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NOVEMBER 20, 1926.

An AddressENTITLED

THROUGH THE MAZE OF MEDICINE.Delivered at the Scientific Medical Conference, University

of Rochester, N. Y., on Oct. 26th, 1926,BY ANDREW BALFOUR, C.B., C.M.G.,

M.D. EDIN.,DIRECTOR OF THE LONDON SCHOOL OF HYGIENE AND

TROPICAL MEDICINE.

AT the eleventh hour Dr. Rhees asked me if I wouldcome to Rochester and deliver an address in the placeof Dr. Charles Martin, Director of the Lister Institute,who, unfortunately, was unable to visit America. Faced Iby this honourable yet onerous task, I found myself I

somewhat in a dilemma, for pen had to be put topaper when crossing the Atlantic, when I would bedivorced from nearly all works of reference. It wasclear that a strictly scientific paper was an impossi-bility, for there was no means of verifying facts andfigures. However. the Atlantic itself furnished a

clue, for the thought of a great ship like the Leviathanthreading its way, under guidance, through a mazeof waters to a desired haven led me to think of thestudent of medicine. Not that I would for a momentcompare the average medical student to the Leviathan.The latter is very rapid, luxurious, presumably outto make money, indeed, many things a medicalstudent should not be, but just as a ship on hermaiden voyage leaves a home port, traversescharted waters, encounters buffetings and difficulties,yet eventually gains her objective, so the medicalstudent ventures forth upon what we may call themaze of medicine and usually, despite trials andtroubles, chiefly in the shape of examinations, makesgood and is let loose upon a confiding public.

A MEDICAL EDUCATION.

It, therefore, occurred to me that it might be wellto trace his wanderings through the maze. The mazeitself has been the subject of careful considerationand criticism by Sir George Newman, who, in his twomasterly studies, " Some Notes on Medical Educationin England," published in 1918, and " RecentAdvances in Medical Education in England," whichappeared in 1923, has said practically all that can besaid upon the matter. The second memorandum isa brilliant and fascinating piece of work, philosophicand humane, yet practical and inspiring, wherein awealth of illustration is employed. It is, indeed, aclassic utterance. It would be presumptuous, as

well as useless, for me to intrude into Newman’s ’field but, as he views the maze from the standpoint Iof an expert and administrator, I think it may be ofinterest in the first place to try to stand in the shoesof the medical student and see how he, with hislimited outlook, is impressed by his new surroundings.It is not easy to do so, at least for anyone who wasa medical student many years ago, for it is hard torecapture the elusive past, and, in addition, theinexorable process of evolution has imposed changesand advances of which one is not fully cognisant.In the second place, while Newman has in yet

another brochure pressed for the permeation of themedical curriculum with the preventive idea, and hasindicated on broad lines how this should be accom-plished, there would seem to be room for discussing insome little detail this new guide-rope which it is desiredto introduce into the maze, this guiding principlewhich is intended to lead the student of to-day andto-morrow towards an objective, differing in someways from that upon which the ambition of hispredecessors has been set, an objective designed tomake him not only a better doctor, but a more usefulcitizen, and to enlist his brains and knowledge in theservice of the State, as a guardian of the publichealth.

Now it is a strange thing how little the lay publicrealise all that is comprised in a medical education.I fancy the parents who pay the fees are betteracquainted with its magnitude, if not its complexities,than anyone else. Years ago at Khartoum, in theSudan, Lord Kitchener paid a visit to the GordonMemorial College, and along with Mr. (now Sir James)Currie I had an interview with him. He declaredhimself satisfied with what was being done at theWellcome Tropical Research Laboratories of the SudanGovernment, and asked if I thought the nativestudents were profiting by the education given themat the College which was, in fact, really a secondaryschool. I said I thought they had made very goodprogress and had been well grounded. " Very well,"he remarked, " I want you to go a stage further andturn out native medical officers. I give you two yearsin which to do it." " What you ask is impossible,"I replied. " The word impossible is not in myvocabulary," he said, very emphatically. " Nor,as a rule, Sir, is it in mine," I ventured to retort, " butin this case what you ask is impossible. Do you knowwhat course these boys would have to go through ? "" Tell me," he said, and I told him in detail and couldsee the surprise come into his impassive countenance.It would take too long to recount our conversation,which had its humorous side. Suffice to say thatLord Kitchener abandoned his idea for the time being.However, as you may know, in memory of that greatsoldier and organiser there now exists a medical schoolin Khartoum where the Sudanese are trained to bedoctors, but the curriculum is not limited to two years.At present, however, I am not so much concerned

with the length of the medical curriculum, which wouldseem to have reached its limit, as with its object andits general effect upon the student who, greatly daringif he only knew it, plunges sometimes unheedinglyand thoughtlessly into res medicae. I find myself alittle at a loss in speaking to you, for I am not fullyacquainted with the details of medical education inthe United. States. True, I have studied Flexner’sbook, I have also read " Martin Arrowsmith," andpondered over it, but I take it that Sinclair Lewis isscarcely an authority on medical education, althoughhe can portray effectively certain aspects of it.

Hence, in dealing with the maze of medicine Ihave in mind rather the course of studies pursuedby the medical students in the schools and universitiesof Great Britain, but believe that this does not greatlydiffer from that followed in the best centres of medicaleducation in this country, while, from the point ofview of the effect of his studies on the student, humannature, I take it, is much the same all the world over,and in any case there is a measure of kinship betweenthe sons of the United States and those of GreatBritain which suggests that their viewpoints cannotbe vastly dissimilar. Speaking generally, it may besaid that in both countries the medical student passesthrough the maze, guidpd on broad lines by the Deanof the Faculty, in details by his teachers, in manythings by his fellow-seekers after knowledge, andthat, at present, the link which binds together, oftenvery loosely, the various subjects he has to study,is of a biological nature. His outlook is coloured bybiclogy, using the word in its widest sense, althoughhe himself may not be conscious of it.

THE STUDENT’S FIRST IMPRESSIONS.For the purposes of our argument let us take the

young student who has done little or no biology atschool, and who, therefore, on beginning medicine,has to take up botany and zoology. He finds himselfin a new world, the world of life viewed from thestandpoint of the scientist. It is difficult for him toadjust his ideas. Not only are the terms usedstrange to him, the processes employed novel, thenew facts a revelation, but, unless his teachers arevery wise men, he sees at first everything as througha glass darkly, and is inclined to ask, "What’s theuse of all this to a doctor ? " Botany proves, as arule, more irksome than zoology. for vascular bundlesdo not appeal to him, and thA f"t.ndv of natural

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orders seems a mere waste of time. I think as arule he appreciates the value of the training intechnique in the practical work of the laboratory,but field excursions, save as an outing, are notattractive. I have often heard a student complainthat he was taught all about the insides of plantsand how to classify them, but was never told howto recognise the common trees and shrubs andflowers of his own country. This shows that themedical student tends to look upon botany, not asa means to an end, but as a well-defined subject,the cultivation of which should lead to botanicalfruits. Even though he is studying zoology alongwith it, he does not see that, as Newman says, thetwo subjects are complementary to one another.Still less does he grasp the part that botany plays inthe general scheme of his education, though it is

significant that his interest quickens when thoselowly forms of vegetable life, the bacteria, are pre-sented to him, and when he is introduced to plantswith medicinal and poisonous properties.Whether it was due to the fact that I was not well

taught, or that, having commenced the study ofmedicine at the age of 16, my intelligence was atfault, I cannot say, but I remember getting one ofthe shocks of my life at a zoological demonstrationwhen the man sitting next to me nudged me in theribs and said in a loud whisper, " That’s a humantongue! " It was not only that I was broughtunexpectedly for the first time into contact with thehuman cadaver or a portion of it, though I rememberthat my imagination ran riot about that tongueand its whilom possessor, but that I suddenly realisedthere was a close link between man and the brutecreation. The human tongue, being comparativelylarge, was being used to demonstrate certain featuresof a rabbit’s tongue, and ever since I have thoughtthat while, as a rule, comparative anatomy is madeto pave the way towards human anatomy, it wouldbe well at times to reverse the process in a student’sfirst year and, by making use of human parts, to teachthe great lesson of evolution and relationship.How important it is at this stage for the student

to become familiar with Darwin’s " Origin ofSpecies " ! Without it, even when well taught, heis apt to miss the true significance of his zoologicalstudies, and, as Milton has it, " in wandering mazeslost" perceive no end. Says Newman, "if themedical man be not a biologist he is nothing," buttoo often he gets little chance of becoming a truebiologist, being wearied by " types." He passes fromthe earth-worm to the snail, from the snail to thefrog, from the frog to the skate and dog-fish, thenceto the rabbit, and is apt to regard such as a delimitedstage in his progress to an examination, rather thanas an integral part of his life’s work. True, thingsare changing for the better, but even yet the studenttends to grope blindly, content to meet the immediatefuture.

THE FIRST YEAR SUBJECTS FUNDAMENTAL.The teaching of physics, apart from biophysics,

is nowadays very largely a function of the secondaryschool. I will not discuss the student’s attitudetowards it, but hope later to consider how it may bemade the means of impressing the preventive ideaupon his plastic mind. There are medical studentswho take kindly to chemistry. They are usually menwith a mathematical bent, to whom the exactitudeof the science appeals. To many chemistry is summedup in the word " stinks." In the past I thinkchemistry more than any subject has been divorcedfrom medicine. It is true the student comes acrosssubstances which figure in the Pharmacopoeia or areused as poisons, and rejoices accordingly. It is truehe learns something of chemistry in industrial lifeand hears something about the chemical aspect oftrade hazards, but, until recently, he was not taughtto realise that chemistry in some form or other willfollow him all through his course. If biology is thefoundation of medicine, as Newman asserts, chemistryis one of its main props. Happy the first-year

student who has, as at Edinburgh, a course of medicalchemistry provided for him, arranged as a preparationfor a future course of physiological chemistry. Toooften the student views chemistry as a stumbling-block. His one desire is to get through with it andtake up " real " subjects, as he calls them. To acertain extent attracted by the practical work whichhas something of the occult in it, he yet shies atequations as a horse at a gate, and resolves that, ifonly he passes, he will relegate the subject to the limboof forgotten things. It may be that this is no longerthe case, but it was so in my day, and there wereI think, few students who understood that the subjectsof their first year-chemistry, physics, and biology-were fundamentals, and represented the platform onwhich had to be built that training in science, inscientific thought and method, which is essential ifmedicine is to be other than mere empiricism andquackery.

TRAINING IN ANATONIY.

Anatomy comes next, and in all probability theeffect of the first contact of the student with thedissecting-room is never wholly effaced. Some mentremble without the door, others cf tougher fibrebetray no trepidation, but though, ere long, studentsmay, as at Cambridge, speak lightly of "themeaters," to many the anatomy rooms mean theirfirst contact with death. For a space there is a,

mystery about the sheeted figures, so stiff and silent,and though it passes. I am inclined to think hisexperience of them gives the " medico " his firstsense of power. He begins to imagine that he isset apart for special work. When he dons his apronand takes in hand the scalpel he feels the rubicon ispassed, and that he has in some measure become apriest of the craft of healing.As the wonders of the human body are revealed

anatomy becomes so engrossing that the student isapt to become unduly immersed in details. He hasgot hold of facts, and for a time their memorisingseems to him a satisfactory and excellent thing.There is danger of the anatomy room becoming a merevalley, both of dry bones and dry facts with noquickening influence, nothing to link it to otherbranches of study. Newman, Keith, and others havedealt fully with this peril and its remedy, but it maynot be easy to wean the student from the habit,easily acquired, of amassing facts and forgettingprinciples. Does the study of anatomy coarsen themind ? In some cases this would seem to be the case,for a time at least. Familiarity with the dead maybreed some contempt for the living, but there arecounteracting influences, and, to any student worthhis salt, the marvels revealed by dissection shouldeventually bring a sense of humility and admiration,coupled possibly with wonder and pity that so

delicate a mechanism as the human body is doomedto destruction and decay.

PHYSIOLOGY THE INSTITUTES OF MEDICINE.I have always thought that my old teacher, William

Rutherford, " Bilirubin " as he was nicknamed afterthe bile-pigment he discovered, was in the right whenhe insisted on calling his subject the " Institutes ofMedicine " instead of physiology. If physiology werealways so regarded and taught the student would findthis part of the maze easier than he usually does, andwould perceive light ahead. If the maze be properlyconstituted there should not only be light ahead, buta certain refulgence behind him. proceeding fromthose parts of the maze he has already traversed.All the subjects he has been through should, as itwere, unite in casting a beam of light on physiology,for here the student, now familiar with the dead body,contrasts it with the living. I think that apart fromthe histological side of the study, no subject of thecourse is at first so bewildering as physiology. Thereare so many side lines. The student has not only tograsp the mechanism and aim of the functions of thebody as a whole, but, let us hope, with some recollec-tion of physics in his mind, he must apply that subjectto life and movement and consider also various

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electrical reactions of the tissues. Physiologicalchemistry, or, as nowadays we may term it,biochemistry, which includes metabolism andendocrinology, will soon remind him that the timespent on chemistry, especially in its organic aspects,has not been wasted. Biomechanics will againremind him of his physics and will couple his physicalwith his anatomical knowledge. The physiology ofthe special senses will take his mind back to theanatomy theatre and the dissecting-room, and willonce more show him how a knowledge of physics isessential to the proper understanding of such delicatemechanisms as, let us say, the eye and the ear, whilehis excursions into the comparatively young butall-important science of psychology should makehim realise that while all thought processes centrein the brain which he has sliced and teased andsectioned, there is something intangible and elusivewhich, fortunately for himself, he can now liken tothe wireless, and which may give him a wider concep-tion of man’s meaning and future. Lastly, when heapplies his physiological knowledge in the laboratoryupon the frog, upon the mammalia, there will dawnupon him a sense of the marvellous scheme of life,of its completeness as well as of its variety, of itsinter-relations, of its correlations, of the smoothnessand elasticity with which the body functions, of itsextreme delicacy, of its marvellous strength, of itsrecuperative power.Physiology is like a central chamber in the maze

wherein all the other tracts he has been exploitingmeet and mingle, and from which other tracts emerge.At first, confused by its very spaciousness, the studentstruggles to grasp its significance, but once he hasgot to grips with it his future is, or should be, secure,for, from this rallying ground, light beams alongevery tortuous out-going channel of the maze ofmedicine and more especially penetrates those whichhear the designation " clinical."

THE PRINCIPLES OF PATHOLOGY.

Bugs " and " Drugs "

are what the irreverentstudent sometimes calls the two subjects to which Ihe is introduced when anatomy and physiology arebehind him. It is rather significant that he classespathology under " bugs," giving prominence to itsbacteriological side. If he imagines, however, thatbacteria and bacterial processes dominate the wholeof pathology he will have a rude awakening. SirArthur Keith, in a recent lecture, recommended thestudent to pay an occasional visit to the post-mortemroom while studying anatomy. It was sage advice,but most students never see what have been calledthe " doctor’s failures," those tragic forms from thewards. until they have begun to wander through thatpart of the maze, a very large and intricate part, wherethey learn about tiny visible and invisible foes ofman and discover what a mess disease can make ofthe form and functions of the wonderful mechanismof which they themselves are examples. The student,as a rule, takes kindly to this

" science of morbidprocesses," as Newman aptly names it. For onething, the bacteria are interesting and tangible.Most folk have a little of the farmer or hunter aboutthem, relies of ancient days and forbears, and so it ispleasant to cultivate cocci and bacilli and to searchfor them in the blood and organs of some haplessguinea-pig or rat. For another the student renewshis acquaintance with the pathogenic protozoa,parasitic worms, and noxious insects, is reminded oftheir complex life-cycles, and begins to understandhow important they are, especially in the romanticdomain of tropical medicine. Yet again he sees

under the microscope sections of tissues with whichhe is familiar, altered sometimes out of all knowledge,while in the cadav he witnesses the gross manifesta-tions of disease. If his course is well ordered, however,he will also be given an opportunity of studying

pathology in the living. Prof. Dean, of Cambridge,has said with truth, " Pathology, if it is to be theuseful reality it ought to be to the student andgraduate, must be learned in the wards, as well as in

the post-mortem room and the laboratory." This,therefore, is a very interesting stage in the journeythrough the maze, for the student comes in contactfor the first time with the living patient, and he alsohandles and sees the human shell from which the vitalspark has but recently fled.

PREPARATION FOR CLINICAL WORK.It is true that if, like a wise man, he has taken

some more of Sir Arthur Keith’s advice, he will havealready attended an operation or two in order toextend his anatomical experiences, but that is not quitethe same thing as standing by the bedside of a patientand noting, perhaps, how yellow is his skin and thatthere is an ominous fullness in the right hypochon-drium below the costal margin. This first incursioninto wards and dead house cannot fail to leave itsmark on the student’s mind. Well it is for him, ifnow, and later when his clinical work commences,the humane side of him comes uppermost. Thereis a type, hard and keenly scientific, which comes tolook upon the patient as a case, even as a museumspecimen. This type may make a good pathologist,but he will never be a great doctor. No man can bea successful clinician if he is void of sympathy, andif he does not consider his client both from thepsychical and the physical standpoint.One cannot follow this section of the maze through-

out all its ramifications, but the student will find onceagain that chemistry comes into the picture, and thatfrom the diseases of the lower animals he may learnmuch that has a bearing on human pathology." Drugs," in the old sense of the word, have gone outof fashion. We live in a world of tablets, of vaccinesand sera, of endocrine preparations, of diet restric-tions. We have harnessed the sun to our own uses,and even imitate the lord of light. Electricity andradium are drugs nowadays, and there are variousother developments of which the student must havemore than a smattering. Thirty or forty years agohe found the materia medica part of the maze simpleenough but more than a trifle dull. Now he certainlycannot complain for lack of variety and presumablyhe appreciates the fact that both pharmacology andtherapeutics are linked up with his previous studies,and most strongly linked by the biological chain.And so, gradually, in some ways almost insensiblvprepared for it, the student reaches the most fascinat-ing but the most intricate part of the maze ofmedicine. In some of the British schools he passesfirst of all through a kind of intercepting chamber,devoted to purposes of coordination, a place wherehe gets a breather before his final plunge, can takestock of his surroundings, and of his past, and notonly have a refresher course in anatomy, physiology,and pathology, as applied to medicine and surgery,but undergo a short period of training in clinicalmethods, including case-taking, to fit him for hisimmediate duties. In my day at Edinburgh thistook the form of what were called clinical tutorials,which were held in the evening, and the studentsfound them most helpful, even though they did notprecede, but were concurrent with, the work in thewards. Now the idea has undergone great expansionand modification, and it must be infinitely easier forthe student to approach the bedside. In the olddays some of us, young and callous, suddenly plungedinto surgical wards as dressers in our second year ofthe maze, felt uncomfortably like humbugs, and,though possibly we did no great harm, it is unlikelyeither we or our cases derived much benefit from thecontact.At this stage the student, unless warned, is apt to

forget that he is no longer dealing with disease as aseparate entity, but with disease which has invadednot only the human organism, but a personality.He must be taught to think not in terms of thedisease but of his patient, and for that purpose hemust realise that the person, now sick, is a productof his past environment, which has probably beencomplex, and that the patient, himself complex, may,or probably will, so modify the disease which has laid

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hold upon him that its bold outlines as recalled frompathological studies will no longer be apparent.If he does not grasp the significance of this truth, andstill more the fact that vital processes control drugactions, he will certainly go astray, especially whenhe starts to treat his cases. In this part of the mazehe will, so to speak, bump up against both in-patientsand out-patients, and he will also learn the value ofnursing and of the efficient nurse. Not a few medicalstudents regard the staff nurse with respectful awesecond only to that in which they hold the " chief."The same feeling, however, does not usually extendto the probationer.What of surgery ? I remember it was quite a

considerable time before I plucked up courage to goand see an operation, even though I hail fromScotland and had paid a hospital fee ! EventuallyI selected for my first plunge an enucleation of theeyeball, which I witnessed (save the mark) from aback seat in a large theatre. I take it quite a fewstudents suffer from a similar timidity. What savedme was an amputation of the leg, which had perforceto be performed on an accident case during a crowdedout-patient clinic from which I could not escape, andwhat helped me through the ordeal, for such it seemed,was my knowledge of anatomy. Here is an illustra-tion of another way in which the value of linkingsubjects together can be manifest. Pray pardonthese personal reminiscences. I make use of themonly to give point to the arguments advanced.

In connexion with his surgical course the studentis now trained in the nature and use of anaestheticsin a manner which did not previously exist. To manya man this must come as a boon and a blessing. Itis no use, indeed, it is fatal, to leave any branch ofpractical work to the student’s own initiative. Thereare some who have none, there are others in whomdiffidence masters initiative, there are yet others whoare the slaves of slackness.

THE MAZE THICKENS.It is now that the student discovers that he must

begin to reason in a way he has never done before.He finds himself up against most difficult problems,and very soon discovers that guessing is dangerous.He has to proceed along definite lines of inquiry andexclusion, and, as he does so, he will find again howall his stores of knowledge can now be drawn uponas occasion requires, and if he has the necessarybreadth of vision it will be apparent to him why hehas had to struggle so long in the intricacies of themaze, and he will begin to feel that not far off he willround the last corner and be free. He is fortunateif, once he has made some progress in his clinicalstudies, he gets a chance to put precept and observa-tion into practice as, say, in dispensary practice undersupervision, where he comes into contact with hispatients in their own homes, and learns more ofhuman nature, its makeshifts, trials, sorrows, vices,and virtues, than he can in any hospital ward or out-patient department. There, also, perhaps, for thefirst time he will get some inkling of social problemsand realise the need for safeguarding the publichealth. Dispensary practice or no, he will have tovisit the humble homes when he attends obstetriccases, and it may be said that almost a new worldopens to him when he enters, perhaps fearfully,that part of the maze which traverses the fields ofmidwifery and gynaecology. To many a male studentthis is a difficult and not altogether congenial part ofhis wanderings, but possibly that is because therehas, in the past, been a comparative failure in themethods of teaching it. How this may be remediedis set forth by Newman in the second of his treatisesand, as I must return, though briefly, to the subjecta little later, I need not here say more. My ownexperience is so limited that it is scarcely fittingthat I should enlarge upon the theme.

I think most students enjoy the short course inmedica! jurisprudence. There is an element of thedramatic in it, with tragedy well to the fore. Quiteapart from its medical aspects, which can be rendered

very impressive if linked up with the work of apolice surgeon, the student, now probably approachingman’s estate, has an opportunity of learning somethingabout the machinery of law, and criminal law isinfinitely more interesting than public health legis-lation, concerning which at this time he also gets aninkling.He is fortunate if he gets more than an inkling

into the huge subject of preventive medicine.However, even at this late stage in his medicalcareer, he may have an opportunity of grasping thecardinal facts that curative and preventive medicinecannot be divorced from one another, and that, asa practitioner, he will have duties both towards hispatients and the State which it is imperative that heshould fulfil to the best of his ability.

THE STUDY OF SPECIAL SUBJECTS.No good object will be served by talking about the

study of special subjects, amongst which one doesnot class diseases of children, for that should be anintegral part of the medical curriculum. In practiceperhaps half the doctor’s patients will be " sick kids,"and as, for the elucidation of their complaints,it is necessary to know how to approach and handlethem, and as there are maladies peculiar to childhood,and as ordinary diseases assume in children formsdifferent from those they present in the adult, and asthe doctor must treat the patient and not the disease,it seems criminal to grant a medical degree to anyman who has not been instructed in pediatrics.Furthermore, the contact with child life is for thestudent a useful, and let us hope, usually a beneficialexperience which will stand him in good stead inyears to come.As he emerges into the open ready for cap and

gown, degree, or diploma, relieved, but with a newsense of responsibility, it will be to his advantageif he realises he has only escaped from one maze toenter another, one more spacious, perhaps, but nonethe less puzzling, and it is a maze likely to last himall his life if that be passed in the practice of hisprofession. Yet before he enters it I think it wouldbe well if he were conducted into an annexe to theoriginal maze with the words " History of Medicine "

placed above it, an annexe where he might profitablyspend a little time in study and from which he wouldcome a wiser and more humble man, able and willingto subscribe to the words of England’s last greatPoet Laureate :-

" Yet I doubt not through the ages one increasingpurpose runs

And the thoughts of men are widened with theprocess of the suns."

THE PREVENTIVE IDEA AND ITS APPLICATIONS.

, You will remember how, in the second place, it

was proposed to discuss how Sir George Newman’sidea of permeating the medical curriculum with thepreventive idea could best be carried into effect.In the short time at my disposal I can, of course,merely touch lightly on the subject which is oneof considerable complexity and difficulty. Newman’splea has found support both in Great Britain and theUnited States, but, in one respect, the youngercountry has gone further than the older, for, in theperson of Prof. W. S. Leathers, the VanderbiltUniversity, Nashville, Tennessee, aided by a grantfrom the Rockefeller Foundation, has appointed some-one charged with the duty of superintending thepermeation. I had an opportunity of talking things overwith Prof. Leathers when he was in London, and it wasclear that all would not be plain sailing. The medicalstudent of to-day has so much both to ingest and todigest that it is very easy to overload the curriculumand precipitate a crisis. Again, in some instances wehave to do with " blind leaders of the blind." Theteachers themselves are not fully versed in preventiveprinciples. How Prof. Leathers has faced hisproblem I do not know. I only wish he were hereto tell us. I think the difficulty of inculcating thepreventive idea is easier at the beginning of the

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medical course than during its later stages. In this

part of the maze one can see here and there strandsof another guide-rope than that marked biological.In other words, at present, in subjects like physics,chemistry, and zoology the instructors draw some oftheir examples from matters closely concerned withthe public health. Many of the principles theyenunciate play a part in preventive medicine, andsometimes all that may be required is to lay stressupon them from the standpoint of the hygienist,remembering that under the title hygenist the studentand exponent of sociology and eugenics is included.The teacher of physics can easily direct the student’smind along preventive grooves, or, to keep to ouroriginal simile, see that he grasps the new guide-ropein the maze. When he teaches the use of meteoro-logical instruments he can discourse on the prophy-lactic uses of climate, when he expounds certainlaws of humidity and air movement he can remindhis hearers of what adequate ventilation means tohealth, especially, perhaps, in certain industries,when he touches upon hydraulics he can find usefulillustrations from engineering practice in water-supplyand sewage disposal. During the study of electricityhe may cite the effects of electrical disturbance uponwhite men in the tropics, and the beneficial effect ofthunderstorms. Under dynamics he can consider thehuman body as a machine and show how certainexercises will ward off certain deformities. Theseare but a few suggestions. It is evident that theycan be multiplied but never ad nauseam, for anysound argument which will impress upon the studentthus early the value of prevention of disease is to thegood, and, in any case, it is likely to make his physicsmore attractive and his study of public health easierwhen he comes to it.

Chemistry, both inorganic and organic, offers a

good opportunity to the apostle of preventivemedicine. Take the dangerous trades and the useof poisonous substances in various kinds of industries.A disquisition on the prevention of lead poisoningcan be made full of interest and at the same timefurnish chemical instruction of value. A subjectlike your tetra-ethyl-lead problem in the States mightbe turned into a useful lesson. Excellent prophy-lactic ideas can, as they say in the States, be

" scld "

the student during a consideration of the chemistryof air and water. The mercurials and - organicarsenicals can be made to furnish a sermon on theprevention of venereal disease, though, perhaps, thisis dangerous ground over which to lead a student inhis first year of medicine. Yet if the lay public areinstructed, why not the youthful disciple of Escula-pius ? The chemistry of carbon conjures up coaland smoke, and at once smoke-prevention and allthe lessons to be learned from it give zest and lifeto the lecture. These are very obvious directions,probably to some extent exploited at present, butthere are other avenues. What of the lime salts andquestions of dental hygiene and the warding off ofrickets ? What of preservatives in food ? Whatof nitrogen in sewage sludge ? What of chemicalsubstances, like Schweinfurth’s green and

"

stoxal,"used in the destruction of insect vectors of disease ?It is, of course, inexpedient to give lengthy dis-quisitions on these subjects. They should be used asan electric torch is used to illuminate and to showwhat lies ahead. It is like the art of the impres-sionist, but, if properly practised, it should not failof its effect.

In zoology it is easy to find themes, but in a moreindirect way, perhaps, that is to say by a carefulselection of types during the study of which referencecan be made to their importance in medical workand indications given of how their ill-effects can beobviated. As examples take under the protozoa,the amoebas; under the insects, the mosquito ;under the helminths, the hookworm. As a matter offact, there is at Edinburgh University, for the third-year student, a special short course in medicalentomology and parasitology, which affords abundantscope for talking about prevention. But in zoology

there are other ways of spreading the gospel of pre-vention. The rabbit is one of the types always inevidence, and there can be no harm in telling thestudent about the discovery of tularaemia, and howits spread may possibly be checked. His interest inthe rodent is likely to be quickened thereby.Similarly, if he dissects a mollusc like a mussel ora snail, he should be told, on the one hand, howedible shell-fish may spread disease and how theycan be safeguarded, and on the other he may learnthe important r6le of certain water snails in somehelminthic maladies, and how snails can be slain withcopper sulphate, if indeed he has not already learnedthis fact during his chemical studies.At this early stage the thing must be carefully

done, or the student will be crammed with ill-digestedfacts, and will become the prey of that half-knowledgewhich is so dangerous. As a forgotten poet oncesaid :-"Be ignorance thy choice where knowledge leads to woe."

Botany does not lend itself so fully to the il’iustrationof the preventive idea, but lessons can be drawnfrom it, even apart from those suggested by thebacteria which, indeed, are better left until pathologyis tackled. So far as tropical hygiene is concerned,botanical knowledge has its uses. There is thequestion of the flora associated with the prevalenceof the tsetse-fly, there is the planting of eucalyptusand sunflower to dry swampy ground, there is ther61e of the Bromelias and other epiphytes as mosquitonurseries, there is the question of mosquitoes breedingin the tops of coconut palms and the action of azolla,lemna, bladder-wort, and other aquatic plants onculicine life and activity. The hygienic uses of certaingrasses can be discussed along with the Graminacese,reterence may be made to the old practice in India ofclearing water with the fruits of Strychnos potatoruyn,the value of the water chestnut in averting faminemay be cited. The edible fungi will suggest themeasures to be taken to avoid the poisonous andinedible, while the transpiration and respiration of

plants and the shade properties of certain trees maybring up the subject of aboriculture in towns. Again,is there not the question of the traveller’s palm andthe baobab with their reservoirs of drinking-water,the barrel cactus of Mexico, and the wonderfulNarra fruit of Damaraland which saves the Hottentotthere from extinction.Anatomy can easily be turned into a quarry from

which ideas on preventive medicine can be delvedand shaped. There is the question of posture andall that it implies. Once again the lime salts cometo the fore, and with them and also apart from themthe hygiene of dentition. The skin makes a goodtext, both as regards Besredka’s new ideas on immunityand with reference to light and pigment, while chestexpansion, the prevention of fibrositis and otherforms of rheumatism, the prophylactic value of certainforms of exercise upon muscles, the guarding againsteyestrain, and hundreds of other questions hingeupon anatomy.What is true of anatomy is, of course, even more

true of physiology. There is the whole vast subjectof industrial hygiene in which physiology plays a

prominent, indeed a pre-eminent, part, and to whichthe student’s attention may from time to time bedirected with advantage ; there are the physiologicalproblems associated with the hygiene of infancy,childhood, puberty, and adolescence. The preventiver6le of hormones, the functions of vitamins,especially in warding off the deficiency diseases, thequestion of protecting the heart, lungs, and kidneysfrom strain, all merit attention. Then there are

preventive lessons to be drawn from the study of thehigher functions and of the special organs of sense.And so on ; it would take much too long a time ,evento mention all the possibilities, but I cannot helpthinking that, despite the wealth of examples, it mayperhaps prove more difficult to permeate thephysiology course with the preventive idea than anyother branch of study, and this largely because the

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average physiologist is so immersed in the fascinationof his subject that he is apt to regard it as the acme ofexistence, not as a means to an end. Moreover, thetype of mind which takes to physiology is rarely thatwhich is attracted by the wider issues of public health,though there are notable exceptions. If, however,the physiologist will look upon his subject, as, in somemeasure, a combination of the Institutes of Medicinewith the Institutes of Hygiene he will have unrivalledopportunities for reminding his class that there is aLatin maxim which says Qui non prohibet quodprohibere potest, assentire videtur. " He who doesnot prevent what he has power to prevent, is regardedas assenting to it."

THE CLUES.From this part of the maze onwards it is easy to

place the new guide-rope in position. The studyof bacteriology teaches many lessons in preven-tion on which we need not dilate. Is not immunityand all it predicates the very essence ofprophylaxis ? P During his pathology studies thestudent can be led to see, not only how important itis to prevent disease altogether, but to grapple withit at the outset. The history of cancer may beadduced to point the moral. Again, the study ofintra-uterine pathology will pave the way for furtherconceptions later in the curriculum, while he can alsobe made to see in many instances how the patho-logical processes of old age may be held in abeyance.Preventive measures in the case of comparativepathology may be cited to good effect, consideringthat so many parasites and diseases of animals aretransmissible to man. Once more the hygiene ofindustry comes into the picture and, indeed, on everyside lie lessons ready for use.No longer can anyone say that materia medica and

therapeutics are the handmaidens of curative medicinealone. They have now a much wider application.Indeed, pharmacology nowadays is as much concernedwith the prevention as with the cure of disease. Weknow that the administration of certain drugs canand does prevent the development of a malady, thevirus of which has been implanted in the humanbody. We know that timely exposure to sun andfresh air is a protective measure of great importance.Psychotherapy is best employed as a form of mentalhygiene, while vaccines and sera are, generallyspeaking, more valuable as prophylactic than as

curative agents.What better example of preventive medicine can

there be than the Pasteur method for rabies and itsrecent application to the dog ?

Sanitas sanitatis, omnia sanitas, owe see how theslogan can and should sound through the whole mazeof medicine. As the student passes to his clinicalstudies it will become intensified, and, to change themetaphor, he will grasp the new guide-rope with afirmer grip, though still clinging on one side to hisbiological leading strings.

This address would double in length were I toconsider all the ways in which the preventive ideamay permeate general medicine, surgery, midwifery,gynaecology, pediatrics, diseases of the skin, and ofthe other special sense organs, mental diseases andeven anaesthetics, for is there not a technique toprevent chloroform poisoning ? Much of Sir GeorgeNewman’s pregnant suggestion has yet to be workedout in detail. Its application will not be simple.It will call for patience and perseverance. I am veryconscious of the fact that I have not been able todeal with it in the way it demands. Yet I hope that,at least, I have succeeded in showing in the first placehow arduous, yet how engrossing, is the progressthrough the maze of medicine, and in the second placehow, here in the University of Rochester, as elsewhere,it were well to reinforce the biological guide-rope inthat maze by one leading step by step, yet ever moredirectly, to that conception of the prevention ofdisease which is becoming, if it has not already become,the lodestar of the physician, the hygienist, and theresearch worker alike. When once this doctrine is

established, and not till then, it will be possible toassert that we are doing our best to preach and putinto practice a belief founded on that wise saying ofancient Greece, where long ago certain basic principleswere clearly recognised :-

"Without health life is not life, life is lifeless.’

An Address[ABRIDGED]

ON A

HALF-CENTURY’S PROGRESS IN

OPHTHALMOLOGY.

Being the Presidential Address delivered to the Sectionof Ophthalmology of the Royal Society of

Medicine on Oct. 8th, 1926,BY ERNEST CLARKE, C.V.O., F.R.C.S. ENG.,CONSULTING SURGEON, CENTRAL LONDON OPHTHALMIC

HOSPITAL.

[Mr. Ernest Clarke began with a warm testimonialto the learning and merits as a teacher of Mr. WarenTay at Moorfields, and then passed in rapid reviewthe influence on ophthalmic surgery produced by theintroduction of antiseptics and of local anaesthetics,pointing out the danger of the latter which in allayingpain might mask the symptom most disturbing tothe subject so that the cause of the trouble is notinquired into. He proceeded to speak on :-]

EYESTRAIN AND CYCLOPLEGIA.

Eyestrain had been recognised and was styled" asthenopia " and practically the only symptomallocated to it was headache. In 1892 I publisheda book on " Eyestrain," which was very well receivedand reviewed. I was inspired to write it by the workof Gould, of Philadelphia, and I shall ever be mostgrateful for undertaking this work as it entailedreading every published book on refraction, andDonder’s " Classical Treatise " became my daily com-panion. Gradually eyestrain has been taking a moreprominent place in ophthalmology and generalmedicine. We now know that there is probably nofunctional nerve trouble that may not be caused orpartly caused by eyestrain ; that it enters as a secondor third partner in innumerable complaints, andthat by preventing it we may indefinitely postponeepileptoid attacks, migraine, recurrent iritis, and

possibly delay or postpone the appearance of glaucomaand cataract. We know that eyestrain is more

likely to be present with small errors and that insensitive patients 1/8 D. may make all the differencebetween happiness and content, or discomfort andunfitness. In certain individuals eyestrain may beone of the frictions of life, and a waste of nerve energy ;just as friction is a waste in mechanics.... Thiswasting is very often small, but it is going on duringall the waking hours when eyestrain is present andmay be imperceptible-that is, no definite symptomssuch as headache may indicate its presence, hence itis most insidious. This waste lowers the resistingpower to disease both locally and generally, so thatthe individual exposed to some infection which heought to be able to withstand succumbs because hisfighting power has been lessened. As in these dayspreventive medicine holds a very high place, thepossibility of the presence of eyestrain should alwaysbe borne in mind.

There are some who are preaching that cyclo-plegics are not necessary in estimating the refractionof the eye, but speaking to you with the experienceof a life’s work I would warn you not to listen to them.Most people under 40 years of age and some under 50do not, and cannot, relax their accommodationcompletely so that you cannot get down to the" bed rock " of the real condition of the eye. Donders