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11. |
Reviews |
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Analyst,
Volume 33,
Issue 393,
1908,
Page 486-488
J. C. Thresh,
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PDF (250KB)
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摘要:
486 THE ANALYST. REVIEWS. INFLUENCE OF FOOD PRESERVATIVES AND aRTIFICIAL COLOURS OX DIGESTION AND HEALTH, others. U.S. Department of Agriculture. IV. Benzoic Acid and Benzoates. By H. W. WILEY, M.D., and I n previous reports Dr. Wiley has dealt with sulphurous acid, boric acid, and salicylic acid, and the experiments recorded in this volume were conducted on exactly the same lines, and apparently with the same set of men in the I ‘ poison squad.” The results obtained will be referred to later. They undoubtedly possess a certain value, but they admit of a good deal of criticism-criticism which, in the minds of many, vitiates the results of the whole of the experiments. In the first place, the preservative was administered in doses as large as, and far exceeding, the maximum medicinal dose, and the daily quantity was administered in a capsule without any admixture or dilution.How can the influence of small fractions of a medicinal dose, administered a t more frequent and irregular intervals, and taken mixed with large quantities of food, be safely inferred from such experiments? One can quite imagine that pro- portionately large doses of common salt, given by Dr. Wiley’s method, would produce alarming symptoms, and common salt therefore be declared absolutely injurious to health. In the second place, the experiments were not efficiently controlled. There were fore and after periods during which the men were under observation ; but, to make the results conclusive, there should have been a, larger number of men, half of whom only should have taken the preservative, and no member should have known whether he was taking the preservative or not.The necessity for such a course is obvious from the report itself, which throws doubt even on the suitability of the men selected. For example, of one man it is said : L L He had a very vivid imagination, and the least excitement developed almost any symptoms. which his fancy might dictate.” Of mother it is said that he had to take laxatives throughout the experi- ment, and drank large quantities of water. He had a very vivid imagination, andTHE ANALYST. 487 some of the symptoms which he noted were entirely irrelevant.” Another of the men had only j u t recovered from an attack of measles. I t is obvious, therefore, that Dr. Wiley’s results, whilst they can be taken as fairly conclusive of the effect of large and often excessive doses (1 gram to 2.5 grams) of benzoic acid or the equivalent of sodium benzoate given in a certain manner to certain individuals, produced upon those individuals, they may not be generally accepted a6 conclusive of the effect of very much smaller quantities taken in an entirely different manner by any particular class of the community.The effects produced by the administration of these large quantities were not uniform, but in most cases the men at a late stage, when specially large doses were being given, suffered from nausea and headache; vcpiting was produced in three cases. Some complained of weakness and burning and irritating sensations in the oesophagus, and some developed enormous appetites. The physiological effects ascertained, by weighing, by examining the faxes and urine, etc., were very slight (the tables referring to these take up most of the report), but, on the whole, Dr.Wiley thicks they indicate that benzoic acid and benzoate5 administered in large doses cause some slight disturbance of the normal metabolic processes. Benzoic acid appeared to produce injurious effects more rapidly than the sodium salt. His final conclusion is ‘( that in the interests of health both benzoic acid and benzoate of soda should be excluded from food products.” Dr. Wiley in the introduction attaches great importance to the results of certain investigations made in the Bureau, in collaboration with manufacturers, which ‘‘ have shown that there is not a single article of food which has been commonly preserved by means of benzoic acid or benzoate of soda which cannot be preserved and offered to the consumer in perfect condition without the aid of any chemical preservative.” This is admittedly the case, aed required no proof.The manufacturer of any article of food or drink can so prepare it that it will keep good until supplied to the consumer, but it does not follow that it will keep good as long as the consumer desires after the package has once been opened and the contents exposed to air. It is this latter difficulty which requires to be surmounted, and until it is surmounted, or the use of preservatives is absolutely prohibited by Parliament, preservatives will continue to be used by manufacturers.If not used unnecessarily or in needlessly large quantities, it would be difficult to convince the court, from the results of Dr. Wiley’s experiments, that harm would result from the use of benzoic acid as a preservative. J. C. THRESH. HEVEA BRAZILIENSIS, OR PARA RUBBER : ITS BOTANY, CULTIVATION, CHEMISTRY, AND DISEASES. By HERBERT WRIGHT, A.R.C.S., F.L.S. Third edition, with plates, diagrams, contents table, and index + 298 pages. Colombo : Messrs. A. M. and J. Ferguson ; London: Messrs. Maclaren and Sons. 1908. Price 10s. net. There is, perhaps, no more striking illustration of the rapid growth in extent and importance of the rubber-planting industry than the appearance of the third edition of Mr. Wright’s work so hard on the heels of the second. As late Controller OE the Government Experiment Station in Ceylon during the critical period of488 THE ANALYST.experimental rubber-planting, and as present editor of the India-Rubber Journal, no man, perhaps, is able to speak with greater authority concerning all that pertains to the technical, scientific, and economic aspects of rubber-planting and plantation rubber. Although only two years have elapsed since the second edition saw the light, the present edition-which practically contains twice as much matter as the former one-is in many respects a new work, as, in addition to the old matter, it records the scientific and technical doings of two most strenuous years in a nascent industry of the highest importance. The work will be of interest to all chemists, and indispensable to those whose work brings them in contact with the rubber industry.To analysts in particular, the full collection of analytical data bearing on soils suitable for rubber-growing, on manuring, on the constitution and analysis of various kinds of latex and of the rubbers produced from them, on the methods of coagulation and preparation generally, and on the constitution of finished rubber articles, will be of special interest. The illustrations are nunierous, and well calculated to give the reader an excellent idea of every branch of the ,:rude rubber industry. The volume is, however, worthy of somewhat better printine and binding. DIE CHEMISCHE ANALYSE. Vols. IV. and V. : Elektroanalytische Schnellmethoden. By Dr. A. FISCHER. Stuttgart : Ferdinand Enke.1908. Price 9.40 marks. I n view of the great advances which have been made recently on the rapid electro-deposition of metals, the present very useful volume by Dr. Fischer, in which all the literature of the subject is collected, supplies a distinct want. The theory of metallic reduction by means of the electric current is discussed, and in this connection reference is made to the little understood ‘‘ supertension,” or overpotential. Some metals, for example, show much higher reducing power when used as electrodes than others, the reducing aption being explained, by saying that these metals have a high supertension. A full description, illustrated by means of diagrams, of the difYerent forms of apparatus employed by various workers is given. Roughly, there are three methods : the rotation of the anode or cathode; the employment of a mercury cathode, the anode being rapidly rotated; and the rotation of the electrolyte. All the methods in the hands of those who understand them give good results. In America the mercury cathode as suggested by Edgar Smith is generally used. I n this country and Germany the rotating anode or cathode is more frequently employed. A full description is given of the method first suggested by Dr. Sand for grading the potential by means of an auxiliary electrode. This electro-process has been found of value in the separation of metals by purely electro-chemical means, and, as it is usually adopted in conjunction with rotating electrodes, the separations can be carried out extremely rapidly. The potential is maintained at a certain level while one metal is being deposited; the electrode is then changed, the potential increased, and the other metal deposited. The latter part of the book deals entirely with the deposition and separation of the metals. F. M. PERHIN. P. SCHIDROWITZ.
ISSN:0003-2654
DOI:10.1039/AN9083300486
出版商:RSC
年代:1908
数据来源: RSC
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