Bradshaw Lecture ON THE CAUSES OF DISEASE.

NOVEMBER 10, 1917. than this is necessary to constitute health. A with much increased blood pressure, another with compensated mitral disease, and a third with glycosuria may all perform their functions easily and unconsciously, but they are not healthy and would be rightly refused for life assurance. The changed anatomy and function of organ and tissue are of paramount importance as well as the man’s feelings and present abilities. But in this connexion we are at once confronted with two difficulties. First, there is no such thing as a standard man, as no two people even of the same race or same family are exactly alike ; but we can without difficulty imagine an average man who is a mean between others varying but little in structure and function. The second difficulty is that of advancing years, for after reaching a state of maturity a man’s tissues and functions change and decline. Now, I should be sorry to include these changes as disease, to imagine that all of us over 50 years of age are in a state of disease. These changes are natural processes, like the falling of the leaves in autumn, and may be defined as those changes found on an average at any particular age in a particular race ; it is partly on these normal average changes that tables of expectation of life are constructed. Abnormal changes due to age are, of course, those that occur years before they occur in the average man-the early whitening of the hair, early degeneration of blood-vessels, early changes in nerve tissue, and so on. These two difficulties set aside, I think we may safelydefine disease as that condition of an individual in which there is, apart from normal age changes, a harmful change of the structures or functions or sensations usually found in the average man of any particular race. This definition will include neurasthenia and hysteria amongst diseases, but will not, of course, include malingering. more man

Bradshaw Lecture ON

THE

CAUSES

OF DISEASE.

Delivered before the Royal College of Physicians of London Nov. 8th, 1917,

BY ERNEST S. LIEUTENANT-COLONEL,

on

REYNOLDS, M.D.LOND., F.R.C.P., CLINICAL

R.A.M.C. (T.); PROFESSOR

OF

MEDICINE

IN THE UNIVERSITY OF MANCHESTER; SENIOR PHYSICIAN TO THE MANCHESTER ROYAL INFIRMARY.

MR. PRESIDENT AND GENTLEMEN,-I am deeply sensible of the honour which has been done me in asking me to give the lecture to perpetuate the memory of Dr. William Wood Bradshaw. Some of the details of his life were given by my predecessor, Dr. Newton Pitt, in 1910, who describes him as cultivated, refined, but somewhat eccentric. He must have been much appreciated by his contemporaries, for he was granted a degree without examination by the University of Oxford in 1847, was elected a Fellow of the Royal College of Surgeons of England in 1854, and a Member of this College in 1859. INTRODUCTORY. I often think that benefactors who endow lectureships must possess a grim sense of humour, for they make at least one person once a year come to a block in the busy traffic of medical practice and cause him to think and, worse still, to put his thoughts into cold, relentless print. In the strenuous times in which we live at present a complete block is impossible, and as a result one’s thoughts are constantly jostled ; and this must be my excuse for the many imperfections of this lecture, in which I have found it beyond my powers to reach the high standard set me by my predecessors. I have chosen for this lecture the old but none the less important subject, the Causes of Disease. 1 shall probably have nothing new to say, but in the exploration of the many new forests into which modern medicine has led us, with its many new names and many new methods, it is well to avoid not being able to see wood for trees. If the money expended and the labour involved in the administration of the National Insurance Act had been used to combat causes instead of effects, for my part I think it would have been ultimately of greater good to the community. If causes were more carefully considered there would not be the discreditable evidence so often given by members of our profession in the Law Courts, especially in cases under the Workmen’s Compensation Act. If causes were more carefully weighed we should not have the ultra-specialist assigning the majority of diseases to causes peculiar to his specialty, the neurologist treating a sciatica really due to an impacted uterine fibroid tumour, the gynaecologist or the nasal surgeon performing operations on neurotic patients the seat of whose troubles is really in the brain; nor the abdominal surgeon operating for gallstones when the patient is suffering from periodic bilious vomiting due to migraine ; nor hear of successive operations on another patient on the colon, appendix, duodenum, and gall-bladder to cure pains due to the gastric crises of tabes dorsalis ; nor advising the removal of a supposed gastric cancer because the patient was suffering from the wastihg of Graves’s disease-all instances which have recently come to my own notice. My thoughts have been specially directed to this subject of causation by trying to discover the cause of that very distressing and prevalent affection, disseminated sclerosis, of which more anon, and also by reading a recent small volume by our colleague, Dr. Mercier, entitled"Causation and Belief," a book, if I may say so, of excellent merit, and, of course, of much clarity and infinite wit, and which, I think, should be read by every medical man. DEFINITION OF. DISEASE. We must first have some definitions. I have been surprised to find no definition of disease which seems It is obviously the converse of health, defined by Professor Adami as a state customary to a series of individuals in which they perform their functions easily and unconsciously. But much No. 4915

satisfactory.

which

is

DEFINITION

OF

CAUSE.

As regards Cause, the best definitions I know are those of Dr. Mercier, whose views I will put as shortly as possible. He first defines Effeot as a change conneoted with a preceding action, or an unchange connected with an accom-

action (such as the unchanging steady movement of an engine) on the thing changed or unchanged. A Result is the changed state of a thing on which the effect has been produced. Endocarditis of the mitral valve is the effect of the action of germs on the valve ; mitral stenosis is the result. A Cause is the action or cessation of action connected with a sequent change or accompanying unchange in the thing acted on. He then makes a strong point about the difference between cause and Condition. The latter is a passive state of or about the thing cted on by a cause and material to the effect. It may be a favouring conditionwhere more of an effect will be produced by a cause if the favouring condition is present; or a necessary condition where an extra effect or an earlier effect is produced when the necessary condition is present. Dr. Mercier points out that age, sex, race, time of year, and climate are frequently put down as causes of disease. But these are not actions but are passive states and aretherefore not causes. The age of 60 years, the female sex, the negro race, the winter, the climate of Uganda are not causes of disease, but they are conditions in which certain actions especially or only occur and are therefore favouring or necessary to the effect produced. Strictly speaking, this is correct and in the close investigation of causes must be fully allowed for. But in a wider sense condition may be for convenience included in all the necessary circumstances precedent to an effect produced and in this sense Dr. Mercier himself recognises the term in his chapter on the causes of death. METHODS OF ASCERTAINING CAUSES. We must now consider shortly the methods of ascertaining The five canons of inductive logic put forward by causes. John Stuart Mill Dr. Mercier clearly shows not only to be unsatisfactory but often useless and often absurd and in their place he gives 12 methods which are worth quoting :—

panying

1. Instant sequence of the effect on the action. 2. Subsumption of the case in hand under a general law. 3. Assimilation of the case in hand to a known case of causation. 4. Association of the action with the effect when other material action can be excluded. 5. Association when the association is of proved constancy. -

T

704 6. Association when, though inconstant, the association is In professional life coincidences are common ; we all have frequent than casual concurrence will account for. I I runs " of particular cases, or.cases from particular districts 7. Association when, though itself inconstant, the ass ’ or from particular doctors. ciated effect has constant peculiarities. Four years ago I remember three cases of myasthenia 8. Concurrent and proportional variation of the action ar d gravis at one time in the Manchester Royal Infirmary, two the effect. of them being under my own care. About the same time I 9. Common rarity of the action and the effect. 10. Correspondence of a quality in the effect with a qualii y saw three cases of Bence-Jones’s albumosuria within a few months. Recently I saw two cases of unrelated Thomsen’s in the agent. 11. Coincidence in space of an action or a condition wit h disease in one week, and the next week a case with all the usual signs of Thomsen’s disease which had apparently the effect. come on after shell shock, but in whom I found no family 12. Coincidence in time of the action with the effect. history. A few weeks ago late one night I wrote a medicoInstances of these methods, are of course given by D legal report on a case of death from pulmonary embolism Mercier, but all of us can quite easily find instances i noccurring in a man whose left tibia had been fractured bya medicine, and can see the value of the methods in ascertair - failing stone while he was at work; the first case I saw the ing the causes of disease. In many diseases in which th e next morning was an officer with a pulmonary embolism exact cause is not known, such as measles, Hodgkin’s diseas e from a fractured right tibia due to gunshot. or tetany, we may make shrewd guesses by the use of thes Oqincidenae or Causal Connexion ? methods. But in other diseases, such as true tic-douloureus In these cases of pure coincidence I am told by a spleno-medullary leukasmia or sclerodermia, we have nc .sufficient knowledge of antecedents and no similarities wit I mathematical friend that there is no formula which applies other conditions, so that at present no cause can even b eto them. Percentage is no test. Suppose the same 1000 persons to start at different times of each day from the guessed at. East-end of London, walking at different speeds, and another the in to cause Of ascertain ’ trying many fallacies found 1000 to start from the West-end ; the number of times one of the commonest is the post koa propter fcoc argument each year that John Smith (coming from the East) This may be and often is perfectly true in the sense that ; cause precedes an effect. But to be true a connexion mus t will meet Thomas Brown (coming from the West) at be shown to be established by one of the methods of causatioi l St. Paul’s may be quite considerable, and if no causal con"between the action that is ante and the effect which i I nexion can be shown will be pure coincidences. But William from the East may meet Mary coming from the West post." But it cannot be too strongly asserted that merl coming at Paul’s St. only on two occasions, although each one passes man strains does establish A him not causation. sequence that spot each day, but if the two meetings were pre. arranged self while lifting a weight; he continues his work, perhaps with some difficulty; two days afterwards he commence; , by themselves or their friends the meeting is an act of causawith pneumonia and dies, and a claim for compensation i; , tion. Similarly in disease; we sometimes find epileptics who mitral stenosis, but these are two very common affecput forward, and it is often most difficult to persuadei have tions and are certain to meet as pure coincidences in the . lawyer that there is no necessary connexion between thl same individual fairly frequently. Trench fever is common, and the A cleans death. man ou original slight injury drains from a dye-works and gets chrome eczema and chroml so are lice on the bodies of soldiers ; and in the same way it holes on the hands. He happens to vomit the same day thai must not be necessarily assumed that lice are the sole he cleared the drains; he continues to have dyspepti( carriers or in any way the carriers of trench fever, although I have seen a very symptoms and occasional vomiting and loses flesh, and a fev they may be one method of conveyance. months after dies from a gastric cancer, and without being great number of cases of disseminated sclerosis since the able to show the slightest connexion (except mere sequence: commencement of the influenza epidemic in 1889, but one between the injury to the hands and the gastric cancerE must not assume that influenza is of necessity a cause of claim is made for the death. But it is common knowledge disseminated sclerosis. Let us take now low percentages. Late nervous affecthat legal compensation actions abound with such cases: and there is no doubt that the supposed efficacy of many tions of the tabetic or general paralytic type are said drugs is falsely based on the post hoc propter hoc argument, to occur in about 7 per cent. of all persons who have had syphilis. Yet no one doubts the causal connexion for two the real healer being nature. reasons: first, that the observations are being constantly Coincidence. corroborated; and, secondly, that it conforms to the methods Another fallacy, which is of such enormous importance of ascertaining causes. In the epidemic of arsenical beer that I think it worth while to dwell on, is that of pure poisoning in the Manchester district in 1890 I had about 1200 coincidence. It depends, of course, principally on the fact cases of arsenic poisoning under my care; amongst them I had " long ago pointed out by Bacon that there is in the human 16 cases of herpes; only 1-3 per cent. Was this a pure comind a peculiar tendency to dwell on affirmative and to incidence or was there a causal connexion? The latter overlook negative instances(Fowler’s ’’Inductive Logic"). "certainly, for as a matter of fact, knowing that others had To my mind this is the explanation of most of the curiosities found herpes in arsenical poisoning, it was the presence of of telepathy, thought reading, I I dreams coming true," and herpes which made me look for the arsenic. Actual pain of psychic research, and not unfrequently is the explanation and fine tremors are very rarely indeed found in leadof things being falsely ascribed as causes of disease. The poisoning. Personally I have only seen these symptoms in number of coincidences in life is actually enormous, but two or three cases ; but I have no doubt that there is a relatively is only a very minute fraction of the myriads of causal connexion, because others have seen them, though thoughts, dreams, and sensations which continuously crowd rarely ; and, knowing that lead will cause motor paralysis, Think of the innumerable it is not unreasonable to suppose that it may rarely cause our daily life awake and asleep. incidents which fall on the eye and the ear in a walk through pain and tremor. Perforating ulcer of the foot I have only the city; to the great majorty of these we pay no heed, but seen, I think, twice in diabetes mellitus, but I have no doubt immediately one incident fits in with another a coincidence it is secondary to the neuritis and changes in the sensory is established ; we fix on this and remember it and very roots of the spinal cord found in that disease. Some years often call it, instead of a pure coincidence, an act of ago I published in Brain an account of four families, causation. Let me give some examples of pure coincidence. in two or more members of which disseminated sclerosis Since then I have had no fresh instances of On the morning of Feb. 14th, 1876, Elisha Gray registered occurred. his patent for a telephone at the Washington Patent Ofce; familial incidence in this disease, and, although the disease is common, hardly any other observer has noted it as a on the afternoon of the same day Graham Bell, quite indein every way, registered his patent for a telephone possible family affection ; therefore- I am inclined to believe pendently in the same office. A few years ago a friend of mine was my cases were more or less coincidences. I also published a reading Canon Gore’s book Lux Mundi "; in order to keepI note in the Britilh Medical Journal of instances in which I the back clean she picked up from a table near by the dis- had seen disseminated sclerosis and Graves’s disease in the carded paper cover of another book and put it on the one same person; here, again, no corroboration being forthshe was reading; shortly after it was found that the paper cover’s title was " The Light that Failed " by Kipling. A coming, I think I was dealing with pure coincidence. few weeks ago I casually opened a periodical lying on a hotel Diseases and Primary Causes. table and fronting me was a coloured print of Constable’s a few minutes afterwards I A a box of opened glance through any text-book of medicine will reveal an Haywain ; cigarettes and in it found a print of the same picture. enormous number of diseases with particular " names." This more

’

L .

,

,

705 it should be ; for without such large numbers of names could not carry on our personal observation of diseases For old nor could we communicate our thoughts to others, as it is I do not think that Hobbes’s definition can be too often repeated, that " a name is a word taken at pleasure to serve for a mark, which may raise in our mind a thought like some that we had before and which being pronounced to others may be to them a sign of what thought the speaker " had or had not before in his mind." (And I should like, in an aside, to say that I consider it an unwarrantable crime for old names to be altered or used in different circumstances without very full justification. 1, Cursed be he that removeth his neighbour’s landmark.") A further study of all these diseases will show, however, that the things that cause them can be narrowed down to a comparatively few classes, so that from a purely prevention point of view the number of actual diseases, considered as primary and not as regards their final effects, is similarly few. For instance, most diseases of the heart are not primary, but are the final results of some infective process ; the same thing applies to most glandular affections ; liver diseases are often circulatory or due to some poison ; very many brain affections are due to circulatory troubles, and diseases of vessels to premature old age, and so on with any other system, the skin, the kidneys, the lungs, or the spinal cord. One has only to think of the numerous diseases set up by three primary causes-alcohol, tubercle, and syphilis-to realise the truth of this. As an example of remoteness of cause and effect the following may be given. A few weeks ago I was asked to see a lady who had is

as

we

I think it may. Take the case of a man who has been " wet and had to remain in his wet clothes until he felt chilled. I am prepared to believe, until fresh evidence is forthcoming, that he may as an effect have a parenchymatous nephritis, in a pure case of which I know no evidence which connects it with a germ growth. Again, I am a firm believer in the bad effects of a "draught." The breezes of a mountain top may harm no one, but sitting in the draught from an open window is, to my mind, a pernicious habit. It not only may for the time lower resistance, but can undoubtedly, quite apart from germs, so far as evidence goes, cause facial paralysis and brachial neuritis. I have seen paralysis of muscles supplied by the external popliteal nerve so caused, and in one case a paralysis of the muscles supplied by the fifth cervical root, and I think it likely that many cases of sciatic neuritis are due to cold pure and simple.

through "

Food.-Poisoning.

Food being of prime necessity, I will consider it next. Results of improper feeding will sooner or later appear on our island. Practically each person will differ from every other in the quantity and quality of the food he takes. Some will naturally require more food than others; some will have healthy or unhealthy likes or dislikes for certain foods; others will have food idiosyncrasies ; others, according to inclination or opportunity will take too much food, others too little, and so will arise obesity (the commencement of many diseased conditions) or emaciation. Probably many abnormalities of blood pressure are due to improper feeding. Some will bolt their food, causing dyspepsia of various forms. Some may get diarrhoea, others constipation, with its many undesirable but few physicians will, I think, be prepared to recently been operated on successfully for an hour-glass effects ;the formidable and curious catalogue of the effects of stomach. But she insisted that she could not walk and I accept remained bedridden. I was told this was due to hysteria, ’, intestinal stasis as tabulated by Sir Arbuthnot Lane. From presumably post-operative. A short examination showed improper proportion of food stuffs some may develop scurvy that she was a marked example of combined postero-lateral and others (in infancy) rickets. sclerosis which had been slowly coming on for two years, Cases of poisoning will certainly occur on our island, and was a remote effect of an original gastric ulcer with liquid or solid from animal, vegetable, and mineral gaseous, subsequent alimentary disturbances and anasmia,. sources, and we must include poisoning’ from putrid foods. A HEALTHY COMMUNITY : PROBABLE DISEASES. We may concede that tobacco smoking is indulged in, and Let us suppose 1000 healthy men and 1000 healthy women, we may get various acute, and more important still chronic, each aged 20 years, free to marry, with no hereditary taint, effects from over indulgence, effects which are commoner than is supposed. Sooner or later alcohol will be put to live in a perfectly healthy island with sufficient flora distilled usually and and at once we add enormously to the taken, and fauna to maintain life, and not under a fantastic communistic government, and let us try to imagine from what number of diseases produced, with possibly also effects on the offspring. Here may also be mentioned poisoning from diseases they will suffer and from what they will die. as presumably may be the cause of Theoretically we may suppose that none of these people intrinsic sources, such will have any disease, and that they will all die aged pernicious anasmia, rheumatoid arthritis, combined posterolateral sclerosis, possibly of disseminated sclerosis, and the 100 years owing to the natural processes of age. numerous diseases resulting from altered secretions from human not as i treating beings pure practical physicians, ductless and otherwise ; some of these poisons may glands, two human beings are pieces of machinery, we know that no from germ growth, others from altered functions originate or either in feelalike functions, habits, structure, exactly and altered metabolism, two classes to be considered later. to and this so being every person responds differently ings, his surroundings, and therefore some of the inhabitants of Oeeupation. -StlJ’ess. - Metabolie Variations. our island will suffer from various affections and the ages at Our islanders must, of course, work. If we suppose the death will vary considerably. It will facilitate my supposi- work is agricultural, and if more or less evenly divided, no tions if we agree to include in our study not only the special diseases should arise therefrom. But sooner or later original 2000 inhabitants, but also the next two or three some will work less than others either from getting unduly’ generations, without, of course, any admixture from the rich or because of indolent habits. The former may become rest of the world. obese and indulgent, the latter will suffer the usual penalties’ Injuries. of underfeeding and also perhaps of depleted homes and of Injuries will inevitably occur. Of purely so-called surgical overcrowding, with their usual results to themselves and their injuries, varying from burns to fractured skulls, I need not children. Sooner or later also other industries will arise further speak. We must also include injuries due to child- which will again by degrees become more and more birth, those to the mother and those to the child, the latter specialised, and we are at once introduced to the numerous partly asphyxial but principally resulting in the many diseases of occupation about which so much excellent work types of birth palsy, and not unfrequently in some types of has been done in recent years. With increased work there will develop (partly as epilepsy and perhaps of mental deficiency. Epilepsy in adults, osteo-arthritis, and probably new growths, are often a result of competition, partly of habit and partly of mere end results of previous injuries or irritations. Cold necessity), worry, hurry and stress, often much increased and heat applied externally may, of course, cause injuries, by the tyranny of the insistent telephone and the irritawhether they result in frostbite or in burns, and it is not tion of the rushing wheel. Stress especially affects the unreasonable to call them injuries when they produce other digestive, the circulatory, and the nervous systems. The effects. Heat will cause heat syncope, and the sun will affections set going by improper or insufficient food, by cause that form of sunstroke called by Sir Patrick Manson hurried and irregular meals, by hyperchlorhydria (often, " "sun traumatism." I particularly wish to dwell for a I think, the result of worry and rush) and by constipamoment on the effect of cold. We are all, I think, pre- tion I have already touched upon. Functional affections pared to admit that "getting cold " produces a condition of the heart, tachycardia, palpitation, and actual cardiac of lowered vitality which allows certain germs to act and dilatation may result from stress. More important still, as effects occur, and in our broad use of the word cause leading to so many affections often in the end fatal, we get But apart the increased blood-pressure which in industrial communities cold would be a cause of these diseases from germs, will cold or chill cause disease ? Personally, is so enormously common and tends to early unnatural T 2

But as

.

706 not always hereditary, and no one has yet proved senility. Equally common are nervous affections, hysteria at that they are in any way caused by germs. So far as I have neurasthenia, psychasthenia, and insanity. I believe tha acute congestion of the brain may occur causing prolonge( sd been able to observe, the commonest antecedent of large numbers of malignant growths is injury, including, of rn unconsciousness or even delirium, and for my part I an us inclined to think that Graves’s disease is primarily a nervou: course, irritation. If we say for the sake of argument that it is d. a cause then we must, I think, certainly admit that maligaffection and not primarily a disease of the thyroid gland ;d nant growths will occur in our island. But there is obviously It is a difficult question to decide whether these acquired as results of stress are handed down to appear as nervous something else : everyone suffers, if not injury, then in the for it be that these results ts irritation, even if it is only the daily passage of certainly may symptoms offspring, fasces. But not everyone suffers from malignant growth ; would only appear in certain members of our community whc to are of a more nervous temperament than the others, and d the unexplained factor is either another cause, or much more that it is merely the temperament which is handed down. 1. likely some condition. So important does this seem that >f . I would urge that research workers on the etiolcgy of new Perhaps some signs in the children may be the results of

a, Such are

;s growths would do well to turn aside from the search for the living in a household where rush and stress 1- active cause and seek out the condition which allows the always occurring. One type of stress, not, I think, suffi. active cause to produce its effect. If this necessary condiis ciently dwelt on, is that caused by nursing sick relatives is tion, whatever it is, cannot occur on our island we shall through long illnesses, especially when the illness ends d have no malignant growth and the contrary. fatally. This, of course, occurs principally in women, and is one of the most potent causes of functional nervous Pa’J’asitia Diseases. }S Ce disturbance that I know. It is one of the tragedies of life I think we must assume that our island will not be free to see a woman gradually becoming more worn, more faded, from diseases. It may be conceded that it is an Jdislandparasitic and less likely to marry as the result of being tied hand and in a temperate zone, so that we have not to consider foot to another’s sick-bed; and the worst of the tragedy is those advances of modern medicine conducted often s under greatest that very often it is inevitable and none can succour her." enormous difficulties, discomfort, and danger by our We have assumed that each of our inhabitants differs from

imitation from

are

brethren in tropical countries. I am not sure that we can the other, and therefore we may further assume that each exclude flies, fleas, bugs, and lice from the fauna of the will functionate and metabolise differently. For some unknown island, however glad we should be to do so, and they may reasons these alterations in function and metabolism may act, not only as direct irritants, but as disease carriers. lead to diseased conditions. Such are obesity, diabetess Other animal parasites such as the itch insect and the various mellitus and insipidus ; gout, hyperchlorhydria, and some intestinal worms we may reasonably exclude. ci altered digestive processes, including constipation ; altered Diseases due to Mia’J’o-organisms. functions of the ductless glands, and possibly the tendencyy almost for certain secretions and excretions to form calculi. SomeWe certainly cannot exclude germs, for even in altered blood conditions, such as chlorosis and polycytheamia,, non-pathogenic states they are apparently necessary for the continued existence and for the decay of plants and animals. rubra, belong to this group. No one knows how the first germ started, but the more one Aqe. how the first germ became pathogenic the more We must now consider abnormal changes due to age. It does the subject become. I greatly regret that is permissible here to include congenital affections (apart of modern bacteriology will not allow me to ignorance from those due to injury), many being due to abnormal or arrested development. Later changes may be either general! discuss the matter as I should like, but I venture to refer to or local. General changes seem to fall more especially on the interesting address on ’’ The Nature and Degree of the circulation, leading to diseases of the heart and blood- Specific Differences amongst Bacteriagiven by Dr. the Pathological Section of the Royal Society vessels, with subsequent affections of the brain and spinal Andrewes toon Oct. 21st, 1913.1 There he points out that cord, with simple-mindedness, loss of memory, definite of Medicine mental disease, brain and cord softenings, and hasmorrhages. generic differences amongst germs are probably of great that certain small genera, such as Bacillus (I would like to draw attention at this point to senile antiquity, and BacilltM mallei, Mia’J’ococaus melitensis, are very anthracis, of from circulation in the lumbo-sacral deficiency paraplegia cord described by Sir William Gowers, and not, I think, fixed, but that other large genera, such as the streptococci, the diphtheroids and the coli-typhoid group, are very variable sufficiently recognised.) Together with these vascular and show a readiness to gain or lose their physiological must be included the granular kidney, with its changes characters under the direct influence of their environment multitudinous range of symptoms and signs. Local changes may affect many organs. Those of the hair and’that in many cases by artificial means a non-pathogenic and skin are obvious. In the nervous system I would include germ may become pathogenic and vice versa. This subject the following diseases : paralysis agitans, senile tremor, was also fully dealt with by Professor Adami in his recent 2 adult chorea, amyotrophic lateral sclerosis, progressive Croonian lectures, in which striking examples were given. is It that all on the we highly probable premises, so keep muscular atrophy, and chronic anterior poliomyelitis ; what I will as a rule, to call domestic which, say, germs, amongst mental affections certain of the incurable adolescent remain tame, but granted certain conditions of the host, insanities which rapidly pass into incurable dementia and various senile insanities. Early degenerations of ductless such as starvation, fatigue, or exposure to cold, they become wild and cause disease. Such, for instance, are probably the glands are manifested by myxoedema, and perhaps by some .1lTderococcus catarrkazis, the pneumococcus, the staphylosenile in of Addison’s the disease; early changes types the Bacillus coccus, coli, and the germ of rheumatic fever. sexual organs by an abnormal menopause, early loss of Other germs, such as the tetanus bacillus, the Bacillus sexual power in men, and by early changes in the prostate and many of the bacteria of putregland. Early changes in the eye may cause too early errors aerogenes ealvs2clatics, of refraction or affections of the lens, while changes in the faction, perhaps normally present in the soil, only become pathogenic if they are put into suitable surroundings. I am ear may set up deafness or labyrinthine vertigo or tinnitus. The important point about all these affections is that they told that there is a possible family connexion between a are absolutely incurable. In the case of myxoadema the bacillus growing in Timothy grass, through the bovine to the human tubercle bacillus. Other bacteria and protozoa may symptoms and signs can be removed by drugs, but the condi- live in perfect harmony with their hosts (such as Bacillus tion on which the symptoms depend remains the some. pestis in the rat-flea and certain protozoa in insects and ’0’MN. birds), but are highly pathogenic in man. We must now consider the question of neoplasms, and I Other micro-organisms living in the human body belong to will take Dr. Powell White’s definition that a neoplasm is anCgroups which seem to have their members closely allied, but abnormal mass of cells, tissues, or organs resembling thosein which some are non-pathogenic, others highly pathogenic, normally present but arranged atypically ; it grows at theand in which quite possibly the latter may have arisen from expense of the organism without subserving any useful {the former. Such, for instance, are certain organisms of the function. Teratomata due to faults of development will tthroat and nose closely resembling Weichselbaum’s bacillus; almost certainly occur in some of the descendants of ourand, again, the enteric group, varying from Bacillus fæcalis : original islanders, and also, one must suppose, as no two of
wonders

fascinating my

typhoid

707 as regards ultimate human suffering to tuberculosis. The more one inquires into the family history of rheumatic patients the more one is impressed with the number of families in which the parents, especially perhaps the mother, and the brothers and sisters have been affected with rheumatic fever, valvular disease of the heart, with Heredity. or with various very definite rheumatic skin chorea, The last class of possible causes of disease is heredity. affections, such as erythema nodosum, with purpura or Our 2000 persons we have supposed to be free from inherited with that called Henoch’s purpura which personally variety taint. Is it possible for any of the first generation of their I believe to be merely a manifestation of rheumatism. offspring to inherit disease conditions or tendencies owing to 7. Nervous irritability or instability. In this group we have, of the This or environment has habits the question parents ? par excellence, epilepsy, habit spasm, stammering, migraine been so fully dealt with in Professor Adami’s recent Croonian (on the sensory side), asthma, the alcoholic habit, the various lectures and decided in the affirmative, that it is almost types of neurasthenia and certain insanities, many being of unnecessary for me to touch upon it, except to say that I the curable type. 8. Tendency to abnormal age changes, thoroughly believe such inheritance may occur. And whether in which I include certain insanities of the progressive it is due to an action on the somatic plasm or the germ plasm incurable type, such as incurable adolescent insanities and is a matter of more or less indifference to the physician senile insanities ; adult chorea; Friedreich’s ataxia early or to the hygienist, and I certainly do not propose to deal and various types of myopathic paralysis, including family with what the late Sir Jonathan Hutchinson calls the logoatrophy ; and finally, and most important, the machy of Weismannism. 1 think it quite likely that alcohol peroneal by hereditary increased blood pressure with changes produced and lead poisoning, in the parent may affect the offspring. arterio-sclerosis. early Nor does it seem unreasonable to suppose that the effects Now it will be at once quite rightly argued that to call a of under-feeding or over-feeding may have their results in disease hereditary does not explain its cause. The heredity the children ; or that such infective conditions as we have is only a condition, and some of the other nine generally allowed may develop in our island should produce an hereclasses of causes have to be brought in as factors before an ditary lessened or increased immunity. And if we con- effect is produced. But the importance of heredity in detersider a few more generations we can easily see how many the future of a race is so great that it is quite metabolic and nervous diseased states may result: But I mining I think, to give it a place in my list. legitimate, shall consider hereditary disease again in a few moments. CONSIDERATION OF ENGLISH MORTALITY TABLES FOR 1913. Summary of Causes. We can now suppose that by unrestricted immigration and I have now shown how in our community of originally in the course of many generations the health and disease of healthy persons and their progeny for, say, two or three our island has reached the condition in which England is generations disease may occur, and deaths at varying ages to-day. In dealing with this we have unfortunately only may result without any contamination from the outside very imperfect statistics of morbidity. We can obtain world, and I have classified the causes of these results roughly the number of insane and the types of insanity, a into :class more cared for by the State than any other ; or the 1. Injury. 6. Abnormal metabolism. numbers and character of certain notifiable infectious 2. Food and feeding. 7. Abnormal age changes. diseases, but that is all. For other information we must 8. Neoplasms. 3. Poisons. turn to the mortality tables of the Registrar-General. These 9. Parasites. 4. Occupation. are notoriously imperfect, depending, as they do, on certi10. Heredity. 5. Stress. It goes without saying that the percentage of deaths from ficates of death, which are, I am afraid, sometimes so natural changes due to age will be much higher than in worded as to give as little information as possible. To show how little they indicate real disease incidence, only 1800 England to-day, deaths are attributed to acute rheumatic fever, which with Effects of Immigration. its sequelæ is one of the most potent causes of disease ; into the island If we now allow unrestricted immigration only 1200 to rheumatoid arthritis, another common affection ; we shall not introduce any new cause of disease, but we 2000 to syphilis ; whereas 26,000 are classed as shall much intensify at least three of our causes-namely, only syncope, merely the final cause of death of many different. stress from increased competition, parasites, and heredity. diseases. Those parasitic affections will especially act as causative But in spite of these defects the mortality tables deal agents which are of fixed types, such as syphilis, tubercle, with such large numbers that some hint, at any rate, is the exanthemata, and so on, and we shall presently see afforded of the morbid state of the community, and they are what an enormous factor the parasite is in the production therefore worth examination. I shall take the year 1913 of disease. as to exclude war conditions) and shall only give (so HEREDITARY DISEASES. approximate figures. There was a total of 500,000 deaths. The subject of hereditary diseases must be considered in Of these, 134,000 (over one-fourth) were due to infectious more detail. They can be roughly classified into eight diseases directly, and to these should really be added an groups : 1. Direct infection, of which syphilis is the one enormous number of deaths ascribed to heart, lung, kidney, example, though some, such as Hutchinson, are prepared to and nervous diseases, the primary cause of which was germ believe that tubercle may be actually conveyed into the infection. Of these 134.000, 50,000 (one-tenth of the whole 2. The possible results of extrinsic poisoning in the death-rate) were due totuberculosis in some form, 37,000 to. ovum. 10,000 to measles, 9000 to epidemic diarrhoea, parents by such agents as alcohol or lead. 3. Structural pneumonia, 6000 to influenza, and 5000 to whooping-cough. 46,000 were changes. These may be the obvious external changes, such attributed to respiratory diseases (excluding pneumonia), of as supernumerary or webbed fingers and toes, coloboma, or which 39,000 were due to bronchitis, but this is very albinism. Or they may be internal structural defects. such frequently merely a terminal phenomenon. 39,000 (nearly as found in hsemophilia, and due to cancer or other forms perhaps myo’oniacongenita and one-twelfth of the whole) were disease, 38,000 to disease of the blood-vessels, amyotonia congenita should also be included ; or latent of malignant structural defects which show themselves later as various 30,000 to diseases of the digestive system, 27,000 to nervous skin diseases-psoriasis, lichen xeroderma, urticaria, or diseases, 27,000 to heart disease, 26.000 to syncope (which is terminal phenomenon, but may include many a chilblains. For those who believe in the heredity of cancer, again valvular affections of the heart), 20,000 violent deaths, 15,000. and I think most clinicians do, the unknown latent conditions to Bright’s disease, and 12,000 to atrophy and debility (a. underlying the affection may be perhaps included in this classification of no value). There were 18,000 premature group. 4. Altered metabolism. as, for instances, gout with its births. Old age is accredited with 30,000 deaths, or oneseventeenth of the whole. numerous manifestations, of which some only may be handed As I have said, these figures give us some hint of disease down, diabetes, and obesity. 5. Idiosyncrasies to certain foods or odours. 6. Tendency to germ infection, possibly from conditions, but certainly nothing more than a hint of prime some hereditary lessened immunity. The great example of causes. For instance, three most potent prime causes have this group is, of course, tuberculosis. But I wish to take very low figures-venereal diseases, 2000 ; alcoholism, 1900 ;; this opportunity to emphasise the enormous influence of and rheumatic fever, 1770. I can understand a certain heredity on acute rheumatic fever, an influence which I dodiffidence in entering syphilis or alcohol as a prime cause not think is sufficiently pointed out. To my mind it is ofIfon a death certificate, but there seems to me to be no excuse

we may not allow that certain very fixed the germs of syphilis, measles, scarlatina, or small-pox would affect our islanders without introduction from overseas, it is reasonable to suppose that many diseased conditions due to germs may arise within.

So that

although

types such

as

’

equal importance

708 This fact is of interest, for not naming acute rheumatism, except, perhaps, that ilt form of the sclerosed patches. is even not yet sufficiently recognised how slight, especiallythough the disease has no relation to alcoholism." in children, its manifestations may be, nor that chorea inII think Dr. Williamson’s observations certainly suggest that children is for all practical purposes a sign of rheumaticthe toxic agent may be in the cerebro-spinal fluid. If we use our tables of causation of disease we can rule fever, and, finally, that the enormous preponderance oif cases of organic diseases of the heart valves is due tcout injury, food. occupation, stress, age, neoplasms, and heredity ; also all extrinsic poisons. But we cannot set aside previous acute rheumatism. It is interesting to compare my list of causes of disease intrinsic poisons, nor altered metabolisms, nor parasites with these figures, however imperfect and unsatisfactory, off growing either in the nerve tissues or forming toxins which the causes of death, to imagine how many of the 38,000) act on the nerve tissues. It was a long time before it was deaths from disease of blood-vessels were due to abnormal1 proved that acute anterior poliomyelitis was due to a germ, old age or to stress and how many to syphilis, what propor- and we do not know at the present time whether the longtion of the 30,000 ascribed to the digestive system was due to) drawn-out and peculiarly intermittent symptoms of myasthenia food and feeding, and what proportion of nervous diseasess gravis are due to germs, altered metabolisms, or intrinsic was to be attributed to germs, to stress, to abnormal old age,, poisons, the only definite effects found being lymphorrhages in the muscles and some fatty degeneration of an enlarged or to heredity. DISSEMINATED SCLEROSIS. thymus gland ; and although of recent years the Treponema has been found in the brain of general paralytics, A disease in which I have been interested for years is it seems more probable that the essential changes of this disseminated sclerosis. It is in my own personal experience affection and of tabes are due to the toxin rather than to almost the commonest of organic diseases of the nervous local growth of the parasite. system in which morbid changes can be found. It is a most Consideration of Possible Causes : Need of Research. to the also to the ; not but distressing malady, only patient, On the whole, by subsumption of the case in hand under a physician, for it comes on without any known cause, principally affects those in the full bloom of life, is no respecter general law and by assimilation of the case in hand to a of persons, and has a most crippling effect for years before itknown case of causation, it seems certain that disseminated causes death. In my own experience it is much more commoni sclerosis is caused by a poison acting on certain special in women. nerve tissues. If this is an intrinsic poison, which I am Very frequently, indeed, much more so than is generallyquite prepared to believe, it is probably either a perverted supposed, it first affects the optic nerve rather rapidly; this! internal secretion or a poison derived from the alimentary affection is generally temporary and may be followed by aLcanal, possibly as the result of constipation. In this long intermission, often lasting years. With or without this! connexion it is most important to keep in mind the postero. initial symptom sensory symptoms, often very indefinite, lateral changes found in the spinal cord in diabetes, peroccur, and rarely there may be severe pains not unlike those! nicious anaemia, and many exhausting diseases. If from a of a definite neuritis. At the same time or later there are germ, is it from the germ of some known fever, such as disorders of motion, which may be slight, like an indefinite! measles, typhoid fever, or influenza ? I think from the ataxia, or much more marked from affection of the pyramidal previous histories this can be at once answered in the tracts or of ascending nerve tracts; very rarely actual wasting negative. Or may it occur as a late result of any previous of muscle may result. A very marked feature of the disease germ infection independently of nature ? I think this should is the occurrence of intermissions and remissions, the longest also be answered in the negative, not so much because some intermission, as a rule, being between any early eye of the patients say they have never had any previous germ symptoms and the sensory and motor phenomena; so long, infection (in which they may be mistaken), but more because indeed, is this interval that unless closely questioned patients it seems to me that from analogy it is highly improbable never mention the original eye symptoms and certainly never that a disease which in spite of its many varieties has so connect them with the subsequent symptoms. very distinctive a character both clinically and pathologically can be caused by any odd germ or germs which may have Causation. previously affected the patient. It may be finally noted that Pathologically the lesions are very widespread and their the disease resembles in many respects those nervous locality points to something distributed by the lymph in the affections caused by syphilis, although we know that syphilis vessels or cerebro-spinal channels, or by blood in the blood- is not its cause, nor do the pathological changes resemble vessels, and probably more immediately by the former. The those produced by syphilis. But in its early affection of the cause, whatever it is, has a predilection for the medullary eyes, its widespread distribution of lesions, its intermissions sheath and the neuroglia, which are the parts primarily and remissions, and its long-drawn-out duration, the similarity affected, and apparently the chronic inflammatory changes is striking. are secondary. The astonishing thing is the very sharp limit If due to a germ I am convinced it is a specific germ to each diseased spot, one indeed so marked that Strumpell as yet quite unknown. Whether the intermissions and supposed, but not on sufficient grounds, that the disease is remissions are due to the continual presence of the germ in largely of an endogenous nature due to a congenital abnor- the body with varied powers of immunity from time to time, mality of those parts affected, and that in this way a multiple or whether to fresh infection is not known. If due to an gliosis results. I do not think some interesting observations intrinsic poison the remissions would, of course, be due to made by my colleague, Dr. Williamson, in his work on the manufacture and absorption of fresh masses of poison. " Diseases of the Spinal Cord," have been sufficiently noticed. I am sorry to have to confess that in spite of minute He says:inquiries into the previous histories of large numbers of "The shape of the patches and their regular margins in cases of this disease I have so far entirely failed to elicit disseminated sclerosis are suggestive of the infiltration of the any evidence of any common factor, although my questions nerve structures with a fluid of destructive character, the have covered a large field. There is evidently another field conditions. of the determined margins byphysical patch being If a spinal cord which has been hardened in Muller’s fluid to explore, and I would strongly recommend to young members be touched on its external surface or on the cut surface of a of our profession that here is a subject of research well transverse section, with a minute drop of deeply coloured worthy of attention and in which the discoverer of the true fluid such as a strong solution of aniline blue-black, the fluid cause will gain a rich reward. diffuses itself into the cord substance, and a stained patch is OTHER DISEASES. formed with a fairly regular, curved, clean-cut margin, a and which of the Another common structures the various passes through margin very distressing affection which cord abruptly and indifferently, and thus resembles that of a needs urgent investigation as to its real cause is rheumatoid patch of disseminated sclerosis. This fact is suggestive of arthritis, for although I am willing for the present to admit the patches being caused by the infiltration of the nervous that it is due to some toxin, this is by no means proved. Nor system with a toxic fluid, their shape and margin being is it known if it is due to a germ toxin or to some intrinsic determined by physical conditions." poison arising from imperfect metabolism. In a footnote he adds : Epilepsy and migraine, two very common and disabling " Alcohol and several other chemical fluids have the power I have classed in the hereditary group ; but how affections, white out the substance of Schwann from the of dissolving we should be to know the real cause. glad of the cord fibres of and brain these in specimens kept nerve Two other diseases, fortunately not common, I find a fluids for long periods, whilst the axis-cylinders and other structures are left. Thus a microscopic appearance is difficulty in classing-namely, spleno-medullary leukæmia produced on section which somewhat resembles that of one and true facial neuralgia. The former seems allied to -

pallidum

the ’

709 which in many respects, especially in 1there had been an operation for the removal of a rifle bullet i the lung. In 51 of his cases a foreign body remained fatal results, resembles a germ infec-from i the chest, and Colonel Elliott does not think that this tion ; but in symptoms and course spleno-medullary and in i the gravity of the prognosis in any instance. lymphatic leukmmia are so different that one sometimes increased As regards the disposal of our 50 patients, 12 have been wonders why they have generally been described together, i to Canada or Australia or have been discharged as unless it is that both are due to the same cause, but one invalided a chronic one, just as permanently the other acute unfit. One was tuberculous. Two died (as a course, I very running may happen in some other germ diseases, as, for instance, 6already mentioned, after operation). Three were categorised :as I I C 3 " or "permanent base duty, 4 went to "light tuberculosis or glanders. and the remaining 29 were sent to full duty, "A3," duty," I have narrowed down diseases from the point of view ofor ( Comruand Depot,"where they would soon be considered This may appear surprisingly fit cause into ten groups only. f to return to their units. Thus out of the 50, 36-i.e., small and surprisingly simple. Allowing for that latitude*;72 per cent.-were fit for some military duty, and only 14 which is always necessary when looking at very many objectswere lost to the Army. The different ways of disposing of from a large standpoint, I do not think I have taken manytthe patients is due to the fact that some were imperial men, liberties in putting any particular disease into any particularwhile the rest were from overseas. I do not that the classification is pretend group, although There must now be an immense number of these cases back one strictly conforming to the logical laws of classification. at the Front and on other military duty, and yet how seldom But I think the grouping is a convenient one, and I trust that iis it that they are again invalided on account of disability on testing it will be found to stand criticism, and may be esulting from the late effects of the retained foreign bodies. helpful in enabling us to steer a true course to reach theDuring my work in the past year in Canadian hospitals in haven of real cause, and after reaching it to perform our nextI England, and again in such work in France for nearly two and highest duty, real prevention. years, I do not remember having come across such a case. and my colleague, Colonel F. G. Finley, tells me that his experience has been the same over a similar period. all soldiers who have been shot in the chest, and THE LATER HISTORY OF CASES OF n Nearly whom the missiles are still retained, complain of some GUNSHOT WOUNDS OF THE CHEST, ;ough and shortness of breath and of some pain in the chest, out I cannot say that they complain any more than do WITH RETAINED MISSILES. .hose in whom the missile has passed through and through. BY ROBERT DAWSON RUDOLF, M.D. EDIN., F.R.C.P., Further, in the former case most men have unfortunately )een told that the foreign body is still in the chest, and have COLONEL, C.A.M.C.; CONSULTING PHYSICIAN TO THE CANADIAN ven been shown the X ray plates, and the knowledge so FORCES IN ENGLAND. tcquired is bound to make them introspective and thus will THE question of what becomes of soldiers who have been etard their complete recovery. shot in the chest and in whom the missiles are still present The Question of Operation. is one of great importance, as it bears directly upon the The of the early removal of large pieces of, in all question treatment of such cases. Should such missiles be immeforeign material is not one that can be probability, septic diately removed or should they be left alone ? are the discussed now, but I note with entire approval that Colonel questions which are being much discussed at the present alliott thinks that such large pieces of shell and shrapnel time. In a general way it may be said that among the in the should be disposed of at once, as they asing lung French medical officers the tendency is frequently to attack such cases surgically, while amongst the British practitioners will almost certainly produce gross infection, with frequent evere haemorrhage, if left alone ; but with this exception it a more conservative policy is usually adopted. would seem well to be very chary about removing small The matter can only be settled when we have sufficient oreign bodies, especially rifle bullets and shrapnel balls. data to enable us to form an opinion as to what harm such ’hese do not seem to do any harm if left alone, and in no in must know do when left and also we bodies situ, foreign ray increase the gravity of the symptoms produced by other what is the immediate risk to life of active surgical interssociated conditions, such as hæmothorax, pneumothorax, ference. This war is, unfortunately, providing us with only nd actual lung lesions. too much material upon which to form such opinions, and in Colonel El’liott states that it would appear from recent the meantime, until great masses of statistics are avail’rench publications that the mortality is much higher in on to as record as cases be able, placed many possible may best wounds than was at first supposed, and that this high help in this direction. icrtality requires vigorous efforts on the part of the surgeons The Present Investigation. save life. "Also, in respect of casualties who survive For some months now I have been endeavouring, at the !lese wounds, evidence is brought forward to show that suggestion of Lieutenant-Colonel T. R. Elliott, to collect atained projectiles, and especially shell fragments, almost notes of patients in the Canadian hospitals in England, who lways cause trouble, either by the introduction of sepsis, have undoubtedly got foreign bodies in the chest, as shown r, if sterile, by the introduction of later pathological by X ray examinations, and, although the list is still a small hanges or symptoms that incapacitate the patient for service." Hence it has been urged by several surgeons that all shell one, I give it as an early contribution to the subject. A large number of cases have been seen in the hospitals who ’agments, other than those of small size, should be removed have not yet been finally disposed of, but these are not ithin the first 24 hours, with a cleansing of the wound included, as it is the final fate of such cases that we wish ack, suture of the lung, and evacuation of blood-clot from to ascertain. ie pleural cavity. With this rule there will probably not be In each of the cases in the list the X ray findings are tuch difference of opinion. But the same authors go on to given, and it will be seen that I include all cases in which the ivocate ’’ the removal from the thorax of all other retained foreign body lies deeper than the ribs, so that in some reign bodies at a much later date when the possibility of instances these are not in the lung at all, but it seemed wise optic complications has passed away." In my humble to include them in the series. pinion no such routine operation is called for. There are It will be observed that there were only two deaths in the list, cceptions. of course, as where such a foreign body is giving and it is interesting to note that these two patients had been se to active trouble. Thus, in Case 6 in our series the atient had a resection done for an empyema and a peroperated upon for the late removal of the retained foreign body. In one of them (No. 9) an abscess had formed round anent sinus remained, which eventually was found to lead the offending missile, so that in this case an operation was rectly to a piece of shrapnel which lay in the lung sururgently required, but in the other instance (No. 13) the !unded by fibrosis. This was removed and all the acute patient was apparently well, and it would probably have ’mptoms disappeared and the sinus closed, and the patient been wiser, as the sequel showed, if he had been left alone. as well on his way to recovery before he left for Canada. In a paper in THE LANCET of Sept. 8th last, by Colonel Even if it should occur that these foreign bodies do comElliott, there is a list of 170 cases of gunshot wounds of the only at a much later date produce distress, probably it ould then be less risky to remove them than to do so earlier chest, in which the after-history had been traced, and the only case that had a, fatal issue in. England was one in which erely in anticipation of such possible trouble.

lymphatic lenkaemia, frequently rapidly

its

"