SYNTHETIC CHEMISTRY 1828-1928
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348 plants, as work at the Rowett Institute at Aberdeen has shown. Heavily cropping the soil tends to deplete it of iodine, and manuring with either dung or arti- ficial fertilisers causes a marked loss of iodine. The amount of iodine in fresh water and in sea water has been the object of much research, but although marine plants are rich in iodine, the common idea that the sea is especially high in iodine content as compared with the land is not supported by facts ; the earth’s crust and not the sea is " the storehouse of iodine." In this respect it should be noted that in the prepara- tion of salts from natural brines iodine is largely lost, especially in refined salt. In one analysis four dif- ferent commercial salts were found to contain no iodine at all. A knowledge of this distribution of iodine in nature is important in reference to its occurrence in animal tissues. Diseased tissues, it seems, have a special affinity for iodine, possibly due to a local acidosis in the inflammatory areas. The effect of iodine on plant growth depends on -the dosage used, on the species of the plant, and on the medium to which the iodine is added. There is an optimum dosage which varies from plant to plant to get the best yield in experimental plots. Some plants, especially the beets, are much more tolerant to big doses. This has, of course, a big economic importance, for it has been shown that by iodine- manuring the total sugar yield from beet can be increased by a third. In the metabolism of animals it is very difficult to distinguish between the direct action of iodine and the indirect action through the thyroid secretion. On large animals the effects of iodine on growth appear to give varying experimental results. In three tests at Iowa the administration of potassium iodide was followed by a definite increase in rate of growth, but certain experiments in Aberdeen gave negative results. In children certain tests carried out in goitre areas show improvement in growth, but the very fact that these results occurred in goitre areas suggests that iodine intake was defi- cient before it was experimentally supplemented. The importance of iodine in development is indicated in the well-known experiments with tadpoles. Meta- morphosis in the amphibian depends, under normal conditions, upon the thyroid secretion, and it seems that iodine produces its effects in virtue of the fact that it is an essential constituent of a compound which is normally elaborated in the thyroid. Recent work on the effect of iodine on certain tissues and organs in the normal subject has brought to light some significant facts. Iodine stimulates intestinal movements, and in excessive doses causes diarrhoea. When administered by the mouth potassium iodide causes a rapid rise in the iodine content of the blood, while the effects of iodine on the skin, whether by external application or internal administration in large doses, are well known. These results have possibly more of a therapeutic than a physiological interest; the effects produced by iodine on the sex organs come into- both of these categories. It has long been believed that iodine causes injury to the sex glands, but the dosage in most of the recent experiments which appear to support this view is exceedingly high ; no injurious effects occur with small or moderate dosage. These facts have a definite importance in relation to the iodine requirements of animals and man. As far as the former are concerned information is meagre. It is comparatively easy to calculate the iodine intake in animals, and this can be shown in certain experiments to vary in a ratio of from 1 to 6 parts per 1000 millions, comparing the iodine intake with the body-weight. Whether this is adequate or not is not known. In the human subject the minimum amount required daily for an adult male is calculated at 15 microgrammes (mil- lionths of a gramme), and for a child about 50 micro- grammes. The dosage necessary to prevent goitre is higher, and the lower physiological limit is placed at about 100 microgrammes per day. The relation of iodine to thyroid secretion and goitre receives close attention in the report. We have concentrated here on some of the other aspects of iodine in agricultural and domestic economy. The importance of mineral balance in dietetics and the part played by iodine in the equilibrium of the animal organism are becoming increasingly recognised. As with vitamins on the organic side, so with iodine on the inorganic side, the infinitely little counts for much. ____ MINOR LESIONS OF THE FEET. THE minor lesions of the feet are responsible for such an amount of disability among all classes, and for so much loss of time and inefficiency in many occupations, that the medical practitioner should be sufficiently acquainted with the possibilities of local treatment to know when his patient may be referred to a qualified chiropodist with benefit. Comparatively few members of our profession are aware of the change which is occurring in the practice of chiropody in this country. The chiropodist has in the past been regarded, often with justification, as a quack who, for commercial reasons, usually combined his occupation with that of hairdressing, and it is true that a considerable number of this type of inadequately qualified practitioner still remains. The Incorporated Society of Chiropodists has, however, as its main object the control of the practice of the profession, and aims at placing it upon a strictly ethical basis ; the Society has inaugurated schools of chiropody at various centres, each with its attached " Foot Hospital " in which the students acquire their practical training. The courses in these schools reach a high standard and extend over one to two years. The diploma of the Society, by which the fully educated chiropodist may be recognised, is granted both to successful students of the schools and to others on passing a suitable test. To this end a reliable text-book is essential. The third edition of " Practical Chiropody," written by Mr. E. G. V. Runting,l has just reached us. Mr. Runting has contributed a useful article on his subject to our columns (THE LANCET, 1927, i., 51), and those who recall its message and desire to learn more details of the type of treatment the chiropodist is capable of carrying out should consult his book. The author has great experience of the subject and has avoided dogmatism where there is room for controversy ; the scientific side of chiropody is admittedly in its infancy, and it is too early to adopt stereotyped treatments for many pathological conditions of the foot. The chapter upon the standardisation of terms will be found especially useful, the system given being that adopted at the Foot Hospital. ____ SYNTHETIC CHEMISTRY 1828-1928. THE centenary of the synthesis of urea by Fr. Wöhler in 1828 was very modestly commemorated by the Biochemical Society at their October meeting held at Cambridge. Sir F. Gowland Hopkins gave an address, in which he referred to the very slow appreciation of the importance of the nature of the discovery, either by the leaders of chemical thought at the time or by the writers of text-books in the immediately succeeding period. It is, perhaps, fair to state, as does Gowland Hopkins in the fuller discourse published in the current Biochemical Journal, that Wohler himself, although he refers to the synthesis as " merkwurdig," did not see that he had begun to attack " vitalism." It certainly was noteworthy that an attempt to prepare ammonium cyanate by heating the potassium salt with ammonium carbonate should yield a substance which had been known for about 50 years as an important constituent of urine. In 1836, J. Duma " who had met Wohler in Paris three years before, had developed so much insight into the problem of " vitali-.m " as to write in. my belief there are no substances which, in any peculiar sense, are to be called organic. I visualise in organised beings only very slowly working forms of apparatus which act upon materials at the moment of their genesis and thus produce from a very few elements very various organic compounds." 1 Practical Chiropody. Third edition. By E. G. V. Runting, F.I.S. Ch., Founder and First President of the Incorporated Society of Chiropodists. London: Faber and Gwyer, Ltd. 1928. Pp. 200. 5s.
Transcript of SYNTHETIC CHEMISTRY 1828-1928
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plants, as work at the Rowett Institute at Aberdeenhas shown. Heavily cropping the soil tends to depleteit of iodine, and manuring with either dung or arti-ficial fertilisers causes a marked loss of iodine. Theamount of iodine in fresh water and in sea water hasbeen the object of much research, but although marine plants are rich in iodine, the common idea that thesea is especially high in iodine content as comparedwith the land is not supported by facts ; the earth’scrust and not the sea is " the storehouse of iodine."In this respect it should be noted that in the prepara-tion of salts from natural brines iodine is largely lost,especially in refined salt. In one analysis four dif-ferent commercial salts were found to contain noiodine at all. A knowledge of this distribution ofiodine in nature is important in reference to itsoccurrence in animal tissues. Diseased tissues, itseems, have a special affinity for iodine, possibly dueto a local acidosis in the inflammatory areas.The effect of iodine on plant growth depends on
-the dosage used, on the species of the plant, and onthe medium to which the iodine is added. There isan optimum dosage which varies from plant to plantto get the best yield in experimental plots. Someplants, especially the beets, are much more tolerant to big doses. This has, of course, a big economicimportance, for it has been shown that by iodine-manuring the total sugar yield from beet can beincreased by a third. In the metabolism of animalsit is very difficult to distinguish between the directaction of iodine and the indirect action through thethyroid secretion. On large animals the effects ofiodine on growth appear to give varying experimentalresults. In three tests at Iowa the administrationof potassium iodide was followed by a definite increasein rate of growth, but certain experiments in Aberdeengave negative results. In children certain testscarried out in goitre areas show improvement ingrowth, but the very fact that these results occurredin goitre areas suggests that iodine intake was defi-cient before it was experimentally supplemented.The importance of iodine in development is indicatedin the well-known experiments with tadpoles. Meta-morphosis in the amphibian depends, under normalconditions, upon the thyroid secretion, and it seemsthat iodine produces its effects in virtue of the factthat it is an essential constituent of a compoundwhich is normally elaborated in the thyroid. Recentwork on the effect of iodine on certain tissues andorgans in the normal subject has brought to lightsome significant facts. Iodine stimulates intestinal movements, and in excessive doses causes diarrhoea. When administered by the mouth potassium iodidecauses a rapid rise in the iodine content of the blood,while the effects of iodine on the skin, whether byexternal application or internal administration in
large doses, are well known. These results havepossibly more of a therapeutic than a physiologicalinterest; the effects produced by iodine on the sexorgans come into- both of these categories. It haslong been believed that iodine causes injury to thesex glands, but the dosage in most of the recentexperiments which appear to support this view isexceedingly high ; no injurious effects occur with
small or moderate dosage. These facts have a definiteimportance in relation to the iodine requirements ofanimals and man. As far as the former are concernedinformation is meagre. It is comparatively easy tocalculate the iodine intake in animals, and this canbe shown in certain experiments to vary in a ratioof from 1 to 6 parts per 1000 millions, comparing theiodine intake with the body-weight. Whether this is adequate or not is not known. In the humansubject the minimum amount required daily for anadult male is calculated at 15 microgrammes (mil-lionths of a gramme), and for a child about 50 micro-grammes. The dosage necessary to prevent goitreis higher, and the lower physiological limit is placedat about 100 microgrammes per day.The relation of iodine to thyroid secretion and
goitre receives close attention in the report. Wehave concentrated here on some of the other aspectsof iodine in agricultural and domestic economy.
The importance of mineral balance in dietetics andthe part played by iodine in the equilibrium of theanimal organism are becoming increasingly recognised.As with vitamins on the organic side, so with iodineon the inorganic side, the infinitely little counts formuch.
____
MINOR LESIONS OF THE FEET.THE minor lesions of the feet are responsible for
such an amount of disability among all classes, andfor so much loss of time and inefficiency in manyoccupations, that the medical practitioner should besufficiently acquainted with the possibilities oflocal treatment to know when his patient maybe referred to a qualified chiropodist with benefit.Comparatively few members of our profession are
aware of the change which is occurring in the practiceof chiropody in this country. The chiropodist has inthe past been regarded, often with justification, as aquack who, for commercial reasons, usually combinedhis occupation with that of hairdressing, and it is truethat a considerable number of this type of inadequatelyqualified practitioner still remains. The IncorporatedSociety of Chiropodists has, however, as its main objectthe control of the practice of the profession, and aimsat placing it upon a strictly ethical basis ; the Societyhas inaugurated schools of chiropody at variouscentres, each with its attached " Foot Hospital " inwhich the students acquire their practical training.The courses in these schools reach a high standardand extend over one to two years. The diploma of theSociety, by which the fully educated chiropodist maybe recognised, is granted both to successful studentsof the schools and to others on passing a suitable test.To this end a reliable text-book is essential. The thirdedition of " Practical Chiropody," written by Mr.E. G. V. Runting,l has just reached us. Mr. Runtinghas contributed a useful article on his subject to ourcolumns (THE LANCET, 1927, i., 51), and those whorecall its message and desire to learn more details ofthe type of treatment the chiropodist is capable ofcarrying out should consult his book. The author hasgreat experience of the subject and has avoideddogmatism where there is room for controversy ; thescientific side of chiropody is admittedly in its infancy,and it is too early to adopt stereotyped treatments formany pathological conditions of the foot. The chapterupon the standardisation of terms will be foundespecially useful, the system given being that adoptedat the Foot Hospital.
____
SYNTHETIC CHEMISTRY 1828-1928.
THE centenary of the synthesis of urea by Fr. Wöhlerin 1828 was very modestly commemorated by theBiochemical Society at their October meeting held atCambridge. Sir F. Gowland Hopkins gave an address,in which he referred to the very slow appreciation ofthe importance of the nature of the discovery, eitherby the leaders of chemical thought at the time or bythe writers of text-books in the immediately succeedingperiod. It is, perhaps, fair to state, as does GowlandHopkins in the fuller discourse published in the currentBiochemical Journal, that Wohler himself, althoughhe refers to the synthesis as " merkwurdig," did notsee that he had begun to attack " vitalism." Itcertainly was noteworthy that an attempt to prepareammonium cyanate by heating the potassium salt withammonium carbonate should yield a substance whichhad been known for about 50 years as an importantconstituent of urine. In 1836, J. Duma " who hadmet Wohler in Paris three years before, had developedso much insight into the problem of " vitali-.m " as towrite in. my belief there are no substances which,in any peculiar sense, are to be called organic. Ivisualise in organised beings only very slowly workingforms of apparatus which act upon materials at themoment of their genesis and thus produce from a veryfew elements very various organic compounds."
1 Practical Chiropody. Third edition. By E. G. V. Runting,F.I.S. Ch., Founder and First President of the IncorporatedSociety of Chiropodists. London: Faber and Gwyer, Ltd.1928. Pp. 200. 5s.
349
At the present time vast numbers of organic com-pounds have been synthesised; in fact, the late
Raphael Meldola wrote a fairly thick volume of shortdescriptions of syntheses of such compounds, andsince his untimely death in 1916 many more haveyielded to laboratory arts. It must not, however, bethought that great cause for jubilation exists. Naturedoes all her organic chemistry within a very smallrange of temperature and with very mild reagents, withvery limited variations of pH. Fusions with alkali,treatment with powerful dehydrating reagents, andsealed tube reactions under pressure are unknown toher. In plain fact, the syntheses of the laboratory arealmost invariably performed in a manner which woulddestroy the apparatus in which Nature works.Furthermore, Nature has retained the secret ofoptical activity, leaving to Art the perpetual dis-appointment of synthesising racemic forms only. Thegreat value of syntheses, a value far outweighing thecommercial advantages of cheap and pure products, isthe great light which a not too violent method ofartificial formation throws on the constitution of thesubstance formed and on its affinities with otherbodies. It is true that certain well-known vegetableproducts, such as alizirin, the colouring matter ofmadder, and indigo, can now be prepared morecheaply and satisfactorily in chemical works than inthe field, but this is largely due to the fact that a newscientific industry has competed with and conqueredan old empirical one. It is conceivable that thebotanist, the biochemist, and the agriculturist mayyet find means whereby the leisurely and cosmicallyeconomical methods of Nature may again, and thistime successfully, be brought into competition withArt, and synthetic chemistry be directed with evengreater vigour to its task of discovering absolutelynew compounds, which may be, as many have been,powerful agents against disease or useful in the arts.From the synthesis of urea to that of thyroxin abouta century elapsed. What will the next hundred yearsbring ? -
GANGLIA.
GANGLIA are frequently seen in any surgical out-patient department, but either they have not beenstudied so carefully and thoroughly as are otherless common lesions or their pathology presentsexceptional difficulty. ’At any rate, numerous specu-lations liave been made concerning their pathology,origin, and nature and discarded from time totime. In an exhaustive study recently published,1Dr. Louis Carp and Dr. Arthur Stout point out thata ganglion has been called a " knot of tissue " con-taining " mucoid flesh " (the Hippocratic description),a retention cyst, a neoplasm or degeneration cyst ;it has also been described as due to herniation orrupture of a tendon sheath. They themselves believethat ganglia arise by a mucinous degeneration ofthe coliagenous fibrils in the fibrous tissue of jointcapsules and tendon sheaths. They have observedunder the microscope tiny areas of degenerationwhich coalesce to form small cysts. In the walls ofthese cysts the lumen of the vessels is conspicuouslydiminished by fibrosis, and it has been suggested bysome writers that the constriction of these vesselscauses local impairment of nutrition and degenerationof the fibrous tissue of the cysts. Dr. Carp and Dr.Stout, however, consider these changes to be secondarybecause they have found healthy capillaries passingthrough areas of degeneration, giving them an
adequate supply of blood. They make no attemptto explain the cause of the mucinous degeneration.The wall of a ganglion is composed of fibrous tissueand the cavity is lined by a dense smooth, white membrane also composed of fibrous tissue, but in acondensed form. There is no epithelial lining. Thecysts do not necessarily communicate with joints ortendon spaces, but they may do so if the degenerationis severe. There is usually a chief cyst surroundedby numerous accessory cavities. Trauma has beensugge ted as a predisposing cause, but trauma in the
1 Surgery, Gynecology, and Obstetrics, 1928, xlvii., 460.
region of the wrist is a common occurrence andganglia relatively rare. A conspicuous feature in theaetiology of ganglia is their occurrence in females of-slight build between the ages of 20 and 40. In oldage ganglia are rare. The selection of the bestmethod of treatment is of great practical importance.Serious symptoms are rare, and deformity is usuallythe reason given by patients who want treatment ; 9but interference with function and weakness do occur,and pain may be present in some cases, especially-those in which a nerve is surrounded by the ganglion.Since recurrence is usually due to incomplete removal,any operation to be successful must be extensiveand often involves a prolonged and difficult dissection..For this reason, and also because ganglia sometimes.disappear spontaneously, Dr. Carp and Dr. Stoutconsider it desirable to reserve operative treatmentfor those cases which do not yield to simpler methods..They have had fair success from rupture of theganglion, either by gradual pressure or by a suddenblow, and also from aspiration of the contents followedby injection of an irritant such as tincture of iodine.Pressure should always be applied for some timeafter any non-operative treatment. When an opera-tion has to be performed a general anaesthetic shouldbe given. These conclusions are based on the lateresults of 70 cases, and will confirm the impressionsof many surgeons whose experience of the results ofoperation has not been encouraging.
THE MENINGOCOCCUS.
Cerebro-spinal fever is a disease of peculiarinterest to the clinician, the sanitarian, and thebacteriologist, all of whom should welcome thepublication of Dr. E. G. D. Murray’s monograph 1on the organism which causes it. Of the useful " greenbooks " issued by the Medical Research Council, this isthe fifth to deal with the disease. The Diplococcusintracellularis meningitidis is an obligatory parasitewhich has never been found apart from humanbeings ; in normal times it lurks among the populationof England in an almost imperceptible form, livingin a few noses and throats, generally causing nosymptoms, sometimes producing a catarrh andoccasionally a frank case of meningitis. Under certaincircumstances, the most important of which appearsto be the close aggregation of large numbers of
susceptible people, the organism rouses up, spreadswidelv through the exposed population, and causesenough cases of meningitis to constitute an epidemic.These striking epidemiological facts have been alreadylargely elucidated by bacteriological methods whichalone have made it possible to identify the carriers,.and no doubt their further explanation dependsmostly on our knowledge of the organism on the onehand, and the reaction of the body on the other.Dr. Murray has brought together all that is knownabout the organism ; his references to clinical medicine,pathology, and hygiene are only incidental, thoughhis last two chapters-on human infection and on.diagnosis-are of immediate sanitary importance..He reviews in order the morphology, physiology,virulence, toxin production, and immunity reactions,.and in his closing paragraphs points out how thehabitual neglect to study the biology of bacteria forits own sake has sadly hampered progress along-purely utilitarian lines. It is impossible to noticeall the points of interest which arise-the wholeshould be read as a coherent tale. Most are ofspecific moment, but scattered about are manyitems of wider importance-e.g., the possibility ofdrying the organism without killing it, and theexaltation of virulence which may be produced quitequickly by growing it in leucocyte extracts.
Dr. Murray’s book will be very useful to workingbacteriologists, but it will not escape criticism invarious directions. It contains no summaries forhurried people, and it is not always easy to make out
1 Medical Research Council Special Report Series, No. 124.H.M. Stationery Office. Price 3s 6d. pp. 142.
