874 MULTIPLE PERIPHERAL NEURITIS.

they then do not produce sufficient enzymes to supplythem with the simple products necessary for theirgrowth. These experiments confirm the othersmentioned above as to the primary necessity of asupply of oxygen if decomposition is to take place.It will be appreciated that these experiments and theresults of the systematic examinations of unsoundtins have an important practical bearing upon canningproblems. They illustrate how very complex are theprocesses at work, and how far removed is the wholesubject from the simple views which are generallyaccepted. The Report, it will be gathered, is mainlyconcerned with spoilage conditions, and does notdiscuss the relationship of canned foods to outbreaksof food poisoning ; but it is perhaps worth mentioningthat none of the recognised food-poisoning organisms- salmonella strains or B. botulinus-were presentalthough looked for in every tin.

OVERCROWDING AND TUBERCULOSIS.Dr. Andrew Trimble, chief tuberculosis officer of

Belfast, has just issued a comprehensive and well-arranged annual report for the year ending March 31st,1922, which shows a definite decline in death-ratefrom the disease. The number of new patientsexamined during the year was 1703, as compared with2121 in 1921 and 2529 in 1920. Of these 1014 werefound to be tuberculous and 703 non-tuberculous, while173 were

" suspect." These figures include 207transfers from patients formerly only suspect to thegroups of the tuberculous or non-tuberculous. Asregards the forms of tuberculosis, there were 340 malesand 422 females in the pulmonary group, 41 malesand 79 females in the glandular group, 34 males and46 females in the osseous group, 18 males and 15females in the abdominal group, and 10 males and9 females in the remaining groups. These figures showa slight falling off in pulmonary tuberculosis, whichwas only 75 per cent. of the total, as compared with78 per cent. and 82 per cent. in the two precedingyears. In addition to examination of new patientsthere were 22,319 re-attendances of old patients atthe various institutes, as compared with 21,436 in theprevious year. As regards the forms of treatment,1413 patients received treatment at the dispensary,3493 received domiciliary treatment, and 344 receivedinstitutional treatment. Dr. Trimble emphasises theimportance of a frequent review of cases receivingdomiciliary treatment.The report deals at length with the evidence avail-

able on the subject of infection. The general conclusionis that 41 per cent. admitted personal association withtuberculosis amongst other members of their families.In many cases the report states that " whole familieshave been wiped out by the disease." Figures are

. given showing the large proportion of tuberculouspatients sleeping in the same bedroom with otherpersons, and even in the same bed. No less than437 patients slept with one other person, 240 with twoothers, 53 with three others, and 8 with four others.The home conditions of patients wer8 classified as

follows : exceptionally good 4, very good 28, good 138,average 627, bad 143, very bad 41, exceptionally bad 8.The proportion of cases from the different wards inthe city.show a ratio ranging from 5-9 per 1000 inSmithfield Ward and 4-4 in Falls Ward to 16 inWindsor Ward and 1-5 in Duncairn Ward.

Dr. Trimble adds that the open-air school atGraymount continues in successful operation. Theschool is intended for children living in contact withpersons suffering from tuberculosis, who should beseparated from infection and have their educationprovided as well as good nourishment. There is atGraymount also a hospital for osseous and non-

pulmonary forms of tuberculosis, with 50 beds, ofwhich 47 are now occupied, but the tuberculosis officerreports that at least 200 beds should be provided andthat after-treatment should be pursued at the seaside.

Annotations.

MULTIPLE PERIPHERAL NEURITIS.

" No quid nimis."

THE presidential address delivered before theSection of Neurology of the Royal Society of Medicineby Dr. Wilfred Harris, and published in the presentissue of THE LANCET, is devoted to a consideration ofthe less common varieties of polyneuritis. Familiaritywith the somewhat hackneyed forms produced by theabsorption of alcohol, say, or of lead, only serves toaccentuate the large lacunae in our aetiological andtherapeutic knowledge in respect of the rarer types,some of which, for that matter, are not particularlyrare. Where motor and sensory symptoms dominatethe clinical picture the case is likely to come under thecare of a neurologist, or at least a neurological opinionwill probably be called for ; yet Dr. Harris indicatesclearly in his valuable address how frequently aneuritic or polyneuritic syndrome supervenes in thecourse of diseases-malignant, febrile, infective,haemic—with which the general physician is moreimmediately concerned, and gives one or two illustra-tions of the affection as it occurs in cases that belongto the groups of industrial and of tropical disease.Nor is the catalogue to be regarded as closed. We donot know that industrial development will not bringin its train additional examples of toxic affection ofthe peripheral nerves ; nor should we be surprised ifwith advances in the study of tropical disease newvarieties of polyneuritis are recognised and described.The subject, in short, is one which calls for intensiveresearch by experts of different specialties workingin collaboration. Herein lies the special importanceof Dr. Harris’s comprehensive study.Adopting a fourfold aetiological classification, Dr.

Harris divides polyneuritis into varieties produced bythe action of external poisons, of autotoxins, of infec-tive and of cachectic states respectively, and thefactors are indeed sufficiently numerous when setdown in a list. Even so, cases are met with in practicethat do not seem to be accounted for by any of theseknown agents, while in other instances the action ofthe presumed toxin or poison is problematical orobscure. Thus Sir William Gowers used to speak ofthe case of a seamstress whose clinical condition wasone apparently of arsenical neuritis and who, it wassupposed, had gradually absorbed the poison bydrawing coloured silk threads through her teeth asshe wetted their ends for the needle. Improbable as.this may perhaps appear, still more obscure examplesof toxic absorption might be cited. We must candidlyadmit our frequent setiological ignorance even inobvious clinical instances of the disease. To Dr.Harris we are indebted for directing attention to theremarkable group of haematoporphyrinuric neuritis,especially to its occurrence where the action ofsulphonal and similar drugs can be definitely excluded.Passing allusion is made in the address to cases inwhich there is evidence of both peripheral and centralinvolvement. The term " central neuritis " wasoriginally coined by Adolf Meyer for the pathologicalcondition underlying some forms of presenile psychosis-in particular, involutional melancholia-in whichwere found changes in the myelinated fibres of thecerebrum analogous to those in the peripheral nervesin peripheral neuritis. It might with advantage beused in cases where central accompanies peripheraldisturbance, as in the psychosis of alcoholic poly-neuritis-the so-called Korsakow syndrome. Morerecently, the same expression has been employed byDr. H. H. Scott to characterise a peculiarly interest-ing disease which has been occurring in Jamaica bothin chronic and in epidemic form, and which has usuallybeen known as Jamaican peripheral neuritis. Froma painstaking clinical and pathological study, Dr.

1 Annals of Trop. Med. and Parasitology, vol. xii., October,1918.

875

Scott has come to the conclusion that the disease canbe distinguished both from beri-beri and from pellagra.It is noteworthy pathologically for changes both inperipheral nerves and neuraxis resembling those of

ordinary peripheral neuritis, and Dr. Scott admitsthat in this respect the morbid anatomy is not unlikethat of pellagra, though there is no evidence that itbelongs to the class of deficiency disorders. Further,the impressive clinioal fact seems to be definitelyestablished, that only those patients develop thedisease whose intestinal condition, as the affectionbegins, is one of constipation ; if a profuse diarrhoeaappears, as in not a few cases, the nervous symptomsfail to become prominent, or, indeed, to manifestthemselves at all. Here, then, we seem to have avariety of toxic neuritis, quite possibly of alimentaryorigin, in which central and peripheral nervous

systems alike are implicated, and which offers sugges-tive pathological analogies with pellagra, and alsowith the peculiar affection known to the neurologistas subacute combined degeneration of the spinalcord, or funicular myelitis. ’

It is obvious, we think, that by a correlation inthis fashion of morbid entities, examples of which arelikely to be met with by workers in many separatebranches of medicine, light will be thrown on someof the obscure cases narrated by Dr. Harris. Thewhole subject stands in need of further elucidation ;too commonly is a case diagnosed as polyneuritis ofunknown origin. By his timely address Dr. Harrishas awakened us from a tacit acquiescence with whatin reality constitutes a state of ignorance. Renewedattention will now be directed to a class of disease inwhich research is sure of abundant reward.

THE TREATMENT OF TUBERCULOSIS OF

THE LARYNX.

IN gauging the value of any treatment it is, ofcourse, essential that the frequency of spontaneousarrest or cure of the disease under considerationshould first be ascertained. This obvious precautionis apt to be neglected by enthusiasts ; were it alwaystaken, many a therapeutic novelty would come

to an untimely end. Tuberculosis of the larynxillustrates this point, for there are few diseases whichhave been more mercilessly tinkered at and tamperedwith, to the discomfort of the patient. The era oflocal treatment has, however, almost passed, and it isnow universally admitted that tuberculosis of thelarynx is a comparatively benign disease which isnearly always automatically arrested when the originalpulmonary disease becomes quiescent. In this con-nexion two important papers have recently beenpublished. The first is by Dr. 0. Strandberg,l of theFinsen Institute in Copenhagen. He has treated61 cases of tuberculosis of the larynx by complete arc-lamp baths, the naked patients being accommodatedin a room in which one or more arc-lamps are burning.Although most of his patients resided in their homes,coming to the Institute from time to time for a light-bath, in many cases returning to work in the intervals,50 per cent. were discharged as cured. Consideringthat all these 31 cases were complicated by pulmonarytuberculosis this result seems at first sight remarkablygood. So it is, perhaps, and of the importance of thestudies in actinotherapy conducted at the FinsenInstitute there can be no doubt. Scientific actino-therapy in tuberculosis is in its infancy, and it is to behoped that it will prove of far-reaching value. But themore valuable it is, the better can it stand searchingcriticism, and it would be well to bracket with Dr.Strandberg’s paper another by Dr. I. D. Bronfin andDr. C. Markel. 2 Their study of 200 cases of pulmonarytuberculosis showed that in as great a proportion as85 per cent. there were pathological changes in thelarynx which, in at least 63 per cent., were tuberculous.It was found that among 139 cases, undergoing little

1 Deut. med. Woch., July 14th, 1922.2 American Review of Tuberculosis, July, 1922.

or no treatment, there were only eight showing progress’if the disease, whereas 31 showed improvement, and100 were stationary. It is not, therefore, surprisingto find the authors of this paper coming to theconclusion that, though subacute or chronic tuber-culous laryngitis should be under constant observation,it does not require active treatment in the absence ofdistressing symptoms. They consider acute or per-acute laryngeal tuberculosis to be rare, and theirfindings are confirmatory of other recent writers whoare inclined to class tuberculosis of the larynx withtuberculosis of the bladder, both being comparativelybenign conditions which clear up when the primaryfocus of disease can be arrested or eliminated.

NEW VIEWS ON THE THYMUS GLAND.

RECENT knowledge acquired regarding the thymusgland seems to be but slightly spread, and clinicalliterature is full of expositions that appear to startfrom obsolete views as to the structure and functionof this gland. J. A. Hammar claims that our know-ledge of the thymus is more thorough than that ofthe majority of the organs closely related to it func-tionally, and in the Upsala Lakareforenings -b’6rhand-lingar for August, 1922, he sets forth new views as tothe morphology of the thymus and their bearing onits function.The thymus, We may recall, is an epithelial organ

issuing from the third branchial pocket, and in themajority of cases is entodermal in origin. It earlybecomes infiltrated with lymphocytes-in man as

early as towards the end of the second month of pre-natal life, at an embryonal length of about 30 mm.,the formation of the medulla begins at about a lengthof 40 mm., and the first corpuscles of Hassall appeartowards the end of the third month at about a lengthof 50 mm. By mitotic division, both of lymphocytesand the reticulum cells, and the ingrowth of connectivetissue, the organ becomes lobulated and grows rapidlyduring pre-natal life. An analysis of 80 normalthymus glands made by Dr. Hammar shows that thenumber of Hassall’s corpuscles quickly increases.They start as small formations of one or more reticulumcells, 10-25,u in diameter, increase in size, and assumea spherical shape. The majority, even in pre-natallife, do not normally attain a greater diameter than25-50c. Some, however, post-foetally may reach500.. The author insists that the thymus is not atransitory organ, but persists and functions even inold age. At puberty, however, its parenchymabegins to be reduced-" age involution." The turningpoint in the existence of the organ is at the age ofpuberty (11-15 years). Up to this time, not onlydoes its size increase, but the parenchyma remainsundiminished in volume. After this time there is arapid reduction in the bulk of parenchyma in theorgan, while the interstitial tissue usually assumesthe character of adipose tissue and forms the greaterpart of the organ. The typical structure, however, isretained in principle ; the division into cortex andmedulla, mitosis of leucocytes and reticular cells,and Hassallian corpuscles remain quite up to old age,so that, notwithstanding age involution, a functioningparenchyma remains, as a rule, even in old age, andthe organ itself il’3 a factor to be reckoned withthroughout life, not only during childhood. Invarious animals, also, involution due to age begins atsexual maturity. That the sexual glands play adecisive part in the age involution is best shown bythe condition of the organ after castration. Pre-pubertal castration does not affect the thymus beforepuberty, when it allows the amount of the parenchymain the organ to remain at a higher level than thenormal.Age involution shows itself first in the cortex,

and later on the medulla undergoes a reduction.With age involution, the decrease in the number oflymphocytes is the chief cause in the diminution ofthe volume of the cortex. The thymus is, however,never found in normal condition in subjects who have