Yharm. Chim., 1904, xix., 139.)-If a solution of a cobalt salt be treated with an excess of potassium hydroxide, and a 2 per cent. solution of iodine in potassium iodide be added until the supernatant liquid becomes yellow, the whole of the cobalt will be deposited in a few seconds in the form of the black hydrated sesquihydroxide. Nickel salts under the same conditions yield the light-green hydroxide. The same hydroxides are formed on adding potassium hydroxide in excess and then the iodine solution to the precipitates produced in solutions of cobalt or nickel salts by ferro- cyanides, carbonates, and phosphates of the alkali metals. On the other hand, when the ferricyanides are treated with potassium hydroxide both become black, yielding the respective hydrated sesquihydroxides of nickel or cobalt.The reaction is almost instantaneous in the case of nickel ferricyanide, but slower with cobalt ferricyanide. C. A. M. A New Reaction of Molybdenum. E. Lecocq. (Bzdl. de I'Ass. bdge Chim., 1903, xvii., 412-414.)-Diphenylcatrbazide, recommended by Caxeneuve (ANALYST, xxv., 331) as a very sensitive reagent for mercury, copper, iron (in the ferric state), and chromic acid, can also be employed for the identification of molybdenum. The solution of an alkali molybdate in 30 to 40 C.C. of water is acidified with 2 or 3 drops of strong hydrochloric acid, and treated with an alcoholic solution of diphenylcarba- zide prepared several days previously. On the addition of the first drop a brilliant violet-indigo coloration is produced, which increases in intensity on the addition of more of bhe reagent, and eventually a precipitate of the same colour is formed.This. reaction, which does not take place in the presence of strong acids or alkalies, is capable of detecting 0.007 gramme of ammonium molybdate in a litre of water. In the author's opinion a compound is first formed between the alcohol and the diphenyl- csrbazide, and this gives the coloration with the molybdenum. This view receives support from the facts that no reaction is obtained with a benzene solution of diphenylcarbazide, and that the colorations can be varied by replacing ordinary alcohol by other alcohols of the fatty series. Thus, with methyl alcohol the colour is bluish indigo ; with propyl alcohol, violet ; with butyl alcohol (liquids immiscible), violet red ; with isobutyl alcohol, violet red ; and with amyl alcohol the upper layer is rose and the lower colourless.None of these colorations is sufficiently marked to serve a8 a means of distinguishing between the different alcohols, except in the case of amyl alcohol, which can bo readily identified by this test. C. A. M.THE ANALYST. 99 Quantitatdve Separation of Metal$ by Heans of Pemulphatee. G. v. Knorre. (Zeit. and. Chern., 1904, xliii., 1-l4.)-The method of determining man- ganese by precipitation with ammonium persulphate (ANALYST, xxvii., 68) has now been tested by the author, to determine to what extent it can be used in the separa- tion of different metals.Experiments described in detail show that it is not possible to effect in this way a sharp separation of manganese from copper, zinc, cadmium, niokel, or magnesium. In the case of chromium, however, good results can be obtained. Thus, if a solution containing ohrome alum and manganese sulphate be treated with an excess of ammonium persulphate and heated to boiling, the chromium salt is completely oxidized to chromia acid, whilst the manganese is quantitatively precipitated as peroxide. In a test experiment 50 C.C. of a solution of chrome alum containing 0.2772 gramme of chromic oxide was mixed with 100 C.C. of a solution containing 3.102 grammes of pure manganese ammonium sulphate, and the liquid boiled for six minutes with 100 C.C.of a solution containing about 6 grammes of aamonium persulphate. The amount of the oxide (Mn,O,) left on ignition of the precipitate was 0.6058 gramme, as against the theoretical 0.6055 gramme ; whilst the chromium oxide (Cr,O,) obtained from the filtrate weighed 0-2774 gramme, instead of the theoretical amount, 0.2772 gramme. In the author's opinion this method is more rapid and accurate than any other known method of separating manganese and chromium. C. A. M. The Determination of Bromides in the Presence of Chlorides. Imbert and Dumolmd. (BaEZ.. Phum. du. Sud-Est ; through Ann. de Chim. anal., 1904, ix., 21,22.)-Part of tha solution containing the mixed salts is treated with silver nitrate, and the weight of the precipitated silver chloride and bromide determined.Another (equal) portion of the original solution is then boiled for thirty minutes with ammonium persulphate, which decomposes the bromide, the larger part of the bromine being set free, and the remainder converted into bromate. The solution is again treated with silver nitrate, and the amount of precipitated silver chloride deducted from the weight of the former to obtain the amount of silver bromide. The authors have proved that the ammonium persulphate does not liberate any chlorine or convert any trace of chloride into chlorate. On the other hand, a solu- tion of ammonium persulphate, after being boiled by itself for thirty minutes, gives a slight precipitate with silver nitrate. To obviate any error from this source 8 little nitric aoid should be added after the boiling to destroy undecomposed persulphate.C. A. M. Fractional Combustion of Gas Mixtures - contqining Hydrogen by Means of Heated Palladium Wire. F. Richardt. (Zeds. A w g . Chm., xxxviii., 65.)- The author shows that methane is not oxidized in its mixture with air when led over heated palladium wire if the temperature is kept below 450° C., and that if the time of oontact is short practically no combastion bakes place even at 600" to 650" C. Ethane behaves in a similar way, but burns a little more readily. Ethylene is burnt to some extent at as low a temperature as 300' C. It follows from them observations that in mixture8 of methane or ethane, but not of ethylene, with hydrogen the latter100 THE ANALYST. may be burnt completely without attacking the hydrocarbon, by leading a slow current of the gas, mixed with air, ov0r palladium wire kept at a temperature approaching 450" C.A. G. L. Fractional Combustion of a Mixture of Methane and Hydrogen by Winkler's Method. I(. V. Charitohkof. (Joum. SOC. Phys. Chim. R., xxxiv., 710 ; through Chem. News, lxxxviii., 282.)-The author finds that the best way of removing hydrogen from mixtures containing methane is by means of palladium sponge at a temperature of 70" C., not 120" C. Even at this low temperature, and when the quantity of hydrogen present is small, some of the methane is burnt, and hence the carbon dioxide formed should be determined. To mixtures containing much hydrogen the method is inapplicable. A. G. L. A New Volumetric Method of determining Nitric Nitrogen.L. Debour- deaux. (BUZZ. SOC. Chim., 1904, xxxi., 3-6.)-This method is based on the oxidation of oxalic acid by nitric acid in the presence of sulphuric acid and manganese sulphate, with the formation of nitrous oxide and carbon dioxide. When the solution contains more than 20 per cent. by volume of sulphuric acid the reaction takes place in accordance with the equation whilst with less than that proportion of sulphuric acid, nitrous oxide is produced- The most favourable conditions for the reaction are when the solution contains from 4 to 6 grammes of manganese sulphate and 11 to 14 C.C. of sulphuric acid per 100 C.C. The temperature should be gradually raised to about 94' C. In making a determina- tion, about 0.5 gramme of thenitrateis mixedin a flask with 50 C.C.of a solution con- taining 35 to 40 grammes of crystalline oxalic acid, 50 grammes of manganese sulphate, and 120 C.C. of sulphuric acid, specific gravity 1.84 ( 6 6 O Be.) per litre. The flask is placed in a cold-water bath, and slowly heated under a reflux condenser. When the water in the bath boils (which should take at least thirty minutes) and all evolution of gas has ceased, the reaction is complete. The residual oxalic acid in the solution is then titrated with standard potassium permanganate solution (about 20 grammes per litre), and the difference between this result and that given by a preliminary titration of 50 C.G. o€ the oxalic reagent shows the amount of oxalic acid destroyed by ihe nitric acid present. The method is shown to yield closely concordant results under the conditions described above.An addition of from 1 to 5 grammes of potassium sulphate per 100 C.C. is without noticeable effect, whilst potassium bisulphate does not act in the same way as free sulphuric acid. Ammonium salts in the proportions in which they occur in artificial manures have also no perceptible influence on the reaction, which is also the case with small amounts of chlorides, such as occur in commercial nitrates. Large quantities of chlorides, however, lead to some destruction of oxalic acid, and ought to be removed by precipitation with silver. 3H2C20,.2H20 + 2KN0, + H,SO, = 10H,O + &SO, + 6C0, + 2 N 0 , 4H2C204.2H20 +3KNO, + H,SO, = 13H20 + K,SO, + 8C0, + N,O.THE ANALYST. PO1 Vanadium sulphate can replace manganese sulphate in this reaction, the con- ditions then being as follows: Amount of sulphuric acid, 2 to 6 C.C.; and amount of vanadium sulphate, 0.15 to 0525 gramme per 100 c.c, I n this case also the tern- perature must be raised very gradually. C. A. M. The Determination of Nitrites in Absence of Air. I. IC. Phelps. (zeits dnorg. Chem., xxxviii., 113.)-The method described is a modification of that of Dunstan and Dymond (Phrm. Journ., xix., 741), and consists in allowing potassium iodide to act cm the acid solution of the nitrite, afterwards determining the iodine liberated. It is carried but in a 250 C.C. flask provided with a rubber stopper, which carries a tap-funnel rand a wide exit-tube; this last is expanded into a bulb just above the stopper, and then bent twice at right angles ; the bulb serves to prevent mechanical loss during boiling, For the determination, an excess of standard arsenious acid solution and 25 c,c.of a concentrated sodium carbonate solution are introduced into the flask; the stem of the tap-funnel is completely filled with water, and the liquid in the flask is boiled for five to eight minutes in order to expel all air. The end of the exit-tube is then plunged into a deep column of mercury, the boiling in- terrupted, and the flask cooled by immersing it in water or ice. Through the tap- funnel 7 C.C. of sulphuric acid (1 : 4) are allowed to flow into the flask; the flask is raised so that the exit-tube no longer dips into the mercury, but into a layer of water placed above it ; the funnel is carefully washed free from acid, and the solution of the nitrite to be examined addtea. 'Enough sulphuric acid (about 5 C.C. of 1 : 4) is then added to make the contents of the flask acid, followed by an excess of potassium bicarbonate. The liquid is then again boiled for five minutes to completely expel all nitric oxide, aIlowed to cool, and titrated with standard iodine solution. The method was checked against that of Kinnicut and Nef (Awzer. Chem. Jouru., v., 388). It gives satisfactory results, slightly above the theoretical. A. G. L.

ISSN:0003-2654    

DOI:10.1039/AN9042900098

出版商:RSC    

年代:1904

数据来源: RSC

摘要:

102 THE ANALYST. THE INSTITUTE OF CHEMISTRY OF GREAT BRITAIN AND IRELAND. THE twenty-sixth Annual Geqeral Meeting of the Insbitute of Chemistry was held at 30, Bloomsbury Square on Tuesday, March 1, Mr. David Howard, President, in the chair. The annual accounts, with the report of the auditors, having been submitted by Mr. A. Gordon Salamon, Hon. Treasurer, and duly received, Professor TILDEN moved the adoption of the annual report of the Council, at the same time comment- ing on the general progress of the Institute. He considered it satisfactory to note that notwithstanding the increasingly stringent regulations a8 to training, the very high standard of the examinations, and in spite of the loss of members by death, the number of Fellows and Associates-viz., 1,098-was 251 higher than in 1894.He also commented on the scheme for the promotion of the better training of technical chemists now under the consideration of the Council. Mr. FRISWELL seconded the report, which was then adopted. The ballot for the election of Censors having been taken, Dr. Thomas Stevenson, Professor J. Millar Thomson, Professor W. A. Tilden, and Dr. J. A. Voelcker were declared elected. The meeting proceeded to appoint Ron. Auditors, and Messrs. A. R. Ling, C. H. Cribb, and R. E. Alison were appointed. The P~SIDENT then delivered his address, in which he commented on the work of the Council during the past year, on the present position of the Imtitute, and on the work the Council at present have in hand. He reported that the number of candidates for the examinations continued to increase, and that it had been found necessary to make arrangements for holding an extra, examination in April of this year, in order to avoid an excess of candidates in July.The Council, with the help of the new Treasurer, had given particular attention to the finances of the Institute. The heavy expenditure on examinations had rendered it necessary to raise the fees, but the Council had given time for students already in course of training to become registered under the lower fees. The alterations would not be such as to impose a great hardship on the individual candidate, and yet by the time the new regulations were in full operation the fees received would probably meet the cost of the examina- tions. It had always been felt that the maintenance of the efficiency of the examinations was a primary duty of the Institute, and in endeavouring to organize the profession, by bringing together the properly trained and competent, it had been necessary for the Institute to afford all possible facilities for this object.The principal duty of the Institute waa to promote the better education and examination of Public and Technical Analysts. Mr. Howard showed how the Institute had carried out this object in promoting the better educa- tion of professional chemists generally and Public Analysts in particular. He men- tioned incidentally that from carefully collected information he had ascertained that in England and Walee 93.5 per cent., in Scotland 89.5 per cent., and in Ireland 84.7 per cent. of the appointments as Public Analysts under the Sale of Food and Drugs Acts were held by Fellows and Associates of the Institute.However, no special provision had hitherto been made in respect to the training and examination Hitherto they had been conducted at a heavy loss.TEE ANALYST. 103 of technical chemists, and the Council were at the present time paying particular attention to this matter. An outline of the proposed scheme had been published in the Proceedings, and details would be published shortly. The special committee which had the matter in hand would hold a conference during the present year with manufacturers and others interested in the progress of scientific industries. The difficulty was to bridge over the gap between the scientific training and the practicd work of the technical chemist; he had to learn to think in tons instead of grammea The whole question would require most careful consideration, but it was hoped that the Institute would be able to afford assistance in overcoming the difficulty. The officers and members of Council for the ensuing year were duly elected as follows : President: David Howard.Vice-presidents : George Beilby ; Frederick Daniel Chattaway, M.A., D.Sc. ; Percy Faraday Frtmkland, Ph.D., F.R.S. ; Edmund Albert Letts, D.Sc. ; Edmund James Mills, D.Sc., F.R.S. ; John Millar Thomson, LL.D., F.R.S. Ron. Treasurer ; Alfred Gordon Salamon, A.R.S.M. Members of Cou~zciE: Alfred Henry Allen ; Leonard Archbutt ; Edward John Bevan ; Bertram Blount ; Horace T. Brown, LL.D., F.R.S. ; James Cameron ; Alfred Chaston Chapman ; Edwy Godwin Clayton ; James Kear Colwell ; Edward Divers, M.D., F.ES. ; James Johnstone Dobbie, M.A., D.Sc. ; Bernard Dyer, D. Sc. ; Thomas Fairley ; Richard John Friswell ; Arthur George Green ; Alfred John Greenaway ; Oscar Guttmann ; Henry James Helm, I.S.O. ; Herbert Jackson ; William Walker James Nicol, M.A., D.Sc. ; Frederic James Montague Page, B.Sc., A.R.S.M. ; William Jackson Pope, F.R.S. ; Alexander Scott, D.Sc., F.R.S. ; David Alexander Sutherland ; Leo Taylor ; Edward William Voelcker, A.R.S.M. ; Sydney Young, D.Sc., F.R.S.

ISSN:0003-2654    

DOI:10.1039/AN9042900102

出版商:RSC    

年代:1904

数据来源: RSC

摘要:

TEE ANALYST. 103 REGULATIONS MADE BY THE SECRETARY OF STATE FOR THE MANUFACTURE OF ELECTRIC ACCUMULATORS. FACTORY AND WORKSHOP ACT, 1901. THE following is a brief summary of these Regulations, which are to apply to all factories and workshops, or parts thereof, in which electric accumulators are manu- factured, the manufacture of these having been certified in pursuance of the Factory and Workshop Act, 1901, to be a dangerous occupation: Every room in which casting, pasting, or lead-burning is carried on is to contain a specified air-space for each person employed, and is to be capable of through ventilation. The various processes are to be cazried on in such manner as to secure effectual separation from one another and from any other process. The floors of the rooms in which manipulation of dry compounds of lead or pasting is carried on are to be constructed with an impervious material, must be kept constantly moist while work is being done, and be washed with a hose-pipe daily.Every melting-pot is to be so arranged as to remove the fumes and hot air from the workrooms. Lead ashes and old plates must be kept in receptacles specially provided for the purpose. Manipulation of dry com-104 THE ANALYST. pounds of lead must only be done in a closed apparatus, or one arranged with a n exhaust draught, so as to prevent the escape of dust into the workroom, or at a bench provided with an efficient exhaust draught to draw the dust away from the worker, and with a grating on which each receptacle of the compound of lead in use at the time shall stand.The benches at which pasting is done shall be covered with some impervious material. No womm, young perBon, or child shall be employed in the manipulation of dry compounds of lead or in pasting. A duly qualified medical practitioner shall be appointed by the employer, and every person employed in a lead process shall be examined once a month by him. H e shall have power to suspend persons from employment in any lead process, and no such person after suspension shall be employed in a lead process without written sanction entered in the health register by the appointed surgeon. A health register shall be kept, and shall contain a list of all persons employed in lead processes. The appointed surgeon will enter in the health register the dates and results of his examinations of the persons employed and particulars of m y directions given by him.Overalls shall be provided for all persons employed in manipulating dry compounds of lead ; these shall be washed or renewed once every week. The employer shall provide and maintain a cloakroom, in which workers can deposit clothing put off during working hours, and with suitable arrangements therein for the storage of overalls ; also a dining-room, unless the factory is closed during meal hours. No person shall be allowed to introduce, keep, prepare, 01: partake of any food, drink, or tobacco (with the exception of a sanitary drink) in any room in which a lead process is carried on. The employer shall provide and maintain a lavatory, with soap, nail-brushes, towels, there being at least one lavatory basin for every five such persons.A constant supply of hot and cold water is to be laid on to each basin. These besins may be replaced by troughs of enamel or similar smooth impervious material, of a total length of 2 feet for every five persons employed, fitted with waste-pipes and without plugs, with a sufficient supply of warm water constantly available. The lavatory shall be kept thoroughly cleansed, and shall be supplied with a, sufficient quantity of clean towels once every day. Before each meal and before the end of the day's work, at least ten minutes, in addition to the regular meal times, shall be allowed for washing to each person who has been employed in the manipulation of compounds of lead. Sufficient bath accommodation shall be provided for all persons engaged, with hot and cold water laid on, and a sufficient supply of soap and towels, or in lieu of this, in consideration of the special circum- stances, local public baths, when conveniently near, may be utilized. The floors and benches of each workroom shall be thoroughly cleansed daily at a time when no other work is being carried on in the room. Next follow a number of regulations providing that the employes obey the before- mentioned rules and arrangements. Copies of the Regulations, price ld.,.by post lid., may be purchased of Eyre and Spottiswoode, East Hardiog Street, Fleet Street, London, E.C. ; or Oliver and Boyd, Edinburgh ; or E. Ponsonby, 116, Grafton Street, Dublin.

ISSN:0003-2654    

DOI:10.1039/AN9042900103

出版商:RSC    

年代:1904

数据来源: RSC