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THE 
 
 PEDIG-EEE OF DISEASE 
 
 SIX LECTURES 
 
 ON 
 
 TEMPERAMENT, IDIOSYNCRASY AND DIATHESIS 
 
 DELIVERED EST THE THEATRE OF THE ROYAL COLLEGE 
 OF SURGEONS IN THE SESSION OF 1881 
 
 JONATHAN HUTOHINSON, F.R.S. 
 
 Late Professor of Surgery and Pathology in the College; Emeritus Professor of Surgery in the 
 London Hospital; President of the Ophthalmological Society, etc., etc. 
 
 NEW YOEK 
 WILLIAM WOOD AND COMPANY 
 
 56 & 58 Lafayette Place 
 
 ISgg 
 
lOo, /4c/^9- 
 
 
 r 
 
 The Pueushees 
 
 Book Composition and Electeotypino Co. 
 
 157 AND 159 William Street 
 
 New York 
 
Uo tbe /IDemorp 
 
 OF 
 
 CHARLES DARWIN 
 
 THESE LECTURES 
 
 ARE 
 
 REVERENTLY INSCRIBED. 
 
PREFATORY NOTE. 
 
 With a few emendations I have reprinted these Lec- 
 tures just as they were deHvered in June, 1881, and as 
 they appeared at the time in one of the medical journals. 
 I am well aware of their many imperfections, but am 
 hopeful that they may be found to point to work in the 
 right direction. It was, indeed, the commendation 
 which this method of dealing with some of the problems 
 of disease received from Sir James Paget, in his Brad- 
 shaw Lecture of last year, which induced me to deter- 
 mine on their present publication. 
 
The Pedigree of Disease. 
 
 LECTURE I. 
 
 Me. Peesidekt and Gentlemen, — I fear I do not much mistake 
 in the belief that the subjects which I have ventured to take for my 
 present course of lectures are by no means high in professional favor. 
 Our forefathers, who knew far less about the details of pathology than 
 we do, attached far more importance to such matters as temperament 
 and diathesis. They were accustomed to prescribe for a man's tem- 
 perament; we think only of his disease, and turn aside with weariness 
 from classifications of diathesis in which the physicians of an older day 
 delighted. Although to a large extent this change of sentiment has 
 been the result of advance in knowledge, yet I think it might easily be 
 shown that it has gone too far, and that we now neglect unwisely the 
 study of those differences between man and man of which, for the most 
 part, physiology takes no cognizance, but which may yet prove of much 
 importance in modifying the processes of disease. It is to this study 
 that I now invite your attention. I have been attracted to it in part by 
 its own intrinsic interest, and in part by the circumstance that it has 
 seemed to be, in some sense, supplementary to the lectures which on 
 former occasions I have had the honor to deliver from this chair. In 
 my first course (three years ago) I investigated the present state of 
 knowledge as to the influence of the nervous system in the production 
 of disease. In the second we examined those remarkable and widely- 
 spread forms of diathesis known respectively as Gout, Eheumatism, and 
 Leprosy. When on these subjects I tried to show that rheumatism is a 
 modification of the catarrhal diathesis, mainly nervous in its origin, in 
 
 which the stress of the refiex disturbance falls upon the tissues of the 
 1 
 
2 THE PEDIGREE OF DISEASE. 
 
 joints. I traced a close parallel between gout and leprosy, alleging that 
 both are food-diatheses, being distinctly and definitely caused by certain 
 peculiar articles of diet. Eespecting both we had to remark upon the 
 facts, that having been thus acquired by food, they became capable of 
 transmission from parent to child, and that gout, at any rate, was prone 
 to receive important modifications in such inheritance. In my third 
 course, delivered last summer, I was led by a not unnatural sequence 
 to take as my topic the laws of pathological inheritance in general, and 
 to deal with them in relation to such maladies as syphilis, gout, leprosy, 
 catarrh, and certain specialized defects, such as deaf-mutism, color- 
 blindness, and haemophilia. In each one of these courses I have been 
 obliged very frequently to use the term "diathesis," and to justify its 
 use against what I have all along recognized as a widespread and to some 
 extent well-grounded distrust of the vagueness of the knowledge, or, 
 shall I say, of the mere ignorance which its employment not unfre- 
 quently denotes. It has thus occurred to me that I could not take for 
 the present course a subject more suitable than the one which I have 
 announced. It will enable me to recapitulate, with amplification, some 
 of the topics to which on former occasions I adverted to briefly, to ap- 
 proach them from a different point of view, and, I trust, to place some 
 of them in a clearer light. In doing this it will be my duty to avoid 
 repetition, but if I should now and then seem to any of my audience 
 who have honored me on former occasions to be attempting to enforce 
 that concerning which I may be thought to have previously said enough, 
 I must beg their indulgence. I must also offer some preliminary 
 apology for the incompleteness and fragementary character of my lec- 
 tures. It will be impossible to pass even in the most cursory manner 
 over the whole of the ground indicated, and I shall therefore prefer to 
 dwell with some considerable detail upon certain portions of my subject 
 with which I am personally familiar, and which also appear to have 
 special value as illustrating general laws. 
 
 It is needful, in beginning, to define our terms, and in doing this I 
 shall keep as closely as possible to customary usage. We may perhaps 
 define the term temperament as applicable to the sum of the physical 
 peculiarities of an individual, exclusive of all definite tendencies to dis- 
 ease. Different temperaments are to be assumed to be likely to give 
 
TEMPERAMENT AND DIATHESIS. 3 
 
 some degree of peculiarity to morbid processes when such, have been 
 induced by other causes; but they do not in themselves involve any 
 special proclivity. When most strongly marked, temperament is still 
 consistent with the prolonged enjoyment of perfect health. If there be 
 distinct proclivity, we must then use a stronger term, and speak of 
 diathesis; and I would define a diathesis to be any bodily condition, 
 however induced, in virtue of which the individual is, through a long 
 period, or usually through the whole life, prone to suffer from some 
 peculiar type of disease. Some diatheses are inherited, others are ac- 
 quired. Of some, the effects are permanent or constant; of others, they 
 are transitory, or recurrent after intervals of health. The term should, 
 however, never be applied to any condition of health which is expected 
 to pass away and leave no trace, for the idea of persistency, in some 
 sense, is always implied. On the other, hand, we do not confuse dia- 
 thesis with dyscrasia, for whilst the latter definitely implies bad health, 
 the former only denotes proclivity, and may be used when its subject 
 seems perfectly well. Thus, to distinguish between temperament and 
 diathesis, we may say that the former is a matter of physiology and the 
 latter of disease, and that the former term is applicable only to pecu- 
 liarities which are a part of the original organization of the individual, 
 whilst the latter may be acquired as well as inherited. Thus, inherited 
 diathesis is more often than not entirely latent at the time of birth, and 
 is susceptible of aggravation, or, in some cases, of cure, in after-life. 
 Such alternations are not possible in the constitutional peculiarities 
 which we name as temperament. 
 
 Concerning the term Idiosyncrasy, I will not say more in the way of 
 definition than that it is applicable to any definite peculiarity of or- 
 ganization of which the consequences may occur unexpectedly and 
 otherwise inexplicably. It does not, like diathesis, imply any special 
 proneness to disease, only that under certain well-known circumstances 
 results which are peculiar to the individual will certainly occur. Al- 
 though, as I shall have occasion to observe, it is quite possible that the 
 idiosyncrasies may in many instances have sprung from the diatheses, 
 yet they have become in long hereditary transmissions questions rather 
 of organization than of disease. Their existence may, however, be re- 
 vealed for the first time at any period of life, and nothing is more com- 
 
4 THE PEDIGREE OF DISEASE. 
 
 mon than that an idiosyncrasy should pass into absolute abeyance, to 
 wait until, after it may be a very prolonged period, its proximate ex- 
 citing cause may again make it conspicuous. Just as observers of man- 
 kind have from time to time strained their faculties in the endeavor to 
 find in the external lineaments of a man some clue to his mental power 
 and moral habits, so have physicians sought to find in parallel indica- 
 tions the means of predicting his tendencies in reference to disease. As 
 yet I fear we must say that the labors of the physiognomist and those 
 of the student of temperament have been alike disappointing. Who- 
 ever will set himself the task of attempting to classify a given number 
 of individuals according to their temperaments will, I think, soon find 
 h'mself baffled. He will discover that he is mistaking for criteria of 
 temperament conditions which are simply indicative of youth or age, of 
 health or disease, or the effects of past anxiety or trouble, or of com- 
 parative immunity from them. Just as the physiognomist ought care- 
 fully to exclude from his estimate of the original and inborn character 
 of a man those traits of expression which have come to him through 
 the wear and tear of life, and keep closely to the original features, so 
 should the student of temperament scrupulously reject all that has been 
 superadded, and which is in a sense accidental. Temperament, as I 
 have endeavored to define it, concerns the original inherited organiza- 
 tion of the individual, and does not include anything which is the result 
 of the influences to which his life has exposed him. That which has 
 accrued to him during life goes to produce or aggravate diathesis, but 
 can do nothing in modification of temperament. Dr. Laycock has well 
 spoken of the temperaments as being " fundamental modes of vital ac- 
 tivity peculiar to individuals." To some such conception as this we 
 must keep if we would use the word with any precision. Yet a very 
 slight familiarity with the subject will easily show us how difficult it is 
 so to restrict its use, and especially is this the case when dealing with 
 adult and senile periods of life. The very names of the temperaments 
 in many instances denote the record of the results of long-existing dis- 
 ease rather than of individual peculiarities as regards vital activity. In- 
 deed, it may be questioned whether in a large majority of cases there 
 do. really exist in persons as yet in perfect health any peculiarities by 
 which we can predicate or discriminate the " fundamental mode of vital 
 
CRITERIA OF TEMPERAMENT. ;) 
 
 activity." Disease, when it occurs, will reveal it to us, and upon this 
 point I shall have much to say in subsequent lectures. But I fear that 
 so long as perfect health exists the data are exceedingly few and un 
 trustworthy. When, for instance, we recognize a melancholic tempera- 
 ment, do we not usually take note of something which is the result of 
 disease which has been experienced in the past, rather than of a pecu- 
 liarity possessed by the individual whilst in health? The features 
 which go to make up the sanguine temperament, are they not in part, 
 and in large part, often those indicative of sound health in the digestive 
 functions and blood-making organs, and such as might possibly be de- 
 stroyed by a few years ' illness ? If we seek for something more funda- 
 mental, shall we not be obliged to confess that we have but little to 
 guide us in a classification excepting the conditions which go to make 
 up what we mean by complexion ? In complexion we include the color 
 of the hair and eyes, the state of the skin as regards thickness, thinness, 
 or transparency, and the various degrees of freedom of distribution of 
 blood in the capillaries of the face. It is easy to apply with tolerable 
 accuracy such words as blonde, fair, dark, brunette, sallow, pale, florid, 
 clear, muddy, and the like, and these and many others are epithets ap- 
 plicable to the complexion. Temperament, however, although to a 
 large extent confessedly indicated by complexion, is generally held to in- 
 clude something more. If it did not I fear we should find it but a 
 sorry basis upon which to build a knowledge of the vital peculiarities of 
 the individual. Yet again, I ask, what have we to which we can make 
 appeal ? We may examine a man's features, note the size of his bones, 
 the shape of his jaws, the brilliancy of his eye, the coarseness or fineness 
 of his hair, his stature, his muscularity, his abundance or otherwise of 
 cellular tissue and fat; but in observing all these things we shall be re- 
 minded that some of them are simply peculiarities of family or of race, 
 and have little or nothing to do with health, whilst others are condi- 
 tions which may vary much at different periods during the same life. 
 Above all, if I mistake not, we shall find it quite impossible to combine 
 with well-known and indelible types of complexion any correlative 
 peculiarities as regards the points which I have just enumerated. We 
 shall find fair persons who have coarse skins, and others of the same 
 tint of hair and eye who have transparent skins. We shall find dark 
 
G THE PEDIGREE OF DISEASE. 
 
 people who are florid, and others who are pale, and we shall have to 
 note that the tendency to fatten varies very much at different periods 
 of life, and that it often depends quite as much upon diet as upon tem- 
 perament. I come then back to my point, and assert that whoever will 
 set himself to classify by temperament a dozen healthy individuals 
 whom he may chance to meet on a steamboat, in a law court, or at a 
 dinner party, will find that he has scarcely any data excepting those of 
 complexion. He will find, moreover, unless I am much mistaken, that 
 if he attempts to go beyond mere complexion, there are not more than 
 two or three in the dozen whom he can with any degree of confidence 
 assign to special temperaments. As to complexion itself, the further he 
 goes the more he will have to confess that, putting various conditions of 
 sanguification aside as being in many persons dependent upon varying 
 states of health, he can after all classify the complexions themselves 
 only in reference to pigmentation. The varying degrees of dark, fair, 
 or red constitiite almost the sole individual peculiarities of the complex- 
 ion which are not altered by disease or diet. 
 
 We come then to the question — Are congenital peculiarities as regards 
 pigmentation in any degree trustworthy as indicative of vital peculiari- 
 ties in the individual possessing them ? We will ask the question first 
 as regards individual races, and next as regards different individuals of 
 the same race. That pigmentation as we now see it in the various races 
 of man is an inherited quality and so definitely transmissible that it 
 constitutes one of the bases of race distinction, may easily be admitted, 
 whilst at the same time we must also grant that it is in itself a result of 
 climate. Those who live in the tropics become dark, without question, 
 as the result of the direct influence of the sun; whilst those who live in 
 more temperate climates lose their pigment, or retain it only in certain 
 special structures, as the hair, the irides, and the choroid. If apparent 
 exceptions to this general law occur, they are to be met with probably 
 as the consequences of human interference in modifying the conditions. 
 Thus, the habit of wearing clothes prevents the development of any ap- 
 proach to blackness of skin in white races who may have lived through 
 many generations in the tropics. The blackest skins always belong to 
 those who have joined the two conditions of nakedness and a tropical 
 sun. Thus, then, to begin at the beginning, may we not believe that 
 
TEMPERAMENT AND EACE. 7 
 
 varying states of pigmentation of the integument denote rather exposure 
 to climatic influences than peculiarities of development? Nor is there, 
 so far as I know, much reason for believing that variations in this re- 
 spect imply any material difEerences in health tendencies. Such pecu- 
 liarities as we recognize in different races — the immunity of the negro 
 from yellow fever, his liahility to elephantiasis and to tetanus — may 
 easily have nothing whatever to do with his pigmentation per se, and 
 he matters simply of race. This view, I think, derives considerable 
 support from the facts which I shall mention directly as regards the 
 peculiarities of dark or fair complexions in members of the same race 
 and amongst the lower animals. 
 
 If I have seemed to insist too much upon mere differences in com-' 
 plexion as being those to which almost all observers unconsciously trust 
 in their endeavors to discriminate the temperaments in persons in good 
 health, let me ask those who doubt it, to imagine themselves set to 
 classify a group of negroes. It may be that the sameness in negroes is 
 not nearly so great as it may appear to us, who are accustomed to deal 
 with persons of very various types of complexion, and that those who 
 have lived amongst them might be able to effect some sort of classifica- 
 tion. "We know that in a flock of sheep, which, to the untrained ob- 
 server, all seem exactly alike, the shepherd can usually find distinctive 
 individual differences. Admitting this, I still doubt, however, whether 
 it would be practicable to apply to a race, in which all the individuals 
 are highly pigmented, many of the facts which have hitherto been held 
 to discriminate temperaments. We can recognize easily individual 
 peculiarities — we can recognize also the peculiarities of race — but if the 
 race be pure and the color uniform, we should have remarkably little 
 to guide us. This statement leads obviously to the suggestion that I 
 am perhaps involving ihyself in a fallacy, and that it may be the fact 
 that what have been called the temperaments are observed almost solely 
 under conditions in which the race is much mixed. It is certainly true 
 that doctrines on this subject have been developed only under condi- 
 tions of long-established civilization, and where the population repre- 
 sented those who derived their blood from various sources. Dr. Lay- 
 cock has given a valuable hint in this direction, and has remarked that 
 we greatly need a British ethnology founded on well-defined and dis- 
 
8 THE PEDIGREE OF DISEASE. 
 
 tinct characteristics. Thus, it might he, perhaps, much nearer the 
 truth if we were to classify those who make up our own population not 
 according to complexion, as fair, red, black, etc., nor by reference to 
 certain more or less hypothetical vital tendencies, as lymphatic, bilious, 
 sanguine; phlegmatic, and the like, but rather as Celtic, Scandinavian, 
 Eoman, or English. It is quite true that we should find a compara- 
 tively small number who could be definitely placed under any one of 
 these heads, and that the large majority present features of racial mix- 
 ture which would utterly defy classification. But the same difficulty has 
 to be met by those who prefer to make groups under the head of tem- 
 perament. A large majority belong to no one in particular, and partake 
 of the characteristics of several at once. Modern historical authorities 
 are desirous, I am aware, to have it believed that the English popula- 
 tion is not mixed to anything like the extent which it was formerly the 
 custom to suppose. They delight to claim us as English pure and 
 simple, and to mean by the term direct pure-blooded descendants of the 
 Angles and the Saxons. They appeal to the fact of what is called the 
 Saxon invasion — I must ask pardon, the English invasion — as to the 
 entire extermination of the Eomanized British population, from the 
 land of which we are now in possession. They appeal also, and I must 
 admit with more cogency, to the almost absolute substitution of a Ger- 
 man language for the British tongue. There are, however, I think, 
 good reasons why the student of race and believers in its permanency 
 should hesitate to accept fully this new creed. "We have amongst us far 
 too many who possess not only typical Eoman noses, but all the pecu- 
 liarities of character which usually accompany the Eoman cast of face. 
 It is more difficult to feel certain as to the persistency of the British or 
 Celtic element, since we know mach less well what its peculiarities were. 
 "Whatever the evidence may be as to extermination by the invaders of 
 the males who opposed them, nothing is less probable than that the 
 women were included in the massacre. An army of invading and colo- 
 nizing males would be certain to preserve sufficiently numerous repre- 
 sentatives of the conquered race to effect a very material modification of 
 the future stock. "Whilst on this subject it is also, I think, fair to 
 suggest that the present frequency of the Eoman face in England, may 
 not improbably be due in part to prepotency in that remarkable race. 
 
PHYSIOGNOMICAL DIAGNOSIS. 9 
 
 Although I would by no means propose classification by race as likely 
 to be of any great value in reference to clinical research, yet I do seri- 
 ously think that it would be more practicable, and come nearer to the 
 truth, than the classification bj temperament. A glance at what has 
 been attempted in the latter direction will^ I think, convince us that 
 even those who manifested the greatest ingenuity, and possessed the 
 soundest and most extensive knowledge concerning health and disease, 
 have been obliged, when describing the temperaments, to avail them- 
 selves of many criteria which are really the phenomena of disease. 
 Chief among those to whom I allude stands one to whom I have myself 
 been greatly indebted — my first teacher of medicine, the late Professor 
 Laycock. With a power of insight which amounted almost to genius. 
 Dr. Laycock had applied his mind to the study of the physiognomical 
 diagnosis of disease, and by long practice in observations in this direc- 
 tion, he was enabled sometimes to give opinions which astonished those 
 who were accustomed to more plodding methods of investigation. In a 
 series of lectures delivered, in 1861, and published in the following 
 year in the ' Medical Times and Gazette,' he embodied the results of 
 his experience. He believed that his rules of diagnosis were to a large 
 extent based upon peculiarities of temperament, and he naturally gave 
 great attention to the correct classification of these so-called fundamental 
 states. For myself, I cannot doubt that the knowledge which he found 
 so useful was based not so much on the discrimination of temperaments 
 as on the recognition of diathesis. I couM illustrate this statement by 
 innumerable quotations from the lectures to which I have referred, in 
 which features distinctly the result of bygone disease are mentioned, as if 
 they formed part of the original organization. Our time will not permit 
 that I should enter into any detail upon this point; but as Dr. Laycock's 
 is, so far as I know, the last and certainly by far the best of all attempts 
 to classify temperaments, I think it may be convenient that we should 
 devote a few minutes to its consideration. He endeavored, as he tells 
 us, to avoid the use of new terms, and to apply the old ones with defi- 
 nite meaning, as significant of predominant modes of vital activity. He 
 recognized, six divisions — first, persons nervously active from predomi- 
 nant innervation; secondly, those with predominant sanguification and 
 activity of the vascular and muscular systems; thirdly, those in whom 
 
10 THE PEDIGREE OF DISEASE. 
 
 both innervation and muscular activity are predominant, and this ex- 
 isting with also predominant carbon deposit or excretion — the fibrous or 
 bilious temperament; fourthly, when the muscular system is well devel- 
 oped, but neither sanguification nor inner-vation predominant, and there 
 is a decided tendency to the deposit of fat — the phlegmatic temperament ; 
 fifthly, those who are defective as regards innervation, sanguification, and 
 muscular and vascular activity — the lymphatic temperament; and, sixthly, 
 those in whom, with defective innervation, sanguification, and vascular 
 activity, there is a combined tendency to carbon deposit— Wie melancholic 
 temperament. Here we have, with a little expansion, the original four 
 temperaments-i— sanguine, nervous, bilious, and lymphatic. Let us ask 
 if they are real, and if the features by which they are to be recognized 
 are such as are likely to be permanent in the individual, and unmodi- 
 fied by alterations in his state of health. In the first place, I would 
 suggest that the melancholic temperament and the bilious temperament 
 are, after all, only different degrees of the same thing, and that, as life 
 advances, the one is very apt to pass into the other; and, further, that 
 the distinguishing feature in both is one which concerns disease rather 
 than temperament, and which might be more conveniently known as 
 the hepatic diathesis. It is the proneness to disordered function on the 
 part of the liver, its ready and frequent occurrence, which for the most 
 part stamps peculiarity on both these so-called temperaments. Further, 
 it is much to be doubted whether this facility of hepatic disturbance 
 would be found in association exclusively, or even generally, with any 
 particular cast of the features, or, recognizable peculiarities in the gen- 
 eral frame. Certainly it is not, by any means, the exclusive possession 
 of dark complexioned persons, nor, perhaps, does it more abound 
 araongst dark complexioned nations — the Italians, to wit^than amongst 
 others. It is a matter of race, of family, and of climate. It may be 
 diminished or aggravated by various conditions of life, and it is usually 
 recognizable only after certain definite phenomena of disease have been 
 already experienced. As regards its being worth while to distinguish 
 any condition as the nervous temperament because innervation is pre- 
 dominant — or, in other words, the central cerebro-spinal system is 
 largely developed — much doubt may, I think, reasonably be felt. A 
 high development of the nervous system is again a peculiarity of race 
 
CLASSIFICATION OF TEMPERAMENTS. 11 
 
 and of family rather than of anything with which we as medical ob- 
 servers have to do. The conditions in which the nervous system i& 
 subject to disease are rather those of instability than of simple prepon- 
 derance. The phlegmatic temperament gets its peculiarity from the 
 tendency to fatten; but, as I have already observed, this tendency is shown 
 in different periods of life, and is much modified by habits of diet and 
 social surroundings. So of the lymphatic temperament, in which all 
 functions are sluggish, and a general failure of what we may call 
 "tone" is the conspicuous peculiarity. I would submit that this con- 
 dition is not unfrequently induced by disease occurring during the life- 
 time of the individual, and not by anything which caji possibly be 
 denoted by peculiarities in the general formation. Dr. Laycock's classi- 
 iication of the temperaments is also, in common with the older ones, 
 open to the criticism tliat, inasmuch as it takes little or no account of 
 the more conspicuous differences in complexion, it afEords us but few 
 facts by which to recognize them. When a man is florid and muscular, 
 it is not diflQcult to say that he is of the sanguine temperament; but 
 these conditions are, perhaps, indicative rather of good digestion and 
 sound health than of intrinsic peculiarities. The appetite may fail, or the 
 health give way, and some of the signs supposed to denote temperament 
 may easily vanish. Would it not be more convenient to speak of a man 
 as being simply, for the time being, florid and muscular, than by the 
 use of such a term as "sanguine temperament" to imply permanency 
 in qualities which may easily prove to be otherwise ? If we cannot iden- 
 tify the sanguine temperament by other characters, probably it would. 
 The peculiarities which denote family and race must be viewed with the 
 utmost caution, as well by the physiognomist in reference to character 
 as by the physician in respect to tendencies to disease. They are 
 usually of no use, and they may easily mislead. It is only indirectly 
 that they may become valuable — that is, when the special proclivities 
 of the race or family in question are known beforehand. A thick upper 
 hp, when it occurs in a mulatto, denotes descent only, and not scrofula. 
 The peculiarities of the Hebrew features reveal only the race, and are 
 of use to the physician only so far as he may be acquainted with the 
 facts as to the special tendencies to disease in that race. 
 
 I have been speaking thus far on the subject of temperament con- 
 
12 THE PEDIGREE OF DISEASE. 
 
 sidered as the aggregate of a man's physical personality, and have felt 
 obliged to return the verdict that its study in this form is but little use- 
 ful for our purposes as surgeons. It will I think, however, be well to 
 say a few additional words respecting some of the individual peculiarities 
 which have been held to make up temperament. 
 
 We will begin with the subject of complexion. The color of the hair, 
 skin, and eyes may be easily observed, and although the English popu- 
 lation, in a majority of cases, is a very mixed one, yet abundant oppor- 
 tunities occur of taking note of very definite types. Observations are 
 yet wanting which would justify us in believing that any special tenden- 
 cies to disease are implied by differences in the pigmentation of the hair 
 and skin. It is, however, a subject of much interest for further re- 
 search, and thinking that it might possibly be useful to others, I have 
 placed before you a brief list of the more definite complexions which I 
 prepared for my own guidance many years ago when investigating the 
 subject of scrofula. In endeavoring to determine whether any given 
 disease occurs in special connection with any one complexion, we are 
 met at once with the difficulty that we do not know what the relative 
 proportions of the several complexions are in the English population. 
 Nor would it be sufficiently accurate for the purposes of any local ob- 
 server to know the proportions of fair, rufous, dark, etc., in the British 
 population generally, since these probably vary very considerably in 
 different districts, and even in different towns. I cannot but think 
 that careful statistics upon this head — collected in small towns and vil- 
 lages where it might be practicable to count the whole, and made, too, 
 by trained observers — would prove of considerable value in more than 
 one direction. It is in external diseases chiefly, such as lupus, psoriasis, 
 and the like, of which the diagnosis is easy, that we should find the best 
 opportunities for testing prevalence in relation to complexion. At one 
 time I had formed a strong opinion that lupus, to take a marked ex- 
 ample, was met with much more frequently in, those of dark complex- 
 ions, persons of dark brown hair, brown eyes, and a bluish sclerotic 
 through which the pigment of the choroid is somewhat seen. I have 
 collected a good deal of statistical evidence on this point, but it remains 
 useless so long as we are ignorant of the relative proportions of the com- 
 plexions amongst those from whom the cases came. It is probably the 
 
TEMPERAMENT AND COMPLEXION. "13 
 
 fact that both professional and lay observations concur in supporting 
 the creed, that there are differences — mental, moral, and physical — be- 
 tween the fair and the dark; yet it would be exceedingly difficult to say 
 anything definite as to what these differences are. I was myself taught 
 by a careful practical observer, the late Mr. Wormald, that' all persons 
 of the dark complexion would bear mercurial treatment well, and would 
 require larger doses than those who are fair. I have been accustomed 
 ever since to act on this belief, and I think it is certainly well founded, 
 although there are many exceptions to it. I have even gone farther 
 than my teacher and come to believe that a great many persons of the 
 dark complexion not only bear mercury well, but enjoy better health 
 whilst taking it, and are not unfrequently much and permanently bene- 
 fited by a long course. It is but fair that I should admit, however, 
 that one of the most remarkable examples of tolerance of this drug 
 which I have ever met with, occurred in a patient of very fair complex- 
 ion. Further, I have acquired, possibly on insufiicient data, a sort of 
 practical belief to the effect that dark-complexioned persons do not bear 
 direct tonics well, that the need of purgatives is greater in them, and 
 that they are often not helped by sea-air. Beyond these items of un- 
 certain creed I cannot go, and even granting that they are sound, it 
 remains still an open question whether the mere difference in pigmenta- 
 tion is, fer se, their explanation. It may be after all that this difference 
 in complexion is, as we see it in English society, mainly useful as a clue 
 to descent, to family, and remotely to race. Many facts concur to 
 imply this. When an albino chances to occur in a dark family (as is 
 usual), he does not, I believe, show any special liabilities to disease, or 
 differ in any way from his brothers and sisters, excepting in the local 
 inconvenience as regards eyes and skin. White horses, white cattle, 
 white rabbits, and white poultry are usually not possessed of any other 
 correlative peculiarities. There is a prejudice, and probably it is 
 nothing better, that they are slightly more delicate than colored ani- 
 mals. The breed of pigs in the South of England is usually black, 
 whilst in the northern counties white-skinned pigs are universally pre- 
 ferred. Such a fact is conclusive in proof that mere difference in pig- 
 mentation of the skin makes no material difference as to health or 
 feeding capabilities. In the different breeds of sheep we have frequent 
 
14 THE PEDIGEEE OF DISEASE. 
 
 illustrations of the power of race and family in giving peculiarity as 
 regards the tolerance of climate and proclivity to some diseases. But 
 the occurrence of a pigmented animal in any given breed does not, as 
 far as I am aware, entail any difference as regards health. The only 
 observation with which I am acquainted which contravenes this state- 
 ment is one quoted by Mr. Darwin, to the effect that black sheep can 
 eat with impunity a certain species of IIy2Jericum, which is poisonous to 
 white ones. This observation is so peculiar and so isolated that it must 
 be held to require further confirmation. Possibly, the strongest in- 
 stance in illustration of the unimportance of difference in general pig- 
 mentation occurs in the case of the common ferret. These animals 
 breed albinos very readily, and probably three fourths of those at present 
 in use in England have red eyes and white hair, the remaining quarter 
 being of a dark brown color. So far as I know, the one is just as hardy 
 as the other, and they are fed and treated in every way alike. Thus, 
 then, I think we may believe that in the English climate the abundance 
 or comparative absence of pigment in the tissues does not, 2jer se, make 
 any appreciable -difference in the vital endowments of the individual. 
 I am far from wishing to imply in saying this that the study of the 
 complexions, as regards pigment, is useless for clinical purposes. Its 
 uses have, however, for the most part, yet to be discovered, and it is 
 desirable to note, in passing, that although we 'name the complexions 
 chiefly in reference to pigmentation, something more than simply abun- 
 dance or deficiency is to be recognized in them. Thus, the rufous 
 complexion is due not merely to -deficiency, but to peculiarity in quality, 
 and is probably usually the result of the mixture of dissimilars. It is 
 very likely that a careful observation of a larger number of rufous 
 persons would confirm the popular belief that they do display peculiari- 
 ties, not only in temper and general character, but to a certain extent 
 as regards proclivity to disease. Again, the occurrence of great differ- 
 ences in color between the eyes and the hair, the eyes being much 
 lighter than the hair — as, for instance, black hair with blue eyes — is 
 probably an indication of delicacy. This, at any rate, is the general 
 belief. 
 
 Next in importance to the differences in pigmentation we have certain 
 other conditions which are usually included in what is meant by com- 
 
THE ELEMENTS OF C03IPLEXI0N. 15 
 
 plexion, such as the thickness or thinness of skin, its transparency, the 
 development of its glandular system, and the state of its appendages. 
 I dare not venture to say more respecting most of these than that they 
 are well worthy of further observation. We have exceedingly little 
 definite information regarding the clinical value of any of them. We 
 know that thick, coarse skins are more liable to be attacked by acne 
 than are those which are thinner; or, rather, perhaps I ought to say 
 that acne assumes difEerent forms in relation to the original endowments 
 of the skin which it attacks. In those of coarse skins comedones, pap- 
 ules, and pustules easily form, or we may even have a condition of 
 tuberous hypertrophy, whilst in those of thin, transparent skills, if the 
 causes of acne come into operation, an erythematous condition will be 
 produced, and the term rosacea become applicable. We believe — I 
 scarcely dare say that we know — that in children in whom the hairs 
 are thick and coarse the ringworm fungus finds an uncongenial home. 
 It might be possible to mention a few other detached observations as to 
 certain peculiarities in the skin and its appendages, not themselves due 
 to disease, which may guide us in estimating the future liabilities of 
 the individual. As a matter of general observation it may be asserted 
 that all marked deviations from the normal type should be held in some 
 degree of suspicion. Thus, if the hair is markedly coarse, or unusually 
 fine, if the skin be very thick or very transparent, we are perhaps justi- 
 fied in suspecting that there may be in other tissues similar departures 
 from the average constitution, some of which may prove inconsistent 
 with the preservation of perfect health. For the present, however, it 
 is speculation only. Of accurate observations we have none. The 
 teeth and the nails may be suitably mentioned together as structures 
 in which we very frequently observe with great interest and profit the 
 indelible consequences of past disease. These, however, belong to the 
 subject of diathesis, and do not concern us now. As regards peculiari- 
 ties of these structures occurring quite independently of previous dis- 
 ease, our knowledge is much in the same state as on the subject to 
 which I have just referred. Peculiarities in the form of the teeth are 
 often matters of family descent, and teach us nothing as regards their 
 possessor's liabilities. It is probable, however, that all peculiarities as 
 regards color and texture of teeth are of value, in proportion as they 
 
16 THE PEDIGREE OF DISEASE. 
 
 depart from the normal standard, as indicative of defective tissue forma- 
 tion in general. Dr. Laycock, in the interesting lectures to which I 
 have alluded, has examined at much length the various conditions of 
 the Ear as indicative of temperament and diathesis. He believed that 
 the form of the ear was of great value as a clue to the original develop- 
 ment of the brain, and that the state of its nutrition, blood supply, 
 etc., might help us to estimate corresponding conditions within the 
 cranium. His conclusions in the main are probably correct, but we 
 may doubt whether he did not push matters too far in assigning a 
 special state of ear to such conditions as general paralysis, and in con- 
 sidering in reference to this disease that the congenital adhesion of the 
 lobule to the cheek had some degree of significance. His observations 
 had led him greatly to prefer ears which had free lobules, and these, 
 too, of considerable size, which had all their different parts well marked, 
 and which were moderately fleshy, not thin and cartilaginous. , As re- 
 gards the matter of the lobule, it may be plausibly suggested that its 
 adhesion or otherwise indicates only family descent, and implies nothing 
 as to temperament, and the same to some extent is probably true as 
 regards the state of the helix and other parts. Making allowance, 
 however, for sources of fallacy in these directions, I think there can be 
 no doubt that the different states of the ear, as well congenital as ac- 
 quired, have been unduly neglected both by the physiognomist and the 
 physician. The ear affords excellent facilities for observation as to the 
 general state of nutrition and circulation, and the degree of perfection 
 in its form is a tolerably safe guide as to the descent of the individual 
 from a sound and well-bred stock. That it furnishes a clue to the 
 state of circulation in the brain better than does the color of the cheeks 
 and nose, or anything like as good as that afforded by the brightness of 
 the eyes, may be doubted, and before we make inferences on this point, 
 we must remember that the ears, as well as the nose, are remarkably 
 exposed to the influence of external temperature. 
 
 I have said so much in disparagement as well of the general as of the 
 special signs which have been held to indicate temperament, that I fear 
 it may be suspected that I almost doubt the reality of temperament in 
 itself. If I have given that impression let me hasten at once to remove 
 it. There can be no question whatever as to the reality of the differ- 
 
IMPORTANCE OF TEMPERAMENT. 17 
 
 ence between individuals, nor any doubt as to the importance of the 
 recognition of those differences by the medical practitioner. By far the 
 commonest error of the prescriber, and one which most interferes with 
 his success, is the easy-going habit of regarding all persons as alike, and 
 recognizing differences only in their diseases; or, to put it in other lan- 
 guage, of ignoring the predisposing causes, and taking account only of 
 immediate ones. The farmer who would succeed in his pursuits must 
 not content himself with making sure that he has sown good seed, and 
 according to the most approved methods. He must go further back to 
 take knowledge of the nature of the soil with which he has to deal, of 
 the cirops which it has previously borne, and of the manures which have 
 been used. It is much the same with us in the diagnosis and treatment 
 of disease. In addition to the primary or exciting cause, which is of 
 paramount importance, we have various others which may perhaps be 
 conveniently classed together under the term contributory, since they 
 contribute to control and modify final results. Amongst these tempera- 
 ment — the original vital endowment of the individual— is unquestiona- 
 bly a real force, and one which we would most gladly recognize and 
 estimate if we could. The scepticism which I have been expressing 
 applies not to the reality of the thing, but to Qur ability to discriminate 
 it. I shall have to speak in my next lecture on the subject of idiosyn- 
 crasy, and one of the facts which I think will come before us in the 
 clearest possible light is, that we possess no means whatever of recogniz- 
 ing by external configuration the subjects of these remarkable devia- 
 tions from the normal state. Who shall discover beforehand, the sub- 
 ject of hay asthma or the man in whom the iodide of potassium will act 
 like a poison ? When I come to the subject of diathesis we shall be on 
 wholly different and far firmer ground. Defining diathesis as a per- 
 sisting morbid procUvity we shall be able to show that in a great many 
 instances, either by the aspect of the individual, or the history of the 
 / case, a clear and definite opinion can be arrived at. The differences 
 which have been held to constitute temperament have had their remote 
 origin in two sources of influence; first, the hereditary transmission of 
 the peculiarities incident to race and family, which, for the most part, 
 entail no morbid proclivity whatever; and, secondly, to some one or 
 more of the various common causes of disease acting, perhaps, through 
 
18 THE PEDIGKEE OF DISEASE. 
 
 many generations. Thus, I cannot but think that what has been called 
 temperament divides itself naturally into these two parts, race and dia- 
 thesis. There is therefore but little advantage in retaining the word, 
 more especially when we have regard to the inextricable complexity of 
 the subject. As regards diathesis, the conditions are very different. 
 We can study the results of different causes in detail and with much 
 precision; we can express our knowledge in clear terms, and recognizing 
 the fact that we frequently encounter several of these causes in activity 
 together, we can investigate with interest the mixed forms of diathesis 
 which result. We do not embarrass ourselves by admitting extraneous 
 complications based on the peculiarities of race. Making due allowance 
 for acclimatization, we assert that, within certain limits, — not wholly 
 unimportant, but relatively very much so — the various causes of disease 
 act in the same way on individuals of very different races. It is in this 
 direction, if I am not mistaken, that the work of the future wiU be 
 done. We shall see that the connection between special diseases anci 
 the external coniiguration of the body is less close than has been as- 
 sumed, and that the best plan is to study carefully the scope of power 
 of each kind of morbid influence under the varied circumstances which 
 may attend its action. 
 
LECTUEE II. 
 
 Me. Peesidekt akd Gektlemen", — "We concern ourselTes to-day with 
 some of the most remarkable facts in respect to what is known as Idio- 
 syncrasy. In the definitions which were attempted in the previous lec- 
 ture it was fully admitted, nay insisted on, that this word is intended 
 to denote our ignorance of causes, though in no degree to express dis- 
 helief in their existence. Probably this ignorance will be, in most' in- 
 stances, only temporary, and the results which we need assign to idio- 
 syncrasy and leave thus unexplained will, one by one, be transferred 
 to the domain of the several diatheses concerning the causes of which 
 something,' at any rate, if not all, is known. Idiosyncrasy is, indeed, 
 to a large extent, nothing but diathesis brought to a point. It is pecu- 
 liarity of constitution in some one particular feature developed to a 
 height which at first sight seems inexplicable and possibly almost absurd. 
 It is individuality run mad. In seeking to understand the real nature 
 of that with which under this name we have to deal, we must keep in 
 mind that it is by no means always the isolated phenomenon which at 
 first sight it appears. For one man who rises to the height of pecu- 
 liarity which deserves the name miser, there are a thousand in whom 
 the quality of thriftiness is developed in various degrees beyond what is 
 praiseworthy. 'The miser is only the thrifty man developed in great 
 excess. So it is with the relations between diathesis and idiosyncrasy; 
 for one person who cannot take the smallest dose of quinine there are 
 thousands who betray unusual susceptibility to the drug, and many of 
 them in high degrees. Here, I think, we gain an insight into the way 
 in which idiosyncrasies possibly take their origin.- They are diatheses, 
 or parts of diatheses, developed, intensified, and specialized by heredi- 
 tary transmission. That they depend upon structural peculiarities we 
 cannot doubt, although we may be quite unable to demonstrate their 
 
 physical cause. The man who is poisoned by a drop of atropine solution 
 
 19 
 
20 THE PEDIGKEE OF DISEASE. 
 
 applied to his conjunctiva is as certainly the subject of some peculiarity 
 in his nervous organization as are those who cannot distinguish red 
 from green, or those who are born without the sense of hearing. 
 
 It may here be remarked that the term idiosyncrasy is not, I think, 
 ever applied to acquired peculiarities, but solely to those that are con- 
 genital. Some, perhaps, may. be overcome; many, as age advances, 
 undergo modification, but, as a rule, all are present at birth, and persist 
 through the whole of life. It is probable that all, when once devel- 
 oped, are hereditarily transmissible, and I am obliged to believe strongly 
 that if inquiry were made we should, in almost all instances, find that 
 all strongly-marked idiosyncrasies had been present in some degree in 
 former generations. I suggested in last year's lectures, and with, I 
 think, much plausibility, that the haemorrhagic diathesis — so strongly 
 hereditary when once produced, unknown in the lower animals, and 
 frequently coincident in the individual with gout — has its origin in 
 the peculiarities of vascular structure which are developed by gout, 
 and which have become modified and specialized by transmission 
 through many generations. So I would venture now to ask consid- 
 eration for similar hypotheses in reference to the other forms of 
 idiosyncrasy of most, or of all, of M'hich every fragment of genealogy 
 has been lost. 
 
 We have defined idiosyncrasy to be a peculiarity of the individual, 
 usually a rare and exceptional one, which does not necessarily entail 
 any degree of proclivity to disease, but which may become obvious under 
 a variety of exciting causes. It is often much as if by the introduction 
 of some test solution, a chemist should discover the presence of chloride 
 of sodium, or some other salt, in water which he had had no reason 
 previously to suspect. The various incidents of life in connection with 
 diet, drugs, and the exposure to the ordinary causes of disease, apply 
 these tests for us, and most unexpected revelations do they sometimes 
 make. We find that an individual apparently m no respect different 
 from those around him, is poisoned by the smallest quantity of some or- 
 dinary drug, or that he cannot digest some one article of diet which is 
 daily food to his companions; or, again, that the virus of some specific 
 fever either produces on him no apparent effect, or may be attended by 
 symptoms of tenfold their usual violence. Sometimes it is an extra- 
 
ON IDIOSYNCRASY OF STEUCTUEE. 21 
 
 ordinary immuniby which is revealed, and sometimes an almost incredi- 
 ble degree of susceptibility. 
 
 We can never predicate anything as regards idiosyncrasies of function 
 until the trial has been made. There are, however, a certain class of 
 individual peculiarities of the same nature which do not always remain 
 concealed. I allude to those in which the structure of some external 
 and visible organ is affected. The peculiarities which we have hitherto 
 classed as idiosyncrasies concern function only. But a moment's con- 
 sideration will make it evident that they must depend on structure, and 
 that they have really exact parallels in certain congenital defects or pecu- 
 liarities in external organization, which may or may not entail incon- 
 venience to the individual. A coloboma of the iris is a structural idio- 
 syncrasy, so also is the persistence of the nerve sheath in the retinal 
 nerve fibres in the human eye, which the ophthalmoscope occasionally 
 reveals. And each of these peculiarities may, indeed, must, entail some 
 degree of deviation from the normal condition of vision. It is true that 
 some congenital defects of structure occur in such an irregular manner 
 that we prefer rather to class them, at any rate for the present, as mere 
 accidents of development, or freaks of nature, than as idiosyncrasies, 
 such are, for instance, moles, nsevi, and the like. In the idiosyncrasies, 
 however marvellous some of them may be, there is usually to be noticed 
 a certain reference to law and order. They do not occur absolutely by 
 chance, and they often appear to be correlated with other less startling 
 peculiarities, and they often happen to several members of the same 
 family, or are distinctly hereditary. I have instanced coloboma of the 
 iris as an example of congenital idiosyncrasy of structure, and by its side 
 I might put hare-lip, clefts in the eyelid, absence of the levator palpe- 
 bree, and many similar defects. 
 
 These congenital peculiarities of structure which do not entail any 
 tendency to advancing disease of the whole organization, but remain 
 permanently local, and must, therefore, rank as idiosyn rasies rather 
 than diatheses, are not always apparent at the time of birth. Thus, a 
 child may be born with its skin, so far as can be observed, in a healthy 
 condition, but in whom within a few months of birth a harshness will 
 be noticed which will steadily develop itself into the typical condition 
 of ichthyosis. If this happened to but a single child in a family we 
 
22 THE PEDIGREE OF DISEASE. 
 
 might search about for some cause of disease to which the infant had 
 been subjected. But, if it happens to child after child in the same 
 family, we cease our quest in this direction, and begin to feel certain 
 that it must depend upon some congenital peculiarity in the structure 
 of the skin itself. 
 
 Permit me next to ask your attention in some little detail to two 
 groups of facts recently brought under my notice which will illustrate 
 my argument. Mr. Balmanno Squire was kind enough last autumn to 
 bring for my inspection a series of cases of most unusual interest. Very 
 briefly the facts were these. Three children from the country, two 
 sisters and a brother, of apparently healthy parentage, and having 
 several other brothers and sisters who ailed nothing, were themselves 
 the subjects of a malady the precise counterpart of which I had never 
 seen before. It was exactly alike, with some minor differences of 
 degree, in all the three children. Had it been a congenital deformity 
 or arrest of development, its occurrence in several members of the same 
 family would have been nothing remarkable, and we should ha\e been 
 able to place it, without any fresh wonderment at the marvels of patho- 
 genesis, by the side of ichthyosis, color-blindness, deaf-mutism, and 
 other well-recognized family diseases. But the malady in question by 
 no means fitted closely with these. It had not been congenital in any 
 one instance, but had developed in each child some years after birth. 
 It consisted in an inflammation of the skin of the face and upper ex- 
 tremities, which had covered them with crusts and scabs, and which on 
 some parts of the face, the nose especially, had caused ulcerations ex- 
 actly like lupus. In fact, any one seeing the nose only would have had 
 no hesitation in naming the disease lupus. But on the arms it was dif- 
 ferent. Here tnere was no evidence of new growth and very little of 
 ulceration, but simply a diffuse, more or less pustular inflammation. 
 From the occurrence of the disease on those parts most exposed to the 
 air it was to be assumed that such exposure was the exciting cause. As 
 it had not materially varied with season, and as the feet had not suffered 
 from chilblains, we may conjecture that the irritating influences were 
 wind and sun rather than direct cold. Let it be noted that in each of 
 these three cases the disease had persisted for several years, and, allow 
 me to repeat, that in all three children it was essentially alike. 
 
OK IDIOSYKCKASy OF STEUCTUBE. 23 
 
 What a lesson have we here as to the possihilities of hereditary dia- 
 thetic proclivity ! It may easily be the fact that not in the whole 
 population of the British Isles, at the present moment, another case 
 could be found which should offer anything approaching at all closely 
 the disease I have described; and yet it had been possible, in the cases of 
 three children, for the influence of parental combination of tendencies, 
 to be so definite and so peculiar, that they all developed it in precisely 
 the same form. I have already mentioned ichthyosis as affording us an 
 example of a disease which is often met with unexpectedly in many 
 members of the same family, and probably, after all, it affords us the 
 nearest parallel which we can find to these cases. It, however, in 
 greater or less degree, is tolerably common, and generally there is 
 some history of its having happened in former generations. It, too, 
 is very often congenital, or if not actually present at the time of birth, 
 it develops so soon afterwards, that we can easily believe that at any 
 rate the peculiarity of skin giving tendency to it was congenital, and 
 was of the nature of an arrest in the perfection of development. In the 
 cases which I have described, however, the miad less easily grasps such 
 an hypothesis, the disease being distinctly of an inflammatory kind, not 
 affecting the whole surface, and not beginning until a considerable period 
 after birth. Ichthyosis, for the most part, appears to be independent of 
 local exciting causes, though it is by no means wholly so; and we must re- 
 member that in Mr. Squire's cases, although local causes are clearly influ- 
 ential, they have been so trivial in amount that we are obliged to place 
 the inherited proclivities of the tissue in by far the foremost positiojn. 
 
 Inherited proclivity of tissue of a similar kind, that is giving tendency 
 at a certain age, under very insignificant exciting causes, to definite and 
 peculiar forms of infiammation is probably a thing which we very frc: 
 quently encounter in practice, but it is not often that we can demon- 
 strate its reality in such a striking manner as Mr. Squire's series of cases 
 enables us to do. It is chiefly on this account, although in itself an 
 extreme rarity, yet teaching us a wide lesson, that I have thought it 
 worth your attention. "When we see tubercular disease of the lungs 
 manifest itself in one after the other of a number of brothers and sisters 
 without obvious cause and run its course in each unchecked by treat- 
 ment, we probably witness an illustration of the same pathological law, 
 
24 THE PEDIGEEE OF DISEASE. 
 
 It is to be remembered further that, although it is only when several 
 members of the same family show tendency under the same circum- 
 stances to disease of the same part that the doctrine of inherited pro- 
 clivity of tissue is strongly enforced, there is yet every reason to believe 
 that the same cause is operative in countless examples of disease oc- 
 curring only in single individuals. During the winter session just past 
 two series of remarkable examples of xanthelasma in children, and in 
 several members of the same family at the same age, have been brought 
 before the Pathological Society. In one of these two brothers and a 
 sister, now adults, were shown by Dr. Stephen Mackenzie, all three the 
 subjects of xanthelasma in a slight but definite form, and all with the 
 history that it had been noticed at birth. Mr. James Startin showed a 
 brother and sister, still young children, in whom similar conditions were 
 present in much more conspicuous forms, and in whom they had been 
 noticed within a few years of birth, but were believed not to be con- 
 genital. In all these cases the changes are symmetrical, and occur in 
 the limbs, neck, and trunk, omitting that part most usually affected 
 when the disease develops, de novo, in adults, namely, the eyelids. • In 
 none is the affection attended by any derangement of general health, or 
 tendency to liver disorder, and it seems probable from Dr. Mackenzie's 
 cases that there is no tendency to increase, the three patients, now 
 adults, having been in their present condition from early childhood. 
 Thus, the general features of the malady differ exceedingly from those 
 of the more common form as we see it in adults, and approach those of 
 some other forms of skin disease — psoriasis and ichthyosis, for example. 
 Histologically, however, the local changes in those cases are those of 
 xanthelasma, and as such we must class them. In Mr. Startin's case 
 the resemblance to psoriasis, as regards symmetry and location of patches 
 on the tips of the elbows, etc., was very marked. 
 
 If speculation respecting such rare conditions may be permitted, I 
 think it should proceed somewhat on these lines. We know, respecting 
 psoriasis, that it is very hereditary, persisting through many generations, 
 but rarely showing itself in more than a single member of the same 
 family, and not unfrequently undergoing apparent transmutation into 
 other forms of skin disease, as, for instance, nummular eczema, lichen 
 ruber, pemphigus, and ichthyosis. 
 
ON STETJCTURAL IDIOSYNCRASY. 25 
 
 Of its connection with the latter malady — parents the subject of 
 psoriasis having ichthyotic children — I adduced some evidence in my 
 last year's course of lectures. Of ichthyosis itself we know that it usu- 
 ally occurs in several members of the same family, is hereditary, but 
 often omits a generation, or fails to descend in the direct line. Xan- 
 thelasma we have as yet known only as a disease which occurs chiefly on 
 the eyelids of adults who have suffered from liver disorder, and which 
 hardly ever in adults develops on other parts of the skin, excepting when 
 in connection with jaundice. It is in part a new growth, and in part a 
 fatty degeneration, and its peculiarities as regards color, etc., clearly 
 have a close connection with the presence of bile pigments in the blood. 
 I do not think that there can be much dispute as to the possibility of 
 inheritance of any tendency to tissue change which has existed for a 
 long time in the individual who was its first subject, and in whom it 
 had showed itself a considerable time before the birth of ofEspring. Xor 
 is it in the least certain, perhaps not even probable, that such heredi- 
 tary tendency would be manifested in the first generation. If we apply 
 these facts to the explanation of the occurrence of xanthelasma as a 
 family, and almost as a congenital disease, apparently of no diathetic 
 significance, I think we should conjecture that it is probably derived 
 from some progenitor who had acquired the ordinary hepatic form of 
 adults. And further, I cannot help the suggestion that it is possible 
 that this inheritance, has met and combined with a degree of proclivity 
 to that group of skin diseases of which psoriasis is the best type. 
 
 Let me recapitulate: If a child shows within a year or two of birth 
 yellow tubercles on its elbows, and delicate yellow streaks and spots in 
 the flexures of the hips and popliteal spaces, exactly such as we are 
 familiar with in connection with severe jaundice in the adult, and with 
 jaundice only, we at first seek for evidence of disease of the liver. But 
 if we find similar conditions produced at about the same age in two or 
 three members of the same family, and the same series of events hap- 
 pening in more- than one family, we again, as in the case of ichthyosis, 
 cease our search for the ordinary causes of the disease, and fall back 
 upon the hypothesis of what I have ventured to term structural idiosyn- 
 crasy. We feel sure that the skin of the parts affected must have been 
 at birth in a state of peculiarity, although we failed to be able to prove 
 
26 THE- PEDIGREE OF DISEASE. 
 
 it. It is, of course, possible that the congenital peculiarity was not in 
 the skin alone. It may have been in the blood also; but if we observe, 
 in the subsequent life of the patient, that the peculiar conditions remain 
 restricted to the parts first affected, that they have no aggressive power, 
 and that the general health of the individual does not suffer in the least, 
 our first impression as to the idiosyncrasy being purely one of local 
 structure becomes revived and strengthened. 
 
 I am yet very anxious to make clear the argument that congenital 
 structural peculiarity may entail liability to local disease, and that such 
 disease may be locally aggressive — at any rate, for a certain time, perhaps 
 indefinitely — because I think it is one which may, probably, explain a 
 large class of pathological facts, some of which are of a far less definite 
 character than those to which we have just referred. Let us use icthy- 
 osis and xanthelasma of young children as definite and palpable illustra- 
 tions of what is possible, although admittedly rare, and guided by the 
 light which we obtain from their investigation, let us examine the facts 
 as to some other much less definite maladies. In the condition known 
 as molluscum fibrosum, little tumors — possibly fibro-cellular, possibly 
 glandular — develop in or under the skin. Usually there are very few 
 of them, and examples of the malady, when only two, three, or half-a- 
 dozen are present, are very common. In rare cases, however, the whole 
 surface is affected, and the tumors may be counted by hundreds, or even 
 thousands. The tendency to their production may be noticed for the 
 first time at almost any period of life, but if they are to be numerous, it 
 begins almost invariably in early childhood. Whether there be many, 
 or whether there be fewj the general , health remains good, and there is 
 no evidence whatever of any correlated tendency to general disease. Is 
 it not very probable that the liability to molluscum fibrosum is inbred 
 in the original development of the integument, that we are witnessing 
 the results of an idiosyncrasy of structure ? Let us see how the matter 
 stands as regards common psoriasis. In this instance we have no new 
 growth of tumors, but only a tendency on the part of special regions of 
 the skin, possibly of almost the whole of it, to take on a certain peculiar 
 type of chronic inflammation. This tendency occurs in its best marked 
 forms, and most frequently to young persons, although, let us note, it 
 is never congenital, and never even infantile. It is never associated 
 
ON STRUCTURAL IDIOSYNCRASY. 27 
 
 with anything that we can appreciate as ill-health, and the facts with 
 which we are acquainted as regards the conditions which may influence 
 it for the worse, are few and insignificant. Excepting so far as it may 
 he supposed to act by interfering with the functions of the skin, it does 
 not produce any derangement of the patient's health. It is hereditary, 
 but not prone to prevail in many members of a single family. Is it not 
 probable that a disease, of which these statements are true, is one not 
 originally or whqlly due either to the blood or to the nervous system, 
 but in 'large, and chief part, to an idiosyncrasy in the structure of the 
 skin? In proportion as the disease is late in its development— in other 
 words, in proportion as we find it apparently waiting for the exciting 
 influence to assist its birth — may we assume the probability that the 
 idiosyncrasy is less strong. The explanation of the entire absence of 
 psoriasis in infancy and early childhood may possibly be found in the 
 suggestion that, when the structural idiosyncrasy is very strong, it mani- 
 fests itself in a different form. Thus, I think it not improbable that 
 ichthyosis of infants may be in this way the representative of the psoria- 
 sis tendency in its intensest form. I must not weary you in arguing the 
 case in reference to other diseases of the skin, or of other parts, but 
 simply state that whenever we find a strictly local malady which de- 
 velops itself in all instances with little or no apparent cause, is heredi- 
 tary, is but little aggressive, and only in a sort of accidental way influ- 
 ences the health of its subject, we are entitled to suspect structural idio- 
 syncrasy. Steatomata on the scalp, lipomata, adenomatous tumors in 
 the breast, multiple uterine fibroids, milium, whether on the face or 
 elsewhere, and a host of others, are probably examples of what I have 
 tried to describe. From these it needs but little ingenuity to perceive 
 that it is only a matter of degree if we should pass to the development 
 of new growths in general, both malignant and innocent, and to many 
 disorders which do not fit at all exactly with the description which I 
 have given and concerning which we can say a good deal as to our 
 knowledge of their exciting causes. In a multitude" of these, heredi- 
 tary, but wholly latent, peculiarity of structure may not improbably 
 take its share in the production of the special result. They are ex- 
 amples of what may be termed complicated or conditional idiosyncrasy. 
 I must hasten to other departments of our subject. As surgeons we 
 
28 THE PEDIGREE OF DISEASE. 
 
 have to encounter the results of functional idiosyncrasy chiefly in refer- 
 ence to drugs and the specific fevers. The department of diet I ought, 
 perhaps, to leave to physicians, yet it is impossible that I should wholly 
 do so. For the patients who consult us about other maladies will often 
 describe to us symptoms which we should wholly misinterpret were we 
 not familiar with what is possible in reference to diet idiosyncrasy. A 
 few, years ago it fell to my lot to become much interested in the subject 
 of idiosyncrasy as regards eggs. Several patients consulted me within a 
 short period, who, amongst other symptoms, described a liability to 
 attacks of violent vomiting, or of a sense of sinking and abdominal dis- 
 tress which were to them inexplicable. In more than one of these the 
 reason of my being consulted was that the attacks were attended by 
 temporary defect in sight. In one instance the patient was an artist, 
 who declared that frequently he was quite unable, for several hours at , 
 a time, to see to paint. His defect seemed to be a temporary suspen- 
 sion of the power of accommodation. It always affected both eyes, and 
 was always attended by a sense of heat at the stomach and abdominal 
 discomfort. I found that these attack usually occurred within an hour 
 or two of breakfast, and on entering into detail I became convinced 
 that they were due to eating eggs. On telling my patient my conclusion 
 he replied at once that he had always suspected it, yet being very fond 
 of eggs, he had indulged in one once in a month or so. He was quite 
 cured by abstinence. In several of the cases to which I refer, the 
 symptoms produced were far more violent than in this one, and had 
 been so severe on some occasions as to lead to the suspicion that poison 
 had been given. In some cases susceptibility as regards eggs is observed 
 in reference to all eggs, and in all conditions as regards freshness, and 
 in respect also to the very smallest quantity, so that a little egg taken in 
 a pudding, a sauce, or a soup, may produce the most definite disagree- 
 ment. In some the susceptibility is invariable, but in others it may be 
 much diminished, or entirely removed when its subject is in unusually 
 good health, or taking much exercise in the open air. In many in- 
 stances the liability to egg-poisoning is manifested only in respect to the 
 eggs of certain birds, or eggs under certain special conditions as regards 
 cookery or keeping. Eggs and fish, the two articles of diet respecting 
 which most is to be said as regards peculiar susceptibilities, are, it is to 
 
IDIOSYNCKASY IN BEFERENCE TO EGGS, TEA, ETC. 29 
 
 60 remembered, the two whicli are most easily capable of peculiar 
 changes from over-keeping. A fish which is quite wholesome when ab- 
 solutely fresh may become exceedingly otherwise if kept only for a few 
 hours after death, a fact with which those who live in hot countries are 
 abundantly familiar. The same is true, though to a less extent, in 
 respect to eggs. Eggs are perhaps as much influenced by methods of 
 cooking as by mere keeping, and I may remark in passing that the ex- 
 amples of the most violent egg-poisoning which I have known have oc- 
 curred to individuals who, having manifested the idiosyncrasy to some 
 extent at home, had incautiously partaken of articles containing eggs 
 whilst travelling abroad. Amongst various other articles of diet re- 
 specting whicli peculiar susceptibilities are frequently shown, we have 
 honey, tea, coffee, various fruits and vegetables, and various forms of 
 alcoholic beverages. Oases of what deserve to be known as tea-poisoning 
 arfe probably by no means infrequent, but the medical adviser who, hav- 
 ing become cognizant of some of these, should straightway proceed to 
 discourage the use of this beverage by all, would be making a very wide 
 departure alike from the laws of clinical induction and common sense. 
 We have to deal with idiosyncrasy, and must apply our knowledge 
 under the limitations of its laws. It must be remembered, however, as 
 I have already asserted, that idiosyncrasy by no means declines to enter 
 into partnership with other causes of functional disturbance more easy 
 to be understood. The varying state of the patient's health at different 
 periods of life, and varying habits as regards diet at different times, may 
 conceal or bring into unusual prominence an idiosyncrasy which is itself 
 a permanent condition. In many patients susceptibility to the influ- 
 ence of tea is much increased by taking certain wines, notably cham- 
 pagne, and is diminished by malt liquors and the red wines. As a 
 rough rule, all idiosyncrasies become aggravated when the tone of the 
 System is low, and many of them pass into almost absolute abeyance 
 under conditions of unusual vigor and health. 
 
 Idiosyncrasy in respect to tobacco displays itself in two forms, and 
 one of them is of unusual interest, since it exemplifies a class of idio- 
 syncrasies which are very apt to be misunderstood. I refer to those in 
 which the individual susceptibility is not displayed immediately on the 
 incidence of the exciting influence, but waits, it may be, for a long 
 
30 THE PEDIGEEE OF DISEASE. 
 
 time, and until possibly other conditional, causes come to its assistance. 
 A little thought will probably supply most of us with examples of this 
 class of idiosyncrasies, and they are very important in practice. A man 
 who has di'unk tea all his life, and largely, may rather suddenly find 
 that it is almost poisonous to him, and may then recollect that one or 
 more of his relations have never from childhood been able to take it. 
 It is the same with eggs, fish, and certain kinds of wine, and so also 
 •with various drugs, and in all these instances it is, I believe, quite possi- 
 ble that the display of the idiosyncratic susceptibility may be only tem- 
 porary. In some instances we may discover in some change in the mode 
 of life or habits of diet, or in advancing age and possibly some visceral 
 degeneration, an explanation of the newly-discovered peculiarity, but in 
 other cases nothing can be found. 
 
 Tobacco, I think, stands curiously alone amongst the articles in 
 human use in that it almost invariably in the first instance acts as a 
 powerful poison, and that tolerance can be acquired quickly and cer- 
 tainly by almost every one. There are, however, great differences in 
 the degree of susceptibility, and in the ease with which habituation is 
 obtained. Many never do obtain it, and although this in most cases 
 may be merely the result of want of perseverance, there is a certain 
 number in whom it would appear that the primary idiosyncrasy is in- 
 superable. Many persons who have acquired tolerance of one kind of 
 tobacco remain susceptible to others, and after having been habitual 
 smokers for years, may be made very ill by inadvertently using an un- 
 accustomed kind. Many smokers, I believe, recognize periods during 
 which the pipe disagrees with them, and they are obliged for a time to 
 abandon it, and very curious symptoms, such as absolute suspension of 
 the sexual appetite, etc., are sometimes with confidence alleged as con- 
 sequences of its excessive use. But the cases which are of most interest 
 in connection with our present subject are those in which without any 
 excess and in persons who have been for long thoroughly habituated, 
 tobacco suddenly begins to act as a poison without causing any distaste 
 or any conspicuous derangement. These patients are often quite una- 
 ware of what it is which is hurting them. They lose appetite and 
 become nervous, and amongst the most conspicuous symptoms is a very 
 marked failure of sight. This failure differs from all other forms of 
 
TOBACCO AMAUROSIS. 31 
 
 amaurotic amblyopia. It alw3.ys affects simultaneously and equally both 
 eyes; it begins very insidiously, and having no other symptom than 
 diminution in acuity of vision, is often scarcely recognized by its subject 
 until at the end of six weeks or two months he finds that he can only 
 read the largest type. When at its height the optic disc is usually red 
 and a little hazy, and at a later stage it becomes decidedly pale. If the 
 patient will for a while leave off smoking he will regain his sight almost 
 to a certainty, but, however perfect may be his apparent recovery, the 
 disc is almost always left pale. He may resume the habit after awhile 
 without much risk of relapse if he keeps to strict moderation, and in 
 some cases recovery takes place, although the abstinence has never been 
 complete. 
 
 Such are some of the principal facts respecting Tobacco Amaurosis. 
 I have felt justified in stating them in this positive manner because I 
 published in a series of reports some years ago in the ' Ophthalmic 
 Journal ' and the Koyal Medical and Chirurgical Society's ' Transac- 
 tions ' very full details respecting them. That the symptoms in ques- 
 tion are really due to tobacco I cannot feel the slightest doubt. I have 
 seen no cases quite parallel to them either in women or in non-smoking 
 men. If in these two classes of patients similar symptoms should be 
 presented, which is very rare, I believe that they always progress with- 
 out interruption to almost total blindness. Tobacco amaurosis rarely 
 happens to novices in smoking, and seldom except to those who are 
 liberal in the indulgence. Half an ounce of shag per day has been the 
 usual allowance in the cases which I have collected. In support of my 
 interpretation of the facts I may briefly advert to the history of our 
 knowledge of them. Long before the ophthalmoscope-diagnosis was 
 made out. Dr. Mackenzie, of Glasgow, and several French observers, 
 hal recognized the malady, and alluding to the difficulty met with in 
 persuading its subjects to abandon the habit. Dr. Mackenzie had used 
 the expression, " There are many who would rather smoke than see." 
 Mr. Wordsworth, at Moorfields, was, I believe, one of the first who 
 studied the opthalmoscope-diagnosis, and he held that the conditions 
 displayed by the disc were pathognomonic. It was to his teaching that 
 I was chiefly indebted for my first interest in the subject. 
 
 I must hasten to the narration of certain facts which show that this 
 
32 THE PEDIGREE OF DISEASE. 
 
 disease is really a matter of idiosyncrasy, and that we ought, by recog- 
 nizing this fact, to explain the circumstance that such a very small pro- 
 portion of smokers ever suffer from it. This immunity of the greater 
 number and the picking out of one here and one there has been a great 
 stumbling-block to many in the way of accepting this doctrine. I 
 cannot think that it ought to have been so if' due allowance be made 
 for the influence of idiosyncrasy. The facts to which I first alluded as 
 supporting the belief that this influence is really at work are the follow- 
 ing :^Not very unfrequently the subject of tobacco amaurosis is one 
 who was well aware of his susceptibility, who had experienced unusual 
 difficulty in learning to smoke, and who had never been able to change 
 with impunity from one kind of tobacco to another. Some years ago a 
 young man came under my care who was a smoker, and who had 
 smokers' amaurosis. Subsequently his mother, who did not smoke, 
 came to me for an almost similar state of things, and I then learned 
 that a nephew of hers, a smoker, had sufEered just like his cousin, and 
 had been under the care of my colleague, Mr. Hulke. I applied to Mr. 
 Hulke for his diagnosis, and he kindly sent me a copy of his notes, 
 showing that he had considered it a tobacco case. Here, then, we have 
 three near relations presenting the same form of disease. In the 
 woman, who did not smoke, the disease did not show itself until twenty 
 years later in life than in the two young men who did, and in them, on 
 abstinence, the disease was arrested, whilst in her, in whom no change 
 of habit could be made, it increased. Can we doubt that we have here 
 an instance of family proclivity ? ^ 
 
 I have yet to mention a stronger case in proof that special suscepti- 
 bility may exist in a family. A hard-worked Welsh clergymaa, had 
 been accustomed to irregular meals and had consumed, in large quanti- 
 ties, a cheap, strong tobacco. He became nervous, and almost blind, 
 and he recovered on giving up smoking. He told me subsequently that 
 two of his brothers, farmers, had experienced precisely similar symp- 
 toms, and apparently in connection with the same cause. I did not see 
 either of them, but I believe both were, like himself, almost wholly 
 cured by abstinence from smoking. These two groups of cases, in each 
 of which more than one member of the same family suffered from the 
 same cause, bear to my mind very strong evidence in favor of the 
 
IDIOSYNCRASY IN REFERENCE TO ARSENIC. 33 
 
 opinion that it is under the laws of idiosyncrasy that we must seek the 
 explanation of chronic tobacco poisoning. It occurs to those in whom 
 the nervous system, possibly the nervous tissue, has susceptibilities 
 which are not shared alike by other members of the community. I 
 have alluded to the fact that this susceptibility is not usually simple or 
 immediate, as in the case of arsenic; it is almost always in those who 
 have been long accustomed to smoking that these nerve phenomena 
 occur, and they are probably indicative of a state approaching to satura- 
 tion. If it be asked what are the other contributory causes which assist 
 in producing the outbreak, I should be inclined to suggest that very 
 varied influences which reduce tone may help; over- work and anxiety 
 may assist, and so probably may the sudden loss of outdoor exercise. I 
 do not think that the use of stimulants is often a contributory cause, at 
 any rate, not unless to such excess as to interfere with appetite for food. 
 Many facts which have come under my notice suggest that total ab- 
 stainers from alcoholic beverages are, if they smoke freely, in much 
 more danger of chronic tobacco-poisoning than those who drink them. 
 
 Eespecting idiosyncrasies as regards Arsenic, I have to remark that 
 they are not nearly so marked nor so common as those respecting soine 
 other drugs. I have met with exceedingly few cases in which small 
 doses disagreed. It is very exceptional indeed that a patient complains 
 of inconvenience at the outset of a course. Usually, symptoms occur 
 after the drug has been to some extent pushed, and they for the most 
 part necessitate its discontinuance or reduction. I am alluding now to 
 the well-known symptoms of conjunctival irritation and pain in the 
 stomach and bowels. Eespecting these, I think, tolerance is never ob- 
 tained, and if once they have occurred they are prone to occur again if 
 the same doses are given. In English practice, individual susceptibility 
 to arsenic does not seem to vary much. Most persons, as I have said, 
 can take it, and very few can take more than a certain dose. I have 
 never myself seen a case in which it could be pushed beyond a certain 
 point without definite disagreement. The most remarkable fact in 
 reference to idiosyncrasy is its occasional production of the form of 
 - neuritis which we know as herpes zoster. It is now more than ten 
 years since I published a series of cases illustrating the occurrence of 
 
 herpes zoster in patients who were taking arsenic, and since then I have 
 3 
 
34 THE PEDIGREE OF DISEASE. 
 
 seen so many other examples of it that I cannot entertain the slightest 
 doubt as to the direct connection between the two. The herpes erup- 
 tion may occur in the forehead, face, or trunk, and it is wholly indis- 
 tinguishable from the herpes in these regions which is not due to arse- 
 nic. It runs the usual course and disappears after its normal duration, 
 whether the arsenic be continued or not. The patient does not, as a 
 rule, show any constitutional symptoms of arsenic intolerance, and it is 
 almost invariably the case that he has taken the drug for some weeks, 
 before the symptom appears. The advent may now and then be delayed 
 until a week or ten days after the course has been suspended. A pre- 
 cisely similar interval is sometimes seen in cases of sympathetic ophthal- 
 mitis, in which affection — probably, also, a form of neuritis — the in- 
 flammation of the second eye may begin to develop a week or ten days 
 after the entire removal, by excision, of its cause. These facts would 
 suggest that the neuritis is in each instance slow in its stages, and that, 
 having been once initiated, its local processes cannot be stopped. The 
 number of those who show arsenical herpes is very small in proportion 
 to those who escape, and, if it is to occur at all, I think it always 
 happens during a first course. I have never seen it in a patient who 
 had been accustomed to the drug for a long time. Thus, its occur- 
 rence must cfertainly rank as the result of an idiosyncrasy; and this 
 suggestion opens the way for the further one — that we ought, perhaps,. 
 always to regard herpes zoster as, in the main, an indication of personal 
 peculiarity. It certainly does not appear that all persons are equally 
 liable to it, since it happens to but very few, and is never associated 
 with any special form of ill-health. Excepting the single fact, Just al- 
 luded to, of its occasional production by arsenic, we know of no causes 
 which can evoke it. I have seen arsenic produce herpes in two different 
 regions at the same time, but I do not remember to have ever witnessed 
 a second attack in the same individual. In reference to this, however, 
 it is but fair to add that I have usually carefully avoided this drug after 
 aa attack of shingles, since the latter is often a very serious trouble. A 
 few persons — a very few — are liable to the occurrence of an eruption of 
 herpetic vesicles over and over again in the same part of the skin, and, 
 as is well known, examples of recurring herpes on mucous membrane 
 are common, as, for instance, on the lips and genitals. Sometimes re- 
 
IDIOSYNCRASY IN KEFEEENCE TO ARSENIC. 35 
 
 currences take place once a month, or even oftener, tlie eruptions always 
 passing through the usual stages, and undergoing a speedy and sponta- 
 neous cure. There is never any peculiarity of health to be made out in 
 explanation of these cases, and they must, I suppose, rank as idiosyn- 
 crasies. Homceopathists are welcome to make what use they can of the 
 fact that arsenic will often cure these cases and prevent the recurrence. 
 [ have repeatedly seen herpes of this kind remain in abeyance for many 
 months whilst the patient was taking arsenic, and show itself again 
 when the drug was suspended. I have seen one case which to some 
 extent ofEers an exception to some of the statements which I have just 
 made, inasmuch as the patient was liable repeatedly to an eruption from 
 arsenic. The eruption always came soon after beginning the remedy, 
 and he was well accustomed to its use. The patient is a gentleman 
 now near to sixty, who has suffered from psoriasis most of his life, and 
 for whom in early life Sir Benjamin Brodie prescribed arsenic. He has 
 often taken it since, and its usual effect is as stated. On one occasion 
 he took it in order to show me the character of the eruption produced. 
 It had been called " ecezma," and, although it certainly had the local 
 features of an erythematous eczema, yet it occurred, like herpes, un- 
 symmetrically on one arm in large patches, which disappeared sponta- 
 neously after a few days. 
 
LEOTUEE III. 
 
 Mk. President and Gentlemen, — I hope I have made it sufB- 
 ciently clear that I am not purposing to trouble you with any list of 
 idiosyncrasies. As well fpr your relief as my own exculpation, it is 
 perhaps desirahle that I should again make this statement. What X 
 said about egg-poisoning in my last lecture was intended to suflBce as an 
 illustration of what is possible, indeed, I would suggest not infrequent, 
 in reference to a whole group of food-idiosyncrasies. The same remark 
 applies to the somewhat detailed discussion on the susceptibilities in 
 reference to tobacco. We are engaged in the examination of the laws 
 of idiosyncrasy, and not in any attempt to record exhaustively its facts. 
 I shall bring before you no more narratives of cases or statements as to 
 facts than may seem absolutely necessary to illustrate the general laws 
 to which we refer. In Monday's lecture we glanced briefly at certain 
 peculiarities of structure which are sometimes met with in external parts 
 which are both congenital and hereditary. For these I proposed the 
 name of structural idiosyncrasies, and asked that we should apply the 
 knowledge that we can easily gain respecting them to those which are 
 much more obscure, from the fact that they are betrayed only by de- 
 rangement of function. 
 
 I next alluded to certain forms of inflammatory disease not present at 
 birth, and in most cases not commencing until a considerable period 
 after it, but concerning which the general facts suggest that they must 
 be due to some inborn peculiarity of the structure implicated. Lastly, 
 I adverted to examples of complicated or secondary idiosyncrasy in 
 which the individual peculiarity is not displayed immediately on the 
 application of its exciting cause, but waits, as it were, for the co-opera- 
 tion of other influences. "We found one of our best illustrations of this 
 in the chronic poisoning, denoted chiefly by amblyopia, to which smokers 
 are in exceptionable instances liable. I concluded my lecture by a brief 
 
 allusion to idiosyncrasies in reference to arsenic, and was obliged by 
 
 36 
 
IDIOSYNCRASY IN RESPECT TO DRUGS, ETC. 37 
 
 want of time to defer till to-day what I have to bring before you on the 
 important subject of the iodides and similar salts. I shall be compelled 
 to omit altogether what I had prepared in reference to. belladonna, 
 opium, and certain other drugs, an omission which I shall regret the 
 less because, as just said, I am seeking only for illustrations of law and 
 of these perhaps we shall have enough. 
 
 The iodides and bromides offer us, indeed, such excellent and various 
 illustrations of the laws of idiosyncrasy that I am almost tempted to 
 wish that I had excluded all others, and thus secured more time for the 
 consideration of them. The modes in which these salts can produce 
 disagreement are exceedingly varied, and concern very different parts of 
 the system, whilst many of them are displayed by the skin in a manner 
 which permits of their easy identification and examination. Not even 
 the syphilitic virus itself is capable of producing a greater multiplicity 
 of pathological changes in the integument. Now it is a haemorrhage, 
 now a thrombosis, now an er3'thema, now a bulla; the commonest of all 
 forms is an acne, but in addition to it and those which I have named we 
 may have at the same time pustules, button-like tubercles, and in ag- 
 gravated cases enormous soft tuberous growths. 
 
 If time had permitted me I should have taken occasion to advert also 
 to a topic of much importance to us in operative practice, and should 
 have suggested that in a considerable number of the accidents with 
 anaesthetics it is idiosyncrasy which we encounter. Many of the deaths 
 from chloroform occur to persons apparently in perfect health, and 
 when only small quantities have been given and with every possible pre- 
 caution. Such cases ought probably to be placed side by side with 
 those in which individual susceptibility becomes unexpectedly revealed 
 to us in reference to such drugs as opium, belladonna, and the like. 
 We waste our labor when we search for proof of heart disease, or some 
 flaw in the apparatus, or some want of care in the administration. The 
 last patient in whom, under my own care, we came near to a fatal event 
 with chloroform, was a man at Moorfields, in whose case extraction of 
 cataract was about to be performed. He would certainly have died but 
 for the vigorous use of artificial respiration and the nitrite of amyl. In 
 discussing the case afterwards I was reminded by our house-surgeon 
 that three years before, when the other eye was operated on, the same 
 
38 THE PEDIGREE OF DISEASE. 
 
 man had caused us alarm by precisely similar symptoms. The occur- 
 rence had unfortunately been forgotten. It is probable that there are 
 persons in whom, owing to peculiarity of nerve organization, and not in 
 the least to anything which we can recognize as ill health, the inhalation 
 of chloroform will always cause an extreme depression of the heart's ac- 
 tion. In such, if the precaution of giving beforehand a dose of opium, 
 alcohol, or ether, be omitted, there is the utmost risk of a fatal event. 
 Probably each anaesthetic has its related conditions of idiosyncrasy. 
 
 I have passed over also another subject, owing to want of time, which 
 has considerable surgical interest. It is the influence of inherited 
 structural peculiarities in favoring the occurrence of lesions which at 
 first sight suggest no suspicion of such origin. Examples we have of 
 this in the easy occurrence of dislocation, owing to peculiarity in joint 
 formation; and the proneness to intussusception of the bowels, owing 
 to the CEeciim and ascending colon being provided with a mesentery. I 
 have several times known the tendency to intussusception show itself 
 in several members of the same family, and in one of the most marked 
 instances in which several of the children had died of it in succession 
 the condition referred to was found at the autopsy of one of them. 
 
 I now turn to the subject of the idiosyncrasies in reference to the 
 iodides and bromides. It seems probable that the difference in form 
 which the inflammation of the skin assumes is dependent upon the 
 peculiarities of the individual, for if the patient has shown a tendency 
 to an unusual development of the iodide rash on one occasion, and the 
 same salt be given to him on another, even after a long interval of time, 
 it will produce exactly the same effect. This I have witnessed repeat- 
 edly. Idiosyncrasies as regards the iodide are not manifested solely by 
 the skin, are perhaps not primary in it, and are seldom confined to it. 
 Congestions, with excessive secretion, of certain tracts of mucous mem- 
 brane, are of yet more frequent occurrence than are skin rashes, but 
 they differ from the latter in that they are, in a majority of instances, 
 only transitory. An eruption on the skin, once developed by the 
 iodide, persists — and indeed becomes increased — so long as the drug is 
 given; sometimes, even after it has been suspended. The iodide coryza, 
 as it is called, on the contrary, seldom lasts more than a few days; or if 
 it becomes chronic, always subsides into a slight affair. Thus the one 
 
IDIOSYNCRASY AS TO IODIDES. 39 
 
 would appear to imply idiosyncrasy in a far less degree than the other, 
 and this suspicion is borne out by the observation that in those who 
 suffer from any of the more serious forms of skin eruptions, there are 
 usually other evidences that the drug is producing injurious effects. 
 The tone of the nervous system is always lowered by it, and sometimes 
 to an alarming extent. There is, perhaps, no drug that can be men- 
 tioned respecting which idiosyncrasy is so common and variations in its 
 degree so great. I have repeatedly seen doses of only half a grain 
 produce, in the course of a couple of days, definite symptoms of poison- 
 ing; arid, on the other hand, I have known a patient swallow an ounce 
 and a half a day of the best Apothecaries' Hall iodide for a week together 
 without any special effect, except a feeling of lassitude and want of tone. 
 It is also very remarkable how, in a large majority of cases in which 
 definite and peculiar susceptibility is at first manifested, tolerance may 
 subsequently be attained, and doses of ten, twenty, thirty times the 
 amount given without obviouS effect. Probably there is no drug re- 
 specting which the assertion can be more easily demonstrated, that it is 
 not the dose, but its effect, which we should regard. It by no means 
 follows that because a patient has an idiosyncrasy against some drug or 
 article of diet, that we ought wholly to abstain from its use. Eather 
 this susceptibility, in the majority of cases, proves that in him minute 
 doses will effect the cure first as efficiently as larger ones in others. I 
 have repeatedly cured tertiary ulcerations of the throat and skin in pa- 
 tients in whom I was assured iodide was a poison in all doses, by giving 
 it in quantities of half, or even a third, of a grain. In the year 1863, 
 M. Bazin, of Paris, an excellent specialist, and at the same time an ex- 
 cellent physician, described a new disease under the name of Hydroa. 
 Of this malady he recognized several varieties, one like varicella, one 
 resembling smallpox. On reading M. Bazin's descriptions I was at once 
 struck by the closeness with which they applied to several cases which 
 had been under my own care, and in 1870 I wrote in the ' British 
 Medical Journal' a report on " hydroa," quoting M. Bazin's descrip- 
 tions, and recording my own cases together with others supplied to me 
 by my friends. I had previously been to Paris and seen M. Bazin's 
 models. At that time neither of us had any idea -of the usual cause of 
 the eruption, nor, I believe, had any of our readers or critics. One of 
 
40 THE PEDIGREE OF DISEASE. 
 
 the latter suggested that we had not named it correctly, and that it was 
 only an " urticaria bullosa," but in doing this he gaye us no clue to its 
 cause. At this date we all knew of the acne which so commonly results 
 from the iodide, but were not aware that this salt could in connection 
 with idiosyncrasy produce other symptoms so much more formidable. 
 In the session of 1869, Dr. Cholmeley brought before the Clinical 
 Society an example of & remarkable confluent eruption produced by the 
 bromide; several papers had also appeared in Paris on the subject, and 
 subsequently I convinced myself that almost all the examples of the 
 disease to which we had given a new name were really the bullous form 
 of the iodide eruption. From that time to this I have seen but very 
 few examples of "hydroa" except as the consequence of iodides or 
 bromides. It will be seen that we had made no error in observation, 
 but had simply described and named a disease which was new to us, and 
 new to medical literature, but of which at the time we had not dis- 
 covered the cause. When the cause was found the name became of 
 little importance. As already hinted, however, we have by no means 
 in mentioning the iodide acne, the iodide " hydroa," concluded the list 
 of symptoms due to- this drug. Eespecting a case which I have to men- 
 tion in the next group, I shall not be surprised if many remain still in 
 doubt as to whether it ought to be placed in this position. A man 
 came to me at the London Hospital covered with large soft tumors, 
 some of them as big as a child's fist. They occurred chiefly on his face, 
 chest, and limbs. That I may avoid a lengthy description, I will simply 
 refer you to the sketch which hangs on the wall, which is a rough copy 
 from an excellent drawing which I now display. It will be enough to 
 say that the moment I saw it I believed it to be an iodide eruption, and 
 that my diagnosis was based upon the recollection of other cases, un- 
 questionably due to that cause, which I had previously seen. The man 
 had just been discharged from another hospital, and on inquiry I found 
 that during his month's stay in it he had been steadily taking the iodide 
 in increasing doses the whole time. The eruption was not present in 
 the least before the drug was begun. The patient died, within a fort- 
 night of his admission under my care, from exhaustion, apparently due 
 to the extent of surface implicated. The post mortem revealed nothing 
 which threw further light upon the cause of his malady. It seemed 
 
IDIOSYNCKASY AS TO IODIDES. 41 
 
 probable that he had never had syphilis. He had gone into the hospital 
 on account of another complaint, and when the eruption appeared it 
 ■was considered to be syphilitic, and instead of suspending the remedy, 
 its dose was increased. The dose was, however, never more than fifteen 
 grains three times a day. To those who are still inclined to doubt 
 whether this terrible eruption was really due to the iodide — and I admit 
 I have no right to be surprised if the number comprises all my audience 
 — I would put the question, What else could it be ? The microscope 
 showed in the tubers only the results of common inflammation, and 
 there was nothing in the least suggestive of malignancy. Above all, I 
 would ask that a careful comparison be made with the other drawings 
 from another case which I have placed by its side. It will be seen that 
 the two closely resemble each other, and differ only in the greater sever- 
 ity of the one I have just described. In all essential features of the 
 eruption they are exactly alike. Now there is not room for the slightest 
 doubt as to the cause of the eruption in the second case. It was pro- 
 duced by the bromide of potassium, and it occurred in connection with 
 that drug twice to the same child. I may here remark that I know of 
 no difEerence between the eruption due to iodides and those due to 
 bromides. The same variety occurs, I think, in both, and the general 
 laws as to idiosyncrasy are the same. The iodide, however, depresses 
 the system far more than the bromide. The eruptions produced by 
 bromides are, I think, attended by less constitutional disturbance, even 
 when locally very severe, than are those due to iodides. A case well 
 illustrating this came under my notice a few weeks ago. I was asked 
 by a medical friend to see an infant in whose case the diagnosis had first 
 been varicella, and next smallpox. Complete isolation had been en- 
 forced, but as the eruption had steadily got worse, and the child now at 
 the end of a month remained perfectly well as to health, all had become 
 convinced that there was a mistake. I have mentioned the names 
 which had been given to the eruption as the best means of suggesting 
 the appearances it at first assumed, and I may add that the surgeon who 
 attended the case was an experienced and sagacious man. The infant, 
 when I saw it, was fat and smiling, but with its face and all four ex- 
 tremities absolutely covered with large' buttons of most formidable ap- 
 pearance. Many of them had scabs, but none of them had ulcerated 
 
42 THE PEDIGREE OF DISEASE. 
 
 much. At first I was told that the eruption was present before a medi- 
 cal man was consulted, and before any medicine had been given, but on 
 pressing for accurate dates, I found that my suspicion was correct, and 
 that the surgeon was first consulted for a slight feverish cold, for which 
 he prescribed small doses of bromide of potassium, and that the rash 
 did not begin to appear till three days later. No suspicion having been 
 entertained, the bromide had been continued until the day of my visit. 
 My friend told me that he was very fond of the bromide for children, 
 and had given it in thousands of cases, but had never before seen any 
 eruption produced. In looking back on the experience of former years, 
 I recollect several cases under my own care, and that of other surgeons, 
 in whom I think there i^ great reason to suspect that persistence in the 
 iodide caused death. They were cases in which an eruption which was 
 probably due to it alone was mistaken for a specific one, and the drug 
 pushed still further. In the report which I published in the Clinical 
 Society's ' Transactions ' I have published two cases in which our eyes 
 were opened only just in time. They were all cases in which the salt 
 had been continued for some weeks. It may be possible, however, for 
 fatal poisoning to occur in connection with the first few doses. In the 
 case of a man admitted into the London Hospital some years ago, only 
 two or three doses had been taken, and an eruption which looked like 
 haemorrhagic variola had been produced, together with such an amount 
 of swelling about the neck and throat that nothing but the prompt per- 
 formance of tracheotomy could have averted immediate death. The 
 facts respecting this case were published by my colleague Dr. Stephen 
 Mackenzie, and the same indefatigable observer has also placed upon 
 record the most extraordinary example of iodide poisoning with which I 
 am acquainted. In this instance, an infant, aged five months, died of 
 iodic purpura after a single dose of only two grains and a half. 
 
 The domain of idiosyncrasy in respect to Specific Fevers is exceed- 
 ingly important as regards both the physician and the surgeon, and I 
 shall make no attempt to distinguish arbitrarily between their interest 
 in this matter. That which the surgeon is familiar with in the case of 
 syphilis and those remote and exceptional sequelae of measles, scarlatina, 
 and smallpox which come under his care, may be used to throw light 
 upon the facts which fall under the observation of the physician in the 
 
IDIOSYNCRASY AS TO SPECIFIC FEVERS. 43 
 
 earlier stages of these latter maladies. There is probably no good reason 
 for believing that the specific animal poisons can vary in their intensity 
 beyond certain narrow limits. Different epidemics of scarlet fever and 
 small-pox do unquestionably vary somewhat, but after all, the limits of 
 deviation from average intensity observed in different epidemics are as 
 nothing compared with what we witness in different individuals attacked 
 in the same epidemic and apparently under like circumstances. In the 
 latter case we see constantly that it is possible for two individuals in- 
 fected from the same source and with the same virus to show the one 
 an eruption consisting only of a few spots almost unattended by fever, 
 whilst the other develops a confluent or even haemorrhagic exanthem, 
 which will prove fatal in a few days. Is it possible to give any explana- 
 tion of these individual differences, except by attributing them to indi- 
 vidual peculiarities, and when these peculiarities arise to an extreme 
 height, can we name them more conveniently than as idiosyncrasies? 
 I will endeavor to illustrate the subject by facts which have come under 
 my own personal cognizance. The portraits which I produce exhibit a 
 gangrenous and ulcerative eruption which occurs in connection with 
 varicella. They are, in fact, a peculiar form of varicella in which the 
 eruption tends to persist and the individual vesicles ulcerate or become 
 gangrenous. The evidence upon which I venture this unqualified 
 assertion is, I think, conclusive, for this eruption has been observed 
 repeatedly with the history that in the first instance it was supposed to 
 be chicken-pox, and whilst chicken-pox was in the family; and in a few 
 yet more definite cases, the surgeon who identified the gangrenous case 
 was the witness at the same time of varicella in its ordinary mild form 
 in the patient's brothers and sisters. The facts have fallen under the 
 observation not of myself alone, but of many others, and they receive 
 important incidental corroboration from several narratives published 
 long ago, and without full perception of the interpretation of the facts. 
 My present object is to cite them simply in proof of the possible in- 
 fluence of idiosyncrasy in modifying the course of an exanthem. The 
 case to which the portrait which I next show belongs, was that of an 
 infant to all appearance in perfect health, who had several brothers and 
 sisters, all healthy, who had all been vaccinated at the usual time with 
 the usual results. In this child, however, vaccination was followed on 
 
44 THE PBDIGKEE OF DISEASE. 
 
 the seventh day by a general eruption on the skin, which on the tenth 
 day looked like ordinary small-pox, which subsequently became gan- 
 grenous, and caused death at the end of a fortnight. The state of the 
 child's skin at the time of its death is well shown in the portraits." 
 It will be seen to be covered, by spots and patches of gangrene, the 
 sphacelus involving the whole thickness of the skin. There is no form 
 of variola known which in the least resembles this condition, and none 
 will suggest, I think, that diagnosis. On the other hand, there is a 
 well-known eruption, usually slight and mild but occasionally very def- 
 inite, which occurs after vaccination, to which the term vaccinia exan- 
 them is appropriate. My suggestion is that this eruption bears the 
 same relation to the ordinary mild vaccinia rash which gangrenous vari- 
 cella does to the common type of chicken-pox, and that its exceptional 
 severity was due to individual idiosyncrasy. 
 
 I show next another portrait from a similar case which was observed 
 by Mr. William Stokes in Dublin, to whose kindness I am indebted for 
 the portrait. The general facts were similar to those in my own case, 
 with the difference that the eruption occurred a day or two earlier after 
 vaccination, that the patches of gangrene were more irregular and more 
 superficial, and that the child survived. I do not know that any other 
 examples of gangrenous vaccinia have as yet been published, but I have 
 no doubt that such will in the future be observed. I have now related 
 some extreme instances illustrating the influence of idiosyncrasy in caus- 
 ing severity of exanthems which are usually very mild. Probably there 
 are quite as striking examples of the converse, instances in which the 
 specific animal poisons pass through the system and produce little or 
 no obvious effect. It may be that these are much more common, and 
 that they go far to explain some of the great apparent irregularities in 
 the course of the exanthemata. We often meet with individuals who 
 tell us, for instance, that they have never had scarlet fever or measles, 
 although they were exposed in childhood at the same time that their 
 brothers and sisters suffered; and we often see these diseases go through 
 a family and leave one or more children apparently untouched. Still 
 oftener will it happen that one or several individuals under such cir- 
 
 ' One of these is copied to illustrate my paper on this subject in this year's 
 volume of the " Medico-Chirurgical Transactions." 
 
IDIOSYNCKASY AS TO SCARLET FEVEK. 45 
 
 cumstances will show only a very slight febrile ailment, without any 
 of the more characteristic symptoms of the disease, whilst others suffer 
 severely. 
 
 It has happened to me recently to witness a family epidemic of scar- 
 latina which remarkably illustrates what I wish to say. In mentioning 
 its details, let it not be supposed that I think that it illustrates any- 
 thing unusual; on the contrary, I believe that similar occurrences fall 
 very frequently within the experience of those engaged in general 
 practice. 
 
 My facts are briefly these: a child was affected with sore-throat and 
 feverishness, but had no rash whatever, and beyond a slight fur, no 
 change in the condition of the tongue.. She was well in a day or two, 
 and nothing subsequently occurred to her. Four days later another 
 child sickened with exactly similar symptoms, but more marked, and 
 in her the usual rash of scarlatina soon appeared; and subsequently a 
 little boy went through the same course of events. Both of these ob- 
 served precisely the same periods as regards the progress of the disease; 
 both had nose-bleeding on the same day, followed by rheumatism begin- 
 ning in the same joints, the wrists, and both had great swelling of the 
 cervical lymphatic glands.' Subsequently an older sister, who was be- 
 lieved to have had it some years ago, went through a rather sharp attack. 
 Thus, I take it, there can be no doubt that the disease, in this instance 
 was scarlet fever; but to prevent any question on the score of diagnosis 
 I may add that one of the patients was seen by Dr. Gee. 
 
 It is to what I have next to state that the chief interest attaches. 
 The child who was the first ill, and who had but a day's sore-throat, no 
 tongue affection, no rash, no peeling, was subsequently most fully ex- 
 posed to the risk of infection, and did not take it, conclusively proving, 
 I think, that the trivial illness she experienced was the fully developed 
 malady so far as her idiosyncrasy permitted it to show itself. But I 
 have other facts yet more curious. Almost, the whole family, and it 
 was a large one, suffered one after the other, during the two or three . 
 weeks that the disease was in the house, from sore-throats and a day or 
 two of feverishness. Several of them had never had scarlet fever be- 
 fore, but as to some others, it was doubtful. In all, the cervical lym- 
 phatics swelled more or less, but in no instance was there the slightest 
 
4G THE PEDIGREE OF DISEASE. 
 
 peeling or any sort of sequela. I have yet to add that, when the first 
 child had sore-throat, I was at once told that the family of a cottager, 
 living at a short distance from the house had Just been suffering from 
 similar throats. This cottager iVas the milkman, and there had also 
 been personal communication between the two houses. On inquiring 
 at this cottage, I found that the father, mother, and two grown-up 
 daughters had all in succession had sore throats, attended for a day or 
 two with rather sharp febrile illness, but in no single instance had any 
 rash been observed, nor had any peeling of the skin followed. They 
 were not known to have had scarlet fever on any former occasion, and 
 laughed at the suggestion that what they had now had was it. It may 
 be that after all it was not, but the dates fitted well with the possibility 
 that the first of the children affected had got the contagion from this 
 source. The inference which I wish to draw from such narratives as 
 this is, that it is possible for the individual peculiarity of patients — a 
 peculiarity which may be hereditary and may affect many individuals 
 in the same family — to so far modify and minify the course of an exan- 
 thematic fever as to make its recognition quite impossible, and that we 
 ought to seek for the explanation of these remarkable differences, 
 amounting in many instances to almost total suppression, not in varia- 
 bleness in the degree of epidemic virulence, nor in the hygienic sur- 
 roundings, nor in anything which can properly be called the state of 
 health of the patient, but in that of which we can give no other expla- 
 nation than that it must rank as an idiosyncrasy. 
 
 It is needless to point out what a pitfall of fallacy is here opened for 
 the feet of the investigator. How easily may we find ourselves attribu- 
 ting to influences which were wholly inoperative, results which must 
 simply be put aside as those which we ought to have expected under the 
 known laws of idiosyncrasy. I will leave for the present the examina- 
 tion of those laws as they influence the course of a certain other speci- 
 fic fever. This is the time at which I ought properly to mention the 
 facts which, in the case of the protracted fever known as syphilis, illus- 
 trate its extreme inequality of incidence in different persons. I must 
 not, however, enter into any details now, and I leave them aside the 
 more willingly because the facts to which I refer are matters of univer- 
 sal knowledge. We all know how differently chancres behave in differ- 
 
IDIOSYNCRASY AS TO .SPECIFIC FEVERS. 47 
 
 ent persons; how they may become phagedsenic or sloughing without 
 our being able to assign any cause for the pecuiiarity. We know, also, 
 that the syphilitic rash in many cases is wholly omitted, together with 
 the rest of the train of secondary phenomena. "We know also how,, 
 when secondary symptoms do appear, how infinitely variable they may 
 be in form and in severity. A roseola, a, lichen, a psoriasis, a rupia, 
 an eruption indistinguishable from variola — such are a few of the forms 
 which we frequently sek Impressed by these startling differences, 
 good observers have tried to make out that there are different kinds 
 of virus, but all the facts are in opposition to such hypotheses. I must 
 content myself by suggesting that they are due to inherent differences 
 in the individuals who receive the virus, and must now pass on to other 
 topics. 
 
 Let me nest remark that, not only is the sphere of individual pecu- 
 liarity almost unbounded in its power of modifying the force of the 
 primary outbreak of an exanthem, but that it exercises a great influence 
 in determining who shall and who shall not, suffer from complications 
 and sequelae. Under this latter term I am alluding rather to what may 
 be called accidental sequelae; the inflammations of various organs and 
 parts which occur exceptionally and at some little distance of time, and 
 which often bring the patient under the care of the surgeon. The 
 peeUng of the skin, and possibly also the nephritic desquamation which 
 follows scarlatina, are sometimes classed as sequelae, but are really parts 
 of the primary disease. As I think my narrative has conclusively 
 shown, peeling of the skin is not a sequel of scarlet fever per se, but of 
 one of the symptoms of scarlet fever, namely, of dermatitis; to which 
 it is always proportional, and of which it is the necessary consequence. 
 Inflammations of the ears, and of the bones or joints, stand, however, 
 in a different category, and so does the ophthalmia tarsi, which often 
 follows measles, and the pruriginous affections of the skin which are 
 not infrequent after both vaccinia and varicella. When these events 
 happen, they occur probably not by any means as necessary parts of 
 the disease, but ^rather as revealing idiosyncrasy in the individual. 
 Inflammations of the ear and allied affections may possibly in some in- 
 stances reveal diathesis rather than idiosyncrasy. That is, it may be 
 that they occur because the patient is distinctly scrofulous, or the sub- 
 
48 THE PEDIGREE OF DISEASE. 
 
 ject of some other form of recognized ill-health. Even as regards 
 them, however, I much doubt whether this is always true, and respect- 
 ing the affections of the skin to which I have referred, I am sure that 
 they often occur to those who are in good health, and that they are 
 proof of idiosyncrasy only. 
 
 Differences in the degree of irritability of the skin are common, and 
 may proceed to great length. Flea-bites, woollen clothing, nettle- 
 stings^ and the like, produce on different persons extremely different 
 results. Urticaria is a form of dermatitis of which probably but few 
 persons are susceptible, and in those in whom it occurs it demonstrates 
 or reveals this susceptibility and nothing more. The patient who gets 
 nettle-rash whenever he eats lobster may yet be able to digest lobster 
 with as little inconvenience as other people. It is his skin, or perhaps 
 the nerves of his skin, in which the susceptibility alone lies. In this 
 suggestion rests, so far as I can see, the real explanation of the mala- 
 dies which have been grouped together under the name of Prurigo: 
 There is no one disease to which that name is applicable. "What we 
 witness is the power of various causes of local irritation' to provoke pru- 
 riginous dermatitis in those in whom idiosyncratic susceptibility exists. 
 Now it is the presence of pediculi which is the starting-point; in other 
 cases of fleas; in yet others the occurrence of an exanthem, such as 
 varicella; whilst in all, the morbid condition, once initiated, is kept up 
 by the patient's unwise efforts to relieve it, and by the mere fact of its. 
 having got possession. I repeat, there is no such disease as " Prurigo," 
 a malady which has been described by a high authority as if it were 
 self- existent;, and alike causeless and cureless; but there are plenty of 
 persons born with that peculiar irritability of skin in which a variety 
 of causes may evoke the symptoms to which that name has been given. 
 
 "We may probably, with much confidence, place diphtheria and ery- 
 sipelas side by side as diseases, — or rather type forms of the inflamma- 
 tory process, — which obey parallel laws. Probably no human being is 
 exempt from the liability to them, but at the same time it seems cer- 
 tain that the degree of proneness varies very much in different individ- 
 uals, is persistent through life, prevails in families, and is matter of in- 
 heritance. Thus, then, we assert for both the existence not unf requently 
 of a sort of constitutional predisposition to which the term diathesis, or 
 
IDIOSYNCRASY AS TO ERYSIPELAS, ETC. 49 
 
 even in some instances, that of idiosyncrasy, is applicable. Both may 
 become contagious, and of both exposure to direct contagion is probably 
 by far the most efficient mode of production. Many persons will take 
 them by contagion in whom other causes would have proved abortive. 
 But both are capable of spontaneous origin or, to speak more correctly, 
 may be produced by exposure to certain non-specific influences, such as 
 the ordinary causes of catarrh, injuries, sewer gas, and some others. It 
 is most important that all who value accurate classification should deny 
 both as regards erysipelas and diphtheria their right to rank with those 
 fevers which are due to specific animal poisons. With these, as it seems 
 to me, neither of them has any real affinities. In both, I repeat, that 
 with which we have to deal is a pergonal and inherited peculiarity, giv ■ 
 ing proclivity when certain exciting causes are brought to bear, to pecu- 
 liar forms of inflammatory action. In both the disease is probably 
 local at its origin; in both it spreads locally by the contagion of con- 
 tinuity of tissue, and in both constitutional symptoms result which are 
 in some ratio with the extent and severity of the local action. E"either 
 of them in the least protects the individual from future attacks; indeed, 
 and although in each single attacks are common enough, yet dt is gen- 
 erally acknowledged that those who have suffered once are more prone 
 than others to suffer again, and in both there are not infrequent in- 
 stances of proclivity lasting through many years. 
 
 In erysipelas the essential feature is a spreading inflammation of lym- 
 phatic spaces in the skin producing great oedema, and usually great en- 
 largeraent of blood-vessels. In diphtheria we have a spreading inflam- 
 mation of a mucous membrane, attended by oedema, dilatation of 
 blood-vessels, and the formation, in greater or less quantity, of a fibrin- 
 ous pellicle. Although I mention skin as the seat of the one and 
 mucous membrane of the other, let it be distinctly understood that 
 these are only the most usual sites; both may attack cellular tissue or 
 wounds, and each may occasionally affect the usual territory of the 
 other. 
 
 There may be some doubt as to how, when these inflammations affect 
 
 repeatedly the same individual, the fact should be explained. It may 
 
 • be that one attack leaves a really increased proclivity to a second, or it 
 
 may be that the first simply revealed a proclivity which had existed all 
 4 
 
50 THE PEDIGREE OF DISEASE. 
 
 along, and of which the later ones are merely the manifestations with- 
 out addition. Probably both explanations are true. 
 
 It is, I presume, not necessary that I should produce before this 
 audience any citation of evidence in proof that a personal liability to 
 erysipelas and diphtheria may be witnessed. All are familiar with 
 them. It is proba,ble that there are some slightly marked affinities with 
 the diseases just named and such maladies as carbuncle, boils, and acne. 
 Respecting all these we have the same questions to ask, how far are 
 they dependent upon constitutional causes? and, how far upon those 
 which are local ? We may take it as certain that in all there is a double 
 causation, and our task is to assign in each instance the relative share 
 of each. In the first place we may say that the liability to acne, to 
 boils, to carbuncles, is often a family matter, and is seen to occur with 
 unusual frequency in relatives. It is often also a personal matter, as is 
 proved by its persistence or recurrence at various periods of life. 
 Further, the association of these maladies with more or less temporary 
 disturbances of health, with diabetic dyspepsia, with constipation and 
 defective tone, is a matter of constant observation. 
 
 Whoever has reflected, however, as to the real nature of carbuncular 
 inflammation, will, I think, see reason to believe that its peculiarities are 
 to a large extent local ones. Eespecting both boils and carbuncles, it 
 is the fact that the most efficient measures of treatment are those which 
 appeal to the local condition. This is true of all the different measures 
 in repute, however dissimilar at first sight they may appear. Some 
 have for their object the protection of the inflamed area from further 
 irritation, as when we cover up a boil or commencing carbuncle with 
 leather plaster, others the subdual of the inflammation by means of cold 
 and the like, as when we use an ice-bladder or a strong spirit lotion. 
 N"or do those who adopt a time-honored practice of an early free incision 
 depart from this principle, for their object is stUl the mitigation of local 
 inflammation by the relief of tension, and by permitting the escape of 
 contaminating matters. From acne, impetigo, and ecthyma to boils is 
 in many cases a matter of degree, and that there is little or no real dis- 
 tinction between a large boil and a small carbuncle, all will, I think, 
 admit. The age of the patient, and his special diathetic condition at 
 the time, their site, the influence of different modes of local treatment. 
 
IDIOSYNCRASY IN REFERENCE TO CARBUNCLE, ETC. 51 
 
 are the conditions which determine the final result. If a boil occur in 
 an elderly person, on the nape of the neck, where it is likely to be irri- 
 tated by the shirt-collar, and especially if j instead of being systematically 
 protected from the first, it be further bullied by premature squeezing 
 and the like, it is very likely to pass on into a carbuncle. I claim the 
 strong testimony which has been borne by Sir James Paget and others 
 to the efl&ciency of simply protective measures in preventing the devel- 
 ,, opment of small carbuncles, and obviating the supposed necessity for 
 incision, as proof that local spreading is, in the main, due to local 
 causes, and has no necessary connection with the general health. In 
 other words, it is not a thing which is inevitable. On the other hand, 
 we know of no internal remedy which possesses any marked power in 
 arresting carbuncular inflammation 
 
 If now we ask. In what does the peculiarity of carbuncular inflamma- 
 tion consist ? in what does a carbuncle difEer from a boil ? I should be 
 inclined to reply that it is solely in this tendency to spread. The spread- 
 ing is effected by contagion of continuity, and it has certain marked 
 resemblances to what we observe in erysipelas. A carbuncle might 
 almost be defined to be an erysipelatous boil with the proviso that the 
 expression is not intended to imply identity of inflammatory type, but 
 only close similarity. Throughout its whole course, and however ex- 
 tensive it may be, a carbuncle, in combination with its erysipelatous 
 method of spreading, contains the characteristics of the furuncular 
 process. Its secretions and its core, or slough, are exactly like those 
 of a boil, excepting that they are much more abundant. In a general 
 way there appears to be a natural tendency, independently of treatment, 
 to the arrest of the process, and this is not generally observed in erysipe- 
 las. In other words, erysipelatous inflammation is more intensely infec- 
 tive than is carbuncular. I must, however, qualify even this admission 
 of difference by reminding you, that carbuncular inflammation has 
 such an injurious influence on health, that in all cases in which its 
 spread continues in spite of treatment the patient quickly dies. Thus 
 many cases occur in which no proof is given of tendency to arrest. It 
 may easily be the fact that in some states of system, and some types of 
 carbuncle, there is as little tendency to arrest as there is in phlegmo- 
 nous erysipelas. 
 
52 THE PEDIGREE OF DISEASE. 
 
 I fear I have wandered rather far from the subject of diathesis, but 
 my argument, if I have succeeded in making it clear, is this; that there 
 exists a certain state of tissue and constitution, different in each in- 
 stance, which gives proclivity to diphtheria, to erysipelas, to acne, to 
 boils, and to carbuncle, and that while the importance, the almost 
 paramount importance in many instances, of local influences- in excit- 
 ing and. aggravating is kept in mind, the diathesis in the background 
 must not be forgotten. Further I have argued that carbuncle is the 
 result of a sort of combination of the erysipelatous and furuncular types 
 of inflammation. I feel sure that these views as to pathology will be 
 found to fit well with therapeutics. 
 
 Tetanus is a malady so rare, that if we admit its possible spontaneous 
 production without regard to previously existing proclivity, we must 
 not expect to find many instances in proof that the latter does sometimes 
 exist. Yet there are such, and possibly if looked for more than we 
 might suppose. The influence of race is proved by the great liability 
 both of infants and adults amongst the negroes, and also of certain 
 animals. I have met with a few cases in English practice which ap- 
 peared to imply that there might be an inherited proclivity to tetanus. 
 A man who looked quite well walked into my room as an out patient 
 at the Metropolitan Free Hospital and gave me his own diagnosis by 
 declaring " I am going to have lockjaw." I found that he had recently 
 had a slight wound on one hand, and that he was beginning to feel 
 some stiffness of his jaws. His symptoms, however, were exceedingly 
 slight, and his anxiety was caused by the fact that his father had died 
 of tetanus. The poor fellow's foreboding was rapidly realized, and he 
 died within a week. 
 
 Here, for the present, Mr. President, I must take leave of the subject 
 of idiosyncrasy. I have endeavored to claim for these forms of indi- 
 vidual peculiarity a much wider sphere of influence than is usually ac- 
 corded to them. It is necessary, I am well aware, that one should 
 exercise some scepticism in accepting doctrines of the kind which I have 
 brought before you. To fall back on the suggestion of an idiosyncrasy 
 is so easy that it may easily become the resort of intellectual sloth. We 
 must not, however, be deterred by this consideration from the acceptance 
 of such doctrines if they are true. That they are so within certain 
 
IMPORTANCE OF RECOGNITION OF IDIOSYNCRASIES. 53 
 
 limits I cannot doubt, and the problem before us is to find those limits. 
 If we fail to recognize, or if we forget, the influences of idiosyncrasy, 
 we shall not only waste much time in our processes of clinical research, 
 but we shall be in constant danger of coming to wrong conclusions by 
 declining to accept evidence as to cause which is really sound, and 
 of adopting false principles in reference to treatment. In every ex- 
 ample of a curious and unexpected form of disease, our minds should, 
 I think, first ask the question, " How much of this may possibly be due 
 to the individual peculiarities of its subject?" We are often on a 
 wrong track if we seek to make external influences explain the whole. 
 Let me add, in conclusion, and it seems to me of great practical 
 moment, that the individual peculiarities of all patients should be care- 
 fully studied, and that they should themselves be made intelligently ac- 
 quainted with them. There are few of us without our idiosyncrasies, 
 and their variety is innumerable. If it should become the custom for 
 parents to record some sort of life-history of their children in permanent 
 form from the birth or infancy onwards, noting all the peculiarities in 
 an individual by the aid of medical observation, not only would much 
 be done in the way of preventing subsequent errors in the treatment of 
 disease, but valuable contributions would be made to our knowledge of 
 its real nature. It is not only as regards the prescription of our drugs 
 that a knowledge of our patient's peculiarities becomes important to 
 use in practice. The advice we have to give in respect to places of res- 
 idence, mode of life, and of general management are often of far 
 more importance than the medicine prescribed. Its wisdom or the 
 reverse may depend on our knowledge or ignorance of the individual 
 peculiarities, and those peculiarities frequently do not display themselves 
 in any of the existing symptoms, but can be recognized and revealed only 
 by a correctly kept life-history. 
 
LECTURE IT. 
 
 Me. Presidekt and Gentlemen, — "We turn to-day to a new depart- 
 ment of our subject. I have been dealing hitherto with fixed inborn 
 peculiarities which are for the most part beyond our explanation, but 
 in consequence of which disease in individuals nlay assume very peculiar 
 features. How peculiar and exceptional those features may be I have 
 illustrated by the production of cases of bullous, pruriginous, and even 
 gangrenous varicella, and of two examples of gangrenous vaccinia. 
 I have also reminded you of the great difEerences in different individuals 
 in the type and severity of syphilis, and I have shown, too, how, not 
 only may the exanthemata sometimes attain most unusual severity, but 
 that not unfrequently all their usual symptoms may seem to be sup- 
 pressed and the patient may pass through a complete attack scarcely 
 knowing that he has been ill. We have further glanced at the facts 
 which prove that the iodides and bromides, remedies in daily and most 
 frequent use, and for the most part very harmless, may occasionally 
 act as violent poisons. Lastly, I have urged that in many other mor- 
 bid processes originating in connection with ordinary and known 
 causes, or it may be from local infection, the peculiar constitution of 
 the individual takes an important share as well in increasing the pro- 
 clivity as in modifying the result. Instances of this I found in such 
 diseases as diphtheria, erysipelas, and carbuncle. Eespecting these and 
 the other examples of personal proclivity or immunity which I have 
 ventured to cite, I have maintained the same argument, that they are 
 all independent of everything that is to be recognized in the state of 
 hep,lth of the patient, and that they imply that which is conveniently 
 known as idiosyncrasy. Much, indeed almost all, that I have advanced 
 is, I am well aware, by no means novel. I have been dealing with old 
 names and well-established doctrines, and my reason for bringing them 
 before you has been, not so much the hope of being able to contribute 
 
 new facts or theories of my own, as the desire to set in better order 
 
 54 
 
ON DIATHESIS. 55 
 
 that floating knowledge whicli is a general possession. In the lectures 
 which are yet to come I shall restrict myself to the same design. I am 
 going to ask your attention to a great number of topics, to many of 
 which I shall advert with such brevity that it would not be possible 
 for me to enforce original views even if I possessed them. The bond of 
 connection which will associate these various subjects will be the en- 
 deavor to discover whether there exist any large groups of states of 
 personal peculiarity giving special proclivity to diseases which can be 
 suitably defined and named. If the reply to this question be in the 
 afiirmative — if we see reason for believing that those who become our 
 patients do really difEer one from another in respect to definite tend- 
 encies, which are of prolonged duration and upon the knowledge of 
 which we can conveniently base not only our prognosis but our treatment, 
 it will next be our duty to examine as to the real nature of those states 
 and the laws under which they came into being and continue to exist. 
 I have dismissed the consideration of temperaments as being when 
 correctly limited an unproductive field of research, but in doing this I 
 expressed a belief that the investigation of the diatheses stood in a very 
 different position. In the one we deal with the peculiarities of race and 
 the results of what may be termed breeding, in the latter we begin 
 much nearer home and investigate the consequences of a variety of 
 influences which are capable either separately or together of producing 
 chronic disease. For, in fact, what we mean by a diathesis is little 
 other than an exceedingly chronic disease. It is a disease or taint 
 which lasts a lifetime, which may be active at times, and latent at 'times, 
 and which may.be handed on to another generation. If we accept as a 
 definition of diathesis that it is any condition of prolonged 'peculiarity 
 of health giving proclivity to definite forms of disease, we must admit at 
 once that it will comprise groups of maladies which are very different in 
 their nature. Of some of these states the causes are very definite and 
 specific, whilst of others they are much the reverse. Of those which 
 are most definite, such as leprosy and syphilis, it may perhaps almost be 
 doubted whether there is any. convenience in calling them diatheses at 
 all. In certain stages when the disease is active there is assuredly no 
 object in using any other word than the substantive name. It is chiefly 
 when external symptoms are absent for a time in the individual, or when 
 
56 THE PEDIGREE OF DISEASE. 
 
 we witness the phenomena of hereditary transmission that we feel to 
 need the addition of such a word as diathesis. It is in most conditions 
 easy to say of an individual " he has got syphilis," or "he has not got 
 syphilis," or "he is the subject of leprosy; " for the dise^/Se in each in- 
 stance is a definite one, and there is no such thing as a state of physical 
 proclivity to either. Such maladies, however prolonged may be their 
 possible duration, stand in the very different category to scrofula, 
 rheumatism, or catarrh. These latter are diatheses which may vary 
 within the widest limits in the individual, and are so common as to be 
 well-nigh universal. "We can scarcely assert of any one that he is free 
 from them, and the question is rather as to estimation of the degree. 
 They are diatheses in the truest sense of the word, and they belong to 
 the whole human family, and possibly, indeed, to all vertebrate ani- 
 mals. The mofe important questions to be put in reference to them 
 are not, have you got rheumatism, scrofula, catarrh, etc.? but rather, 
 in what degree are you catarrhal, rheuma.tic, or scrofulous ? The degree 
 of susceptibility in each varies exceedingly in different persons, and in 
 many instances rises to such a height that it constitutes a very serious 
 disease. To these, so to speak, universal diatheses I shall have to recur 
 in my last lecture. 
 
 In the same sense that we seek to know respecting our patients 
 whether they possess more than usual proclivities to rheumatism and 
 the like, we also inquire respecting various other states. Has he been 
 injured by malaria ? Has he been exposed to the causes which pro- 
 duce bronchocele? Has he a tendency to cancer? Is he gouty? 
 Has he any permanent peculiarity of the circulation giving tendency 
 to local disease, or of his blood-vessels causing risk of haemorrhage ? 
 In these and various other directions we see our way to the construction 
 of a host of diatheses of less importance than those we have mentioned 
 only because they are less common. In the present lecture I shall glance 
 at certain general groups of diatheses, arranged according to their 
 causes, and in the two subsequent ones I shall take various special 
 diseases, or isolated symptoms, and examine in respect to each how far it 
 is possible to make use of it as a clue to the diathetic state producing it. 
 Our knowledge of many of the diatheses is for the present far too vague 
 to admit of our attempting any satisfactory classification of them, and a 
 
DIATHESES DUE TO CLIMATE. 57 
 
 further difiBculty occurs in the fact that their differences are often very 
 dissimilar in kind. We might suggest a group of those which are 
 transitory and those which are permanent, and others of those which 
 may be acquired, and those which are solely obtained by transmission. 
 It is clear, however, that any such grouping as this would often ne- 
 cessitate our placing the same malady in more than one class. On the 
 whole, I think the simplest plan will be to make for the present a rough 
 classification of the causes of diatheses, a task far easier than that of the 
 diatheses themselves, and following this, I shall bring before you a few 
 examples of each. 
 
 I will commence first with diatheses in relation to climate. Under 
 the term malaria we may include all the various emanations from 
 marshy grounds, swamps, and jungles. As to its exact nature we know 
 nothing, but that, whilst similar in essential qualities, it varies in dif- 
 ferent localities, both in intensity and character, seems certain. Its 
 effects upon the human constitution may be to produce quickly very 
 severe disease, but, whether acute or otherwise, attacks of arterial spasm 
 attended by visceral congestions are almost constant phenomena. Its 
 effects, whether exposure be continued or otherwise, are always perma- 
 nent. The man who has once had ague will display through life pecu- 
 liar susceptibilities. Under all circumstances likely to cause shivering 
 he will show especial tendency to rigor. He will shiver if a catheter be 
 passed, or if he be exposed to cold, or if inflammation is initiated; and 
 it becomes a matter of some practical importance to the operating sur- 
 geon to remember that rigors occurring to such patients are not so 
 serious in their import as in others. They are retrospective symptoms, 
 and reveal the fact that those to whom they occur have at some former 
 period come under the influence of malaria. One attack of malarial 
 fever by no means prevents another, and although subsequent attacks 
 are usually less severe than the first, yet the effects of the poison are 
 distinctly cumulative, and. the limits within which acclimatization can 
 secure immunity are probably much more narrow than has been sup- 
 posed. It is easy to see that a poison which can be so persistent in its 
 action and of which the effects, even in mild cases, are so well nigh 
 permanent, must be capable of producing that state of body which we 
 name diathesis. The malarial diathesis is, indeed, a well-marked one. 
 
58 , THE PEDIGREE OF DISEASE. 
 
 and it exists in greater or less degree in all who have ever come under 
 the influence of its cause. It is probably in some degree hereditary, the 
 inheritance being, we may suppose, in ratio with the severity and length 
 of duration of the disease in the parent. Inasmuch as the offspring of 
 those who have suffered are usually born under conditions of continued 
 exposure to its cause, it is difiScult in them to discriminate between 
 what is inherited and what is acquired. So great, however, is the Com- 
 bined influence of the two that a fearful state of physical degradation 
 may be thus produced, and in this the inhabitants of a whole district 
 may be involved. Nor is the physical health alone affected; the ner- 
 vous system is especially involved, and the mental and moral faculties 
 are largely influenced. When we remember how permanent in heredi- 
 tary transmission such influences become, we can easily understand that 
 the malarial diathesis has, in many instances, had a large share in con- 
 trolling the destiny of a nation or damaging the character of a race. 
 This diathesis can easily mix itself with any other, and in London prac- 
 tice we encounter it very frequently in association with that of syphilis, 
 and occasionally both with it and that of alcoholism. I am speaking, 
 of course, not of London residents, but of those who have lived abroad. 
 A climatic diathesis which must be placed side by side with that due 
 to malaria is the one which results in bronchocele and cretinism. Here, 
 again, we are ignorant of the precise cause, but we know that it apper- 
 tains to certain local telluric conditions, and especially to mountains and 
 valleys, just as we know of ague that it belongs to marshes. The cause 
 of this diathesis is much more slow in its effects than is malaria. Far 
 longer residence: in the locality is required, and for its worst effects it 
 appears to be essential that there shall have been transmission through 
 several generations. It appears to persist with considerable tenacity in 
 families which have once suffered from it. Like malaria, it degrades 
 the entire man, and whenever prevalent produces certain deterioration 
 of race. This diathesis may perhaps be most conveniently named, from 
 its most conspicuous symptom, the bronchocele diathesis. It is ab- 
 surd in the case of this endemic disease to speak of bronchocele only, 
 since the general health is always at the same time involved. -At the 
 risk of being accused of repetition, I must here again insist upon the 
 features of distinction between diathesis due to food and those to be as- 
 
FOOD DIATHESES. 59 
 
 signed to climate. The latter are distinctly restricted and endemicj the 
 others not so. The latter, when seyere, affect all immigrants who come 
 within their range of influence, without regard to health, position, or 
 habits, and under certain circumstances leave scarcely any exempt. 
 The diet-diatheses, on the contrary, as illustrated by leprosy and the 
 like, affect immigrants only very seldom, and with great apparent capri- 
 ciousness, taking one and leaving a thousand untouched. 
 
 These diet-diatheses constitute a group of great importance. They 
 are persistent constitutional conditions — sometimes hereditary, at others 
 not so — which have their origin in connection with food. Of them by 
 far the most important for us, as English surgeons, is gout. Perhaps 
 I ought to have assigned the foremost place to scrofula, and I should, 
 indeed, have done so, but that it probably acknowledges a mixed causa- 
 tion. In many gouty patients the sum total of the diathesis is, as 
 regards its causes, mixed. There may be susceptibility to weather, and 
 to influences on the nervous system, as well as to articles of food, but 
 these we can separate from what we mean by gout itself; and so far as 
 this is concerned, I believe we must all acknowledge that it is a question 
 of diet. About the intermediate steps of causation there may be room 
 for much discussion and difference of opinion. But I suspect that no 
 one will decline to accept the suggestion that had mankind continued 
 to be vegetable-feeders, and never known the use of wine or beer, we 
 should have had no experience of gout. If this be granted it is all I 
 ask, for it is to be freely admitted — nay, expressly asserted — that such 
 a thing as uncomplicated diet-gout is now scarcely to be met with. If, 
 however, we can succeed in any degree in separating its complications 
 from itself, we shall find in gout the best type from which to study -the 
 laws of a diet diathesis. In my own mind, leprosy stands next to gout 
 in the certainty that it is due to food, but I cannot speak as to this 
 theory of its origin as being yet commonly admitted. 
 
 Certain general statements may be expected to be found true concern- 
 ing all diatheses which are due to food. They ought to be the same or 
 nearly the same, in all countries where the same diet is used, and they 
 ought to cease where the diet is wholly changed, and to undergo modifi- 
 cation, or to become rare, when it is modified. To some extent they 
 ought to be curable by abstention from the articles of food supposed to 
 
60 THE PEDIGREE OF DISEASE. 
 
 be their cause; but we must not push this too far, since many constitu- 
 tional conditions, when once established, may persist, or even become 
 hereditary, after the removal of their true cause. I scarcely need re- 
 capitulate the facts respecting gout which prove its association with 
 dietetic habits. They are too well known. It may be well, however, 
 that we should be reminded that the diathesis, when once established, 
 becomes by inheritance remarkably persistent, and that it is unques- 
 tionably the parent, when so transmitted, of many very peculiar mala- 
 dies of which the affiliation might easily have been overlooked. I went 
 into some detail in one of a former series of Lectures in describing a 
 peculiar form of destructive inflammation of the eyeball — a chronic and 
 almost painless irido-cyclitis^ — which occurs only in those who inherit 
 gout, and I shall not now say more respecting this disease than that I 
 have, since my former lecttire, seen some remarkable cases which sup- 
 ported the views then propounded, and none at all which were ex- 
 ceptional to them. There are several other less definite, and still less 
 common forms of eye disease which stand, I believe, in the same re- 
 lation to gout, and with them I would ask to be permitted to place 
 (and I speak not without the justification of carefully-collected evidence) 
 a large number of cases of crippling rheumatism, almost all those which 
 are known as spondylitis deformans, a gi-eat majority of the cases of 
 gonorrhojal rheumatism, most of the severe forms of neuralgia occur- 
 ring to young persons, and many peculiar liabilities to haemorrhage. It 
 seems, indeed, under the ordinary customs of English society, very diffi- 
 cult, even after several generations of strict temperance, to get rid of 
 the gouty diathesis, and some facts would dispose us to the belief that, 
 even after it has ceased, perhaps, during several generations, to mani- 
 fest itself in the typical form of joint disease, its effects may still be en- 
 countered in predisposing to disease of blood-vessels, of the kidney, and 
 of the nervous system. , 
 
 The facts regarding leprosy are probably somewhat different, but 
 some allowance must perhaps be made for the circumstance that we 
 have not as yet had an opportunity of examining them so critically. It 
 would appear to be far easier to produce leprosy de novo than it is to 
 produce gout, and it appears also, as might be expected from this fact, 
 to die out of the system and out of. the race much more quickly than 
 
FOOD DIATHESES. 61 
 
 does gout Probably it is associated with some much more definitely 
 specialized dietetic poison than that which causes gout. For, if the 
 hypothesis which I advocated before you two years ago, and in which I 
 believe with increasing firmness, be correct, it is certain that the leprous 
 poison is capable of considerable concentration under favorable circum- 
 stances, and may produce its effects in a comparatively short space of 
 time. Many cases might be cited in which children or adults of healthy 
 English families residing for a few years in a leprosy district, and eating 
 only the ordinary food of the place, have become its subjects. Even in 
 these, however, the malady is never rapidly developed. It always comes 
 on slowly, and not unfrequently does not reach its height until possibly 
 several years have elapsed after removal from the place where it was ac- 
 quired and return to English food. This development of leprosy with- 
 out possibility of hereditary transmission, and after short periods of 
 residence in dangerous localities, is, I believe, never witnessed in tem- 
 perate regions, and never excepting where it is well known that un- 
 wholesome varieties of fish are met with, and where also the wholesome 
 kinds are liable to rapid decomposition. The fish theory assumes that, 
 under such conditions, the special leprous poison may be taken in very 
 eflBcient quantities in connection with a very small allowance of fish. It 
 is the quality of the fish, and not its quantity, that we must regard. 
 Nert I stop to note that the same fact is observed, though not to the 
 same extent, in the case of the beverages which produce gout. I am 
 especially anxious to draw attention to this statement, because it is 
 almost always forgotten or ignored by those writers who still disbelieve 
 in the fish hypothesis. 
 
 As regards my suggestion that the leprous diathesis is not only more 
 easily produced than that of gout, but dies out more quickly when the 
 cause is removed, many interesting facts might be mentioned. Almost 
 all authorities on the disease have laid stress upon its hereditary tenden- 
 cies, but a great fallacy underlies all their observations in that these 
 supposed tendencies have been witnessed in districts where the original 
 cause — supposing that cause to have been a poison taken in connection 
 with fish — was still in existence. Thus, it is easily possible that the in- 
 herited tendency may have been, at any rate, recruited from time to 
 time by the original poison. The careful observations of Norwegian 
 
62 THE PEDIGREE OF DISEASE. 
 
 physicians in the United States have proved that leprosy does not persist 
 in the families of immigrants from the leprous districts of their native 
 land, and have further, I think, made it probable — although I do not 
 know of any special cases that have been published in proof — that even 
 the subjects themselves of leprosy get well after a long residence in their 
 adopted country. I had the pleasure of producing before you, at the 
 time of the lecture to which I have referred, an old lady who had, under 
 my own observation during a period of about twenty years, recovered 
 from leprosy. She had contracted the disease in Barbadoes, and had 
 recovered in England. She is still alive and in good health, and has 
 now had no sign of leprosy for many years. This was the first case of 
 definite recovery from a severe and characteristic form with which, at 
 the time of my lecture, I was acquainted. Since then, however, two 
 other examples of recovery from leprosy — or, at any rate, a cessation of 
 all leprous processes — have come under my observation. The subject 
 of one of these, a distinguished missionary, now an old man, is blind 
 and crippled in all his extremities in consequence of leprosy contracted 
 in Jamaica thirty years ago. He has lived the greater part of this time 
 in Canada, and for many years has been quite free from leprosy mani- 
 festations. I did not myself see him when the disease was extant, but 
 the conditions which it has left justify the diagnosis, even if it had not 
 been placed beyond all doubt by the fact that it was made by Dr. Brown- 
 Sequard. Probably there are a great many persons living who are ex- 
 amples of the entire cessation of leprosy processes after long periods of 
 residence in healthy districts; but no particular interest appears as yet 
 to have been attracted to the search for them, and as the process of re- 
 covery is one which extends over such a long period of time, it is not 
 always easy to recover data which place the original diagnosis beyond 
 doubt. 
 
 Before leaving the subject of leprosy I must briefly summarize the 
 evidence anew which leads me to place it very confidently amongst the 
 diet-diatheses. It is the same in all countries, and probably has been 
 so in all ages. It is the same in rich and poor, in hot climates, and in 
 cold climates. It is certainly neither infectious nor contagious; yet it 
 is capable of origination in those who go to reside where it is rife. It 
 slowly gets well in those who leave its haunts and reside elsewhere. 
 
SCKOFTJLA. 63 
 
 It is not possible to mention any climatic condition which is common to 
 all the Tery varied localities where leprosy is found. Whenever it 
 occurs in a temperate climate it happens to those who are engaged in 
 the fishing trade, and who live, to a very large extent upon the poorer 
 kinds of fish. Although when it occurs in hot climates it usually ob- 
 serves the same rule, yet it now and then happens to those who eat but 
 little fish. But this is always under circumstances where fish is known 
 to be bad, and where it rapidly decomposes. Finally, in all temperate 
 climates leprosy disappears before advancing civilization, the introduc- 
 tion of agriculture, and the increase of population. 
 
 Before we can decide as to whether Scrofula should rank as in the 
 main a diathesis which is due to defective food, we have to ask what is 
 meant by the term. In answering this question, I am glad to acknowl- 
 edge help from the valuable lecture on this subject delivered before us 
 last summer by my colleague Mr. Travers. The general tendency of 
 modern investigation would seem to be to associate tuberculosis with 
 scrofula, and to teach that both may be, and usually are, the conse- 
 quences of inflammatory action in predisposed individuals. Much that 
 is known as scrofulous probably never reaches a distinctly tuberculous 
 condition. But the name is still, I submit, appropriately applied if the 
 inflammatory action can be shown to be of that type which often or 
 usually results in the development of tubercle. On the other hand, 
 there are certain cases in which the proclivity to tuberculosis is so strong 
 that it does not wait for the advent of an inflammatory exciting cause, 
 but is produced, as a lymphatic neoplasm, without the occurrence of 
 preceding congestion. In, however, the very large majority of tuber- 
 culous and scrofulous cases, a predisposing cause and an exciting cause 
 are both present; the former being an inherited proclivity, the latter an 
 injury, a catarrh, or any influence likely to produce local congestion. 
 
 The greater the degi-ee of hereditary proclivity the less is the need for 
 the exciting cause. We may note also that we frequently have to wit- 
 ness in the case of scrofula the influence of what may be called contribu- 
 tory causes, such, for instance, as the occurrence of an exanthem or 
 other acute illness. We have then to examine as to what may be the 
 influences under which a proclivity to inflammations of the scrofulous 
 type may arise, and we shall probably be not much mistaken if we make 
 
64 THE PEDIGREE OF DISEASE. 
 
 answer as we should do in the case of rickets, that they are largely due to 
 deficient and unsuitable food; but that, at the same time, it must be ad- 
 mitted that climate, clothing, and weather take each a very considerable 
 share. As, regards diet, it is probably a deficiency of fatty matters, such 
 as butter, oil, and the various other forms of animal and vegetable fat, 
 which is influential; and, as regards climate, deficiency of sun and expos- 
 ure to damp and cold. Scrofula, as we see it, is probably always inherited, 
 but it is often probably largely increased by exposure to the causes hinted 
 at. Possibly there are few practicable dietetic changes which would be 
 more beneficial to our English population, in reference to scrofula, than 
 a large increase in the consumption of butter and other animal fats. The 
 comparative immunity of those who use the fish oils as articles of food, 
 and the prophylactic virtues of cod-liver oil amongst ourselves, are, I 
 believe, established facts, and their lesson is of considerable importance 
 in reference to the dietetic causes of scrofula. We are enabled at the 
 present time to speak much more definitely as to the diseases which 
 should be classed as scrofulous, and as to their essential connection with 
 the tendency to tuberculosis, than we were some years ago. A con- 
 siderable number of diseases of the skin, of the bones, of the eye, have 
 been conclusively removed from the scrofulous group, and placed under 
 their proper designations, as cryptogamic in some cases, and syphilitic in 
 others. So far has this gone that I can easily imagine that there may be 
 some who think that I have given too wide a definition of scrofula, when 
 I asserted that it is not always associated with the growth of tubercle. 
 To such critics I will produce the instance of scrofulous ophthalmia, 
 which usually consists of a chronic, slow-to-heal ulceration of the cornea, 
 unquestionably dependent upon a constitutional cause, and often coin- 
 cident with other scrofulous manifestations. There are also diseases I 
 cannot but believe, amongst the inflammations of joints, which are slow, 
 comparatively painless, in the ordinary sense of the word " scrofulous " 
 and occurring in the relatives of those who are themselves tuberculous 
 but in which yet it is impossible to prove the presence of tubercle either 
 in the bone or synovial membrane. The frequent and comparatively 
 easy, and often permanent cure of many forms of scrofulous inflamma- 
 tion, is also, I think, another reason for believing that, although tuber- 
 cle is its ordinary goal, it is by no means always reached. The serofu- 
 
RACHITIS. 66 
 
 lous diathesis is indeed very ill-defined, and, in many instances, shades off 
 very gradually into other states of defective organization. How closely, 
 for instance, are many conditions which are called scrofulous associated 
 with those peculiar states of feeble circulation and irritable tissues 
 which give liability to chilblains, swollen lips, and the like affections ? 
 Yet these latter are not probably in any strong degree indicative of 
 tendency to tuberculosis. 
 
 The liability to Rickets, in other words to a derangement of health, 
 of which defective ossification is the chief, but by no means the only 
 result, should unquestionably rank as a diathesis. It is one, however, 
 which is usuaUy, though not quite invariably, terminable at a certain 
 period of life. In very rare instances, so rare as to be almost doubtful, 
 it may begin during intra-uterine life, but usually its advent is delayed 
 until near the end of lactation, and it reaches its climax, and begins to 
 subside just at the time when the child, hitherto carefully restricted 
 to a very few articles of food, and mainly to milk, is allowed to indulge 
 its tastes, and to have variety. With such facts the first suspicion must 
 certainly be that it is probably dependent on a milk regimen, and in the 
 main no doubt this suspicion is correct. In numberless instances it has 
 been proved that the milk upon which children have become " rickety" 
 was distinctly poor in quality. The advantages in change of regimen 
 are almost always well-marked, and although some experiments on the 
 lower animals have failed in the artificial production of rickets through 
 restricted food, others appear to have succeeded. Whilst, however, we 
 may safely believe that defects in diet are the main cause of rickets, and 
 that they may be effectual in the almost entire absence of others, yet it 
 is probable that others are usually present and contributory. In the dis- 
 cussion on rickets which took place at the Pathological Society two years 
 ago several speakers drew attention to the fact that the disease is very 
 rare in sunny climates, although infantile inanition from poor food 
 may be common. Mr. Spencer Watson in particular used arguments 
 which made it very probable that free exposure to sunlight and warmth 
 would do much' to enable a child improperly fed to yet effect assimila- 
 tion in such a way as to keep clear of rickets. We may certainly believe 
 it probable that our climate and the narrow sunless streets of our large 
 
 towns take their share in the production of what was once known on the 
 5 
 
66 THE PEDIGBEE OF DISEASE. 
 
 Continentas " the English disease." Let me here repudiate emphatically 
 the suggestioa which has recently come from Paris, that inherited 
 syphilis is the real cause of rickets. The two diatheses are probably 
 quite distinct, although they may often co-exist, and in other instances 
 may simulate each other. Inherited syphilis, — as the labors of Taylor in 
 New York, M. Parrot in Paris, aTid Drs. Barlow and Lees amongsb our- 
 selves, have shown us, — may frequently produce swellings about the 
 epiphyses, and a state of general tenderness of the skull due to ostitis, 
 which might be mistaken for rickets. 
 
 A word or two must here be said respecting a disease of the osseous 
 system of great rarity which has been named " Rickets of the Adult." 
 I allude to osteo-malakia, or Mollities ossium. It is probable that mala- 
 dies having relation to different causes have been confused together under 
 this title. But respecting a certain number of the best-marked cases, 
 there appears good reason to believe that the disease is really a form of 
 rickets, and that the differences observed between the two maladies are 
 chiefly due to the very different condition of the osseous system as 
 regards its development at the time of attack. Trousseau has recorded 
 a case in which osteo-malakia attacked a woman of seventy who had 
 been rickety in childhood, and another case in which this disease was 
 cured rapidly by the use of cod-liver oil and liberal diet. There is a 
 skeleton in the Brighton Museum which was obtained through the zeal 
 of that accomplished physician the late Dr. Ormerod, which is one of 
 the best examples of osteo-malakia that I have ever seen. The man 
 had had innumerable fractures, and partly through faulty union and 
 partly through bending of his bones, had lost more than two feet of his 
 stature. In this instance the man's children were much deformed by 
 infantile rickets. Although as an ordinary thing the diathesis of rickets, 
 if not fatal, passes away as age advances, and under the influence of 
 judicious dietetic treatment, we may reasonably suspect that there are 
 a few cases in which it does not do so, and that it is quite possible for it 
 to be reproduced or even initiated in adult life. In respect to its rapid 
 subsidence, and usually its complete disappearance when the diet is im- 
 proved, the rachitic diathesis has a close parallel in Scurvy. The latter 
 malady is indeed of such short duration that we might hesitate to applv 
 the term diathesis to it. It is for the most part an acute diathetic dis- 
 
SPECIFIC FEVERS CANNOT CAUSE DIATHESIS. 67 
 
 ease produced quickly and quickly cured. In saying this, however, we 
 have not said all, for there are cases in which scurvy passes into the 
 chronic form and becomes the source of permanent ill-health. When it 
 does so it may fairly claim to rank with the diatheses, and it is quite pos- 
 sible that, in exceptional instances, some degree of influence from it may 
 be hereditarily transmissible. In scrofula, rickets, and in scurvy, we have 
 examples of diatheses produced by defective food, whilst in leprosy and 
 gout we illustrate those due to some excess, or rather to something del- 
 eterious contained in the food. Close by the side of leprosy I ought to 
 discuss ergotism, pellagra, chronic lead-poisoning, and some others, but 
 time does permit. Can the specific animal poisons become the pro- 
 ducers of permanent diatheses? This question must, I think, be 
 answered in the main in the negative. Unquestionably they may pro- 
 duce conditions of ill-health which persist for a certain time, and may 
 cause various morbid manifestations; but these states are short-lived, 
 and perhaps are more fitly ranked as dyscrasisB than diatheses. This 
 is true even, I think, of syphilis, the most chronic and most persisting 
 of all specific fevers. Excepting in some very small degree of reduced 
 liability to the influence of the same poison which is to be observed in 
 the offspring of those who have suffered, I doubt whether in any case 
 the influence of a specific fever in a parent is to be traced in the off- 
 spring. No state of health which is heritable is ever produced. Some 
 few exceptions to this should perhaps be allowed when smallpox, measles, 
 and the like appear to intensify the diathesis of scrofula, but they are 
 probably of but little importance. The general law certainly is, that a 
 specific animal poison may breed in the blood, and may for the time pro- 
 duce most violent disturbance of the health of the individual, but its ef- 
 fects cease after awhile, and cease completely, and leave the body unmodi- 
 fied with the exception that it is no longer liable to the influence of the 
 same poison. This immunity lasts only during the lifetime of the individ- 
 ual, and cannot be transmitted excepting in an exceedingly slight degree. 
 Even in the individual it is by no means complete or invariable. I am 
 aware that there is an apparent exception to all this in the case of 
 syphiHs. I will speak of that directly, and will also say a few words as 
 to the limitation of the law of immunity of the individual. Before we 
 pass to those topics, however, it may be well to ask attention to the. 
 
68 THE PEDIGREE OE DISEASE. 
 
 strongly-marked differences which are to be observed between the states 
 of health produced by the specific poisons, and those which are due to 
 inflammation from non-specific causes and which come under the law 
 of intensification by habit. In the development of such inflammations 
 as those of erysipelas, diphtheria, elephantiasis, and especially when not 
 due to contagion, the constitution of the individual takes a large share, 
 and the mere fact of their occurrence reveals his previous proclivity. 
 The disease originates, in part from without, but in part also from with- 
 in. It is not an instance of intrusion, but of development, and pe- 
 culiarities of blood, tissue, or nervous system, are exactly those which 
 are capable of increase, fn the case of the exanthems, however, the 
 body of the sufferer is in the main passive, and is acted upon by a poison 
 which is intruded from without, and to which nolens volens his tissues 
 must submit. The occurrence of the exanthem reveals nothing and in- 
 tensifies nothing. It is from first to last a violence done from without, 
 by an external agent, and when its direct effects are over, the body may 
 be supposed to return in all other respects to its original state. A man 
 who has been put in the stocks is not especially likely to acquire the 
 habit of going to sit there, nor does the man who has been burned, or 
 who has broken his leg, acquire therefrom any tissue-proclivities. His 
 tissues were in no sense consenting parties, and the laws of habit do not 
 come into play. The possibility of second attacks, and the absence of 
 protection to offspring, are facts which indicate that the influence of 
 exanthems is only transitory. As regards the immunity of the in- 
 dividual, conferred by an attack of an examthem, we may assume that 
 it is neither complete nor universal. Modified attacks may occur re- 
 peatedly in the same person, nor are second and fully-developed ones 
 unknown. Thus it is, I believe, a matter of general creed in the pro- 
 fession that, when scarlet fever is in a house, those who have gone 
 through it before are liable to suffer from sore-throat without the rash : 
 and that with measles catarrh may in the same way denote a minor 
 degree of protection. The modification of variola by vaccination, and 
 also the limited duration of immunity, are well known facts. Second 
 attacks even of variola itself may occur. 
 
 Eemembering the length of time during which the effects of the 
 ,-yphilitic fever may persist, we might perhaps expect that it would 
 
SPECIFIC FEVERS CANNOT CAUSE DIATHESIS. G9 
 
 prove more constantly protective than the others. But the facts teach 
 us that we must not conjecture, but be content to observe. No one has, 
 I believe, ever categorically denied the possibility of second attacks of 
 syphilis, but the opinion which almost universally jjrevailed, a few years 
 ago, came very near to this conclusion. That, however, second infec- 
 tions with modified results are tolerably common, and second attacks 
 with full development of all the phenomena, not extremely rare, is, I 
 feel sure, the truth. I have recently had under my care, at one time, 
 three patients in whom it was certain that they were passing through 
 second attacks. In more than one instance the patient has been under 
 my own observation during both attacks. One of those which I have 
 just referred to is a very remarkable case, on account of severity of both 
 attacks. The patient, now a surgeon, of about forty-five years of age, 
 had syphilis when a student. It was attended by a free rash, and was 
 followed by various sequelae, which he did not get rid of for three years. 
 Then he married, and he now has healthy children. In the beginning 
 of the present year he obtained by some accidental inoculation a 
 chancre on the lip. It became very large, much indurated, and was 
 attended by large glandular swellings. Subsequently a most copious 
 eruption followed, and aoth in primary and secondary phenomena, the 
 case was as severe a one as I have seen for a long time, It may be that 
 idiosyncrasy has something to do with this exceptional recurrence of 
 liability during the individual's lifetime. In one instance, — in which 
 I attended a member of our own profession twice for syphilis, first when 
 a student, and secondly, ten years later, — the same person had, he 
 assured mc, twice had variola. In respect to vaccination, it is, I believe, 
 well recognized that some persons lose its protective power much sooner 
 than others. Those who, by an attack of an exanthem remain protected 
 through life, may be said in some sort to have acquired a diathesis. It 
 is one, however, which, as I have already asserted, does not manifest 
 itself by any active phenomena, nor is it one the influence of which 
 extends to offspring; or if it does so, it is to an extent so small as to be 
 almost inappreciable. It is a remarkable but undoubted fact, that 
 quoad the specific fevers the offspring of protected parents starts afresh. 
 It may be, and probably is, the fact that in successive generations the 
 tissues become to some extent habituated, and sufEer less severely, but 
 
70 THE PEDIGREE OF DISEASE. 
 
 still they do sufEer, and nothing approaching to immunity is ever ob- 
 served. 
 
 I have been speaking of the non-inheritance of the negative diathesis 
 induced by an attack of any one of the specific fevers, but it remains yet 
 to say a few words as to my assertion that none of them produce an active 
 diathesis which is heritable. The only exception to this which will be 
 alleged is syphilis. I shall be asked " Is not the diathesis of syphilis 
 often transmitted from parent to offspring ? " Probably it is not the 
 diathesis which results from the disease, but the germs of the disease 
 itself — the particulate elements of the virus — which are transmitted. 
 It is transference, a form of contagion rather than hereditary trans- 
 mission, which occurs. Two years ago I produced before you, at 
 some length, the facts which point to this conclusion. Since then, by 
 further thought on the subject and the accumulation of more evidence, 
 my opinions on this subject have been much strengthened. "We well 
 know that the danger of transmission to children has reference not to 
 the state of health of the parents, but to the lapse of time which has 
 occurred since the primary disease. We see cases in plenty in which 
 parents whose children have been quite healthy, subsequently afford 
 conclusive proof that the diathesis still persists in themselves. Indeed, 
 it is almost an acknowledged law that parents in the late tertiary stages 
 do not transmit taint. On the contrary, when offspring are born in the 
 secondary stage of the disease, especially in its early periods, it is a rule, 
 with exceedingly few exceptions, that the disease is transferred. These 
 facts strongly favor the belief, that the inheritance of syphilis so-called, 
 is possible only while the fluids of the parent contain the living elements 
 of the virus. These elements, in a large majority of cases, develop 
 and go through the same stages as if inoculation had occurred at the 
 time of birth. It is far more like contamination in utero than true 
 inheritance. By contamination in this use of the word I mean that with 
 sperm or germ (of either or of both parents), there passes the virus 
 itself, the sperm or germ being itself unmodified, but simply the material 
 medium of transference. In the case of the mother we know well that 
 it is not necessary that the germ should have been infected at all but 
 that if her blood receive the virus, even so late as the eighth month it 
 will pass into that of the child also. Inherited syphilis, when produced 
 
LAWS OF INHEEITANCE OF SYPHILIS. 71 
 
 under these last-mentioned circumstances, runs exactly the same course 
 as^when derived from a parental taint which existed before conception. 
 A child then, I assert, inherits syphilis in precisely the same sense, and 
 in precisely the same manner, as it may inherit smallpox. It inherits 
 not the diathesis, but the disease. The reason why the inheritance of 
 smallpox is very rare, whilst that of syphilis is unfortunately common, 
 is simply that the period during which the virus is extant in the blood 
 is very different in the two cases.' The conspicuous facts, then, with 
 which we are all so familiar in reference to the syphilis of infants, afford 
 no proof that the diathesis of syphilis, any more than those of the other 
 exanthemata, is capable of transmission. It remains, however, for us 
 to inquire whether there are other facts, of a somewhat different kind, 
 which support the view which I have endeavored to combat. I am 
 alluding, of course, to the old controversy as to whether some forms 
 of struma, and especially such diseases as lupus, may not be modified 
 forms of inherited syphilis. My own belief is very strong indeed to the 
 effect that they are not, but the facts are very detailed and very difficult 
 to marshal concisely. My argument, if- I have made it plain, has 
 pointed to the conclusion that no minified transmission of syphilis is 
 possible, that the child gets either nothing at all or the germs of the 
 disease, and that in the latter ca,se they will, subject to the laws of 
 idiosyncrasy, develop equally in all- cases. 
 
 Let me try briefly to state some facts on this question, and I will then 
 leave it to your judgment. N"othing is more common than for parents 
 who have themselves at some former time suffered from sjrphilis, to 
 produce children who remain through life robust and in perfect health. 
 Sometimes one or more of the family inherit syphilis, and suffer, it 
 may be, severely, whilst others, usually younger ones, escape, and when 
 this occurs the latter may enjoy almost exceptional vigor. When I 
 have seen a whole family of grown up children, the offspring of syphilitic 
 parents, manifesting signs of cachexia, there has usually been reason to 
 think either that all had actually suffered from the full disease, or that 
 the symptoms present in some were not specific, but due to other causes. 
 I have seen very numerous cases of lupus on the one hand, and of in- 
 herited syphilis in young persons on the other, but I have never found 
 the two things together, nor have I ever recognized in the subject of true 
 
72 THE PEDIGREE OF DISEASE. 
 
 lupus tlie brother or sister of one whom I knew to have suffered from in- ' 
 herited syphilis. Of the cases of lupus which I have seen, in a very great 
 number there were strong reasons for denying the probability of syphilis 
 in the parents. I have, of course, occasionally seen inherited syphilis 
 and scrofula together in the same patient, but a large majority of those 
 who suffer from the former never show any tendency whatever to the 
 latter. In what I have said above I have been speaking of course of 
 common lupus, and have wholly excluded that form of destructive 
 ulceration which is sometimes mistaken for lupus, but which is from 
 beginning to end syphilitic, and is curable by specific treatment. I have 
 taken lupus as being a type form of disease, but what I have attested, 
 as regards it, applies equally to other forms of scrofula, to psoriasis, and 
 other diseases, which have been suspected as the remote consequences 
 of specific taint. I believe that the domain of inherited syphilis is just 
 as definite and just as restricted as that of the acquired disease, and that 
 it stands sponsor to none but its own progeny. 
 
LEOTTJEE V. 
 
 Mk. Pkesident and Gentlemen, — In reference to malignant new- 
 growths it is possible to use the word diathesis as applicable to two 
 different things. We may mean a state of tissue-health giving pro- 
 clivity to cancer, or the state which results from the existence of cancer. 
 I will ask permission to employ the word cancer in its old and popular 
 sense, as including malignant new growths of all kinds. This is the 
 sense in which it has been used for centuries, and it is, I think, a pity 
 that it should be changed, especially as we have in carcinoma, as op- 
 posed to sarcoma, a very convenient term by which to distinguish for 
 scientific purposes certain forms of malignant new growths from others. 
 In examining as to diathesis, we must merge all the distinctions which 
 have been established by the splendid labors of modern histologists, and 
 speak of malignant new growths as one family. Indeed, it is by no 
 means improbable that some forms of new growth not counted as malig- 
 nant, ought in this matter to bei placed with those which are so, and that 
 we should estimate the individual tendency to new growth in general 
 without paying too much regard to differences of kind. We not infre- 
 quently observe that some persons display more than one form, and 
 when hereditary transmission occurs it is very common to see it produce 
 a growth of a kind different from the original. On this doctrine of 
 transmutation in transmission I had much to say in my last year's 
 lectures. 
 
 The term diathesis is, I think, to be repudiated, as not suitable in 
 
 reference to liability to the general diffusion, local recurrence, and 
 
 failure of health which the existence of cancerous growth produces. 
 
 These are all the direct and immediate effects of the disease, part of 
 
 it, a ad are better named the cancerous dyscrasia. The real question 
 
 before us is whether there exists any peculiar state of health wholly 
 
 antecedent to the development of any local growth which gives proclivity 
 
 to it. If such exists, and especially if it be in any way recognizable, 
 73 
 
74 THE PEDIGEEE OF DISEASE. 
 
 -the term diathesis may be conveniently applied to it. The first obser- 
 vation to be made in reply to this question is that cancer in the main 
 is obviously dependent upon age, that it is in nine cases out of ten part 
 of senility — a sort of second childhood of the tissues. Amongst the 
 lovrer animals yet more than with ourselves, cancers are, I believe, 
 almost always the appanage of age. Old dogs and old cats get cancer of 
 the lip or mamma, but these maladies are scarcely ever seen in young 
 animals. When new growths which approach the malignant type are 
 met with in the young there is probably almost always a history of in- 
 heritance. If we admit this statement we admit, at the same time, 
 that there is a cancerous diathesis; since it is clear that a state of health 
 may be transmitted which gives proclivity to the disease, without actual 
 conveyance of the cell germs of the new growth. The probability that 
 such states of tissue-health exist, is increased when we take cognizance 
 of the numerous cases in which, with strong hereditary history, no 
 manifestation occurs until adult or even senile periods of life are 
 reached, though it must be admitted that these facts may be held to 
 be evidence in both directions. "We shall probably be not far from the 
 truth if we admit senility of tissues, local or general, to be the one pre- 
 disposing cause of cancer with which we are acquainted; whilst injuries 
 and all forms of local irritation are its exciting causes. A little step 
 further may next be taken, in the belief that everything which tends to 
 hasten senility, either local or general, will increase the predisposing in- 
 fluence, and in this category may be placed anxiety, distress, over-work, 
 and excesses of all kinds. It is highly probable that under such condi- 
 tions a state involving increased proneness to cancer' may be induced, 
 and further, that if offspring are produced after that state has been de- 
 veloped, they will inherit that tendency. This leads me. to say a few 
 words as to the last-suggested cause of diathesis which I have placed 
 in my list. It may ha,ve seemed strange to some that it should have 
 been even hinted that senile changes can ever produce anything worthy 
 of that name. It was by no means my intention to propose to re- 
 christen old age by the name diathesis. What had occurred to me was 
 rather this: Are there not conditions of tendency to premature old age 
 which amount almost to disease and which are sometimes observed to 
 run in families? The results are simply general tissue-degenerations. 
 
ALL INFLAMMATION INFECTIVE. ^0 
 
 — atrophies^ arcus senilis, white hair, pale blood, and general failure of 
 nutrition- — and yet the causes are to be sought among the ordinary causes 
 of disease. Both arcus senilis and white hair, when met with, as they 
 sometimes are, early in life in many members of the same family, and 
 wholly without other accompanying signs of senility, may be held to 
 rank as idiosyncrasies of tissue, and imply little or nothing as regards 
 the future. But there are many cases in which they are attended by 
 other conditions, and in which they imply much. It is possible that 
 arcus senilis may be in the course of hereditary transmission sometimes 
 wholly detached from the state of health which produced it, and may 
 become, as we have suggested that haemophilia and xanthelasma some- 
 times are, heritable per se. More usually, however, it is probable that 
 other conditions, such as tendency to arterial disease, accompany it, and 
 that the total result is a state of premature senility. Certainly there 
 are families in which a tendency runs to early senility rather than to 
 any specific disease. I recently had occasion to amputate the lower 
 extremity for senile gangrene of the foot of a gentleman who was barely 
 fifty, but in whom general calcification of the arteries had proceeded to 
 an extreme degree. I cannot but think that it woiild be convenient to 
 recognize as a diathesis the state in which premature senility amounts 
 to a disease. 
 
 I wish next to ask attention to certain laws as to persistence, self- 
 aggravation, and recurrence, under which morbid processes, due in the 
 first instance to simple causes, or possibly quite accidental, may in the 
 end breed diathesis. The best examples of this, which I shall be able 
 to find, will perhaps be in such maladies as catarrh, erysipelas, and 
 elephantiasis. Indeed, in what I said as to carbuncle, diphtheria, and 
 erysipelas, I Ijave already glanced at it. In our last lecture I contended 
 that the specific fevers, in virtue of their own specificity, — and that they 
 are intrusions from without rather than modifications of existing ele- 
 ments and processes, — possess no power of originating pathological 
 habit, and thus do not become the parents of diatheses which are per- 
 manent. After a longer or shorter time their influence ends. In the 
 instance of syphilis the length of reign is undoubtedly prolonged; still 
 it does eventually terminate, and terminate completely. In my argu- 
 ment on this point I suggested that there was an essential difference in 
 
76 THE PEDIGREE OF DISEASE. 
 
 respect to this between inflammations which begin from particulate con- 
 tagia and those set up by other influences, inasmuch as the latter do 
 tend by the mere fact of existence to develop what we call pathological 
 habit, and to increase in power by the mere fact of possession. Itis, of 
 course, not meant that they always do so, for fortunately there are other 
 vital forces which are constantly working in other directions and tend- 
 ing to the restoration of health. What I wish to hint is that there is 
 always a risk that an inflammation once experienced may become more 
 or less habitual, and that its tendency is, if not counteracted, in that 
 direction. In some minor degree this is true probably of all inflamma- 
 tions, ^yen of those which have been caused by injuries. There are 
 several ways possible in which local inflammations or local injuries may 
 become the causes of permanent change in the general health. They 
 may in the first place, by the long-continued pain and irritation caused, 
 reduce the nerve tone, and thus stamp a lasting impression on the cere- 
 bro-spinal part of the organization; or secondly, by long persistence they 
 may influence alike the blood and the nervous system. Sometimes it is 
 not persistence so much as tendency to frequent recurrence which effects 
 a similar mischief. Lastly, I shall have to maintain a theory that all 
 inflammatory action is in itself infective, not to the same extent, but 
 after the same pattern as malignant new growths. On this latter point 
 permit me to go into a little detail before I proceed to the others. It 
 is, I am sure, a fact familiar to all surgeons that, when acute periostitis 
 attacks one bone, other bones are very prone to follow. Many years 
 ago this curious fact attracted the attention of Mr. Simon, who wrote 
 on it under the name of " necrosial fever." The affection of the other 
 bones is distinctly secondary to that of the one injured, and not simul- 
 taneous. There is usually a considerable interval; and further, those 
 bones which suffer latest never suffer so severely as the first. It is 
 exactly as if from the bone first inflamed some elements had been shed 
 into the blood having the power to infect others. The bones affected 
 secondarily may be in no structural connection with the one first at- 
 tacked — may, indeed, be at a great distance from it. . Thus, I have 
 seen it begin in the tibia and occur secondarily in the humerus, scapula, 
 and ulna. The risk of implication of other bones exists only during the 
 early stages of the disease, and is, I think, very seldom witnessed after 
 
INFECTIVE PROPERTIES OF INFLAMMATION. 77 
 
 the first fortnight. Mr. Simon's term, "necrosial fever," might per- 
 haps suggest similarity with the form of multiple acute arthritis which 
 we name rheumatic fever. In the latter, however, many joints are 
 affected simultaneously and symmetrically, and all suffer in equal sever- 
 ity. In these features rheumatic fever differs much from what I have 
 been just describing, and suggests that the different Joints are affected 
 independently of each other and from a cause common to them all. It 
 is quite possible, however, that even in rheumatic fever the law to which 
 I have adverted may be in force. We may remember that sometimes 
 the arthritis does for a short time restrict itself to a few joints, or even 
 to one, and that often some joints which escape at first suffer later on, 
 whilst the implication of the heart never happens until a considerable 
 time after the first outbreak in the joints. These facts would fit well 
 with the theory that the parts first inflamed contaminate the blood and 
 become the causes of inflammation of similar tissues elsewhere. It may 
 be that it differs chiefly from necrosial fever in that the process is much 
 more rapidly accomplished. At any rate as regards multiple periostitis 
 we may be sure that in it the multiplicity is not to be explained by suj. - 
 posing that there is from the beginning some common cause, since in 
 nine cases out of ten the inflammation of the bone first affected was 
 caused by an injury. All who 'have paid attention to the development 
 of eczema cases will, I am sure, bear out what I am now going to assert. 
 It is very common for eczema to begin locally, from a known local cause, 
 such as the use of an irritating lotion or poultice, the employment of 
 washing powders, or exposure to heat, and for the eruption subse- 
 quently to become general. It is possible that the restriction to the 
 part first affected may be very short, or, on the other hand, it may be 
 very long. I feel that I may almost venture to extend the scope of my 
 first assertions and to say that I believe that it is rare for a local eczema, 
 if allowed to persist, not to become sooner or later a general disease. It 
 would be easy to collect instances innumerable in which eczema begin- 
 ning around an ulcer on one leg has been followed by eczema on the 
 other quite independently of any ulceration. It is not extension by 
 continuity of tissue, or even by contiguity, but reproduction of the same 
 type of inflammatory action in the same tissue at a distant part. In 
 almost all cases of general eczema there is the history of an early period 
 
78 THE PEDIGREE OF DISEASE. 
 
 in which it was restricted to one part. I have several times seen diseases 
 of the finger-nails (chronic onychitis) appear on several fingers and on 
 both hands, apparently in consequence of an injury to one. In these 
 instances there is always, I think, a long interval between the injury 
 and the affection of the other fingers, and during the interval the injured 
 nail has always remained in a state of chronic inflammation. A gen- 
 tleman who had consulted me a few weeks ago for thickened and opaque 
 nails, and in whom several on both hands were in various degrees af- 
 fected, told me respecting one which in no respect differed from the 
 others: "Oh, that has been so for thirty years; it was from a crush." 
 I found that the crushed finger nail had been diseased for twenty years 
 before the others began to suffer. He had no skin disease, nor was there 
 any history of such in his family, but I must add that he believed that 
 his grandfather had had some affection of the finger nails. It will be 
 thought by many that this latter fact deprives the case of its supposed 
 significance and reduces it to simply an example of hereditary tendency. 
 I have no doubt that in most cases in which local inflammation shows a 
 power of contaminating the system we must acknowledge the existence 
 of a predisposing cause as well as the exciting one, and it is to this role 
 chiefly that I should incline to assign inheritance in the case just nar- 
 rated. No doubt the cases in which local eczema becomes general hap- 
 pen in persons who have a proclivity to eczema, but this fact only re- 
 duces and by no means takes away, the importance of the exciting cause, 
 since without it, in all probability, the morbid phenomena would never 
 have come into existence. The occurrence of eczema in any part and 
 in connection with any local cause, must rank as a revealing symptom 
 to this extent that it makes known the fact that its subject is one liable 
 to eczema; but itself must next, if what I have suggested be correct, 
 rank as a cause, and a very efficient cause, of aggravation of the pre- 
 viously existing proclivities. CTnder this suggested law of self-aggrava- 
 tion the permitted persistence of any local disease may become a source 
 of danger, just as we well know the permitted persistence of a malignant 
 growth constantly does. Nor surely is there any a priori reason why 
 the life tendencies of inflammatory products and of those of new growths 
 should be wholly dissimilar in this respect. Amongst other instances 
 of maladies which often begin singly and locally and subsequently be- 
 
PATHOLOGICAL HABIT. 79 
 
 come multiple or general, we have boils, sycosis, common lupus, various 
 scrofulous affections, and certain forms of rheumatism. Eespecting all 
 these I believe that it is true that if they are cured after having persisted 
 a long time, the patient remains far more liable than others to a fresh 
 development. In some sort a diathesis has been produced. In the case' 
 of periostitis I have seen some remarkable examples of this. 
 
 We have now to consider the laws just adverted to, in relation to those 
 which regulate the recurrence of inflammatory attacks. That certain 
 forms of erysipelas are prone to become persistently recurrent is, as I 
 have already observed, well known. We habitually recognize the fact 
 that some patients are "liable to erysipelas," and expect that in them 
 attacks will be produced by slight causes and that they will prove of 
 much less severity than first ones usually do. If the recurrence has 
 been very frequent the attacks are usually very short and mild; some- 
 times the intervals are so short that the disease becomes almost persist- 
 ent. Exactly the same facts are observed as regards proclivity to catarrh 
 in all its varieties. They are sometimes also seen in liability to re- 
 peated attacks of diphtheria, a fact which has been recognized by mai.y 
 writers. I had recently occasion to perform tracheotomy in an orphan 
 school on a child who was in extremis from croup. In conclusive proof 
 of the nature of the disease we removed at the time a large fibrinous cast 
 of the trachea. The child had passed through, I was informed, four 
 attacks of croup previously. It recovered after the operation, and has, 
 I believe, since been threatened with a sixth attack, which, however, 
 never became severe. There is a peculiar form of oedema of the eyelids 
 and cheeks which is caused by repeated attacks of erysipelatous inflam- 
 mation, and which results at last in permanent deformity. Of this I 
 have seen many examples. In these cases the first attack is usually one 
 of the ordinary form of erysipelas of the face, with the liability to indefi- 
 nite extension constantly witnessed in the malady; but the later ones 
 are limited, both in duration and extent, and the patient at length 
 comes to know what to expect, and to be confident that the swelling 
 will not go further than the face, nor last longer than a week or ten 
 days. In some persons, and especially, I think, in the young, the 
 upper lip and the alae nasi are affected rather than the eyelids. The 
 type of inflammatory action sometimes, as may be inferred from what I 
 
80 THE PEDIGREE OF DISEASE. 
 
 have said, ceases to be the most characteristic of erysipelas, and in others 
 from the beginning it has in minor features departed from that type. 
 Thus there is a form which we might call vesicating erythema which 
 often affects the cheeks symmetrically, is of limited duration, and occurs 
 over and over again. In some instances the vesication is extremely 
 slight, or possibly absent, and erythema with cedema is all that we see. 
 The cases differ from erysipelas in that there is little or no tendency to 
 spread at the edge, and in some instances, in the comparative absence 
 of cedema. They occur, I think, chiefly to the young, but adults and 
 elderly persons are liable to recurrent inflammatory attacks of parallel 
 clinical history in which the type of disease is rather that of an acute 
 but transitory eczema. All those diseases appear to be for the most 
 part catarrhal in origin, that is, the' exciting cause is usually exposure 
 to wind or cold. They are of great interest to us as proof that maladies 
 which are probably due to very similar causes both predisposing and ex- 
 citing may yet be attended by differing outward manifestations, and 
 that, when once the type has been taken in the individual, the recur- 
 rences will be all of the same character. They also form interesting 
 pathological links one with another, and between erysipelas and its allies. 
 The morbid conditions which I have been referring to certainly estab- 
 lish in the individual who is their subject, through their long persist- 
 ence or frequent recurrence, a state of health well deserving the name 
 of diathesis, and there can be little doubt that the peculiarity so pro- 
 duced might, and would be likely to, become hereditary. We thus have 
 occasion to note how a permanent and transmissible peculiarity of health 
 may take its origin. Erysipelas has in elephantiasis a congener of great 
 interest. The distinction between the solid cedema which results from 
 recurrent attacks of erysipelas and the more characteristic form of ele- 
 phantiasis is only a matter of degree, and it is well known as regards all 
 elephantiasis that repeated attacks of rigors with erysipelatous swelling 
 are constant features of the disease. One is tempted, indeed, to go the 
 whole length, and declare that elephantiasis is, after all, only an exam- 
 ple of persisting, or exceedingly chronic erysipelatous inflammation with 
 its resulting hypertrophic changes. Elephantiasis may vary infinitely 
 in degree, but not at all, so far as I know it, in kind. It always begins 
 in cedema, and from this it slowly progresses to hypertrophy. The 
 
BEATI POSSIDENTES. 81 
 
 hypertrophy may implicate the corium and cellular tissue only (" smooth 
 elephantiasis"), or it may involve also the papillse, and produce the 
 tubercular form. Usually these two forms occur together in different 
 parts of the same limb. The^solid oedema, which is its first stage, may 
 begin from a variety of causes. It may be induced by an attack of bond 
 fide erysipelas, by an injury, by any slight local inflammation, a chan- 
 cre, an excoriation between the toes, etc., etc. Almost invariably its 
 persistence is favored by the mechanical disabilities of the part, as re- 
 gards the return of the venous blood and the contents of the lymphat- 
 ics. We meet with elephantiasis chiefly in the legs, the labia, clito- 
 ris, penis, and scrotum, parts which, if once they become swollen, are 
 dependent. The non-symmetry which prevails in a large majority of 
 cases denotes the influence which purely local inflammation has in locat- 
 ing the disease. In some cases it affects equally both legs, and in these 
 it may be taken for granted that the constitutional predisposing cause 
 is strong. Such cases prove the fact of hereditary diathesis. They are 
 scarcely ever met with in England, but only in those climates where the 
 disease is endemic, and in races or tribes which are peculiarly liable to 
 it. "When the elephantoid process has once well set in I believe it is 
 never wholly cured; and no better instance could be produced of the 
 pathological advantages of possession. The worse the disease is, the 
 worse it is likely to become. It is emphatically a self -aggravating mal- 
 ady. The mere fact of its existence tends necessarily to its spread. 
 Slowly but surely it undermines the health of its subject, impoverishr 
 ing his blood, and mainly by the recurring attacks of erysipelas which 
 attend it, enfeebling his tone. Constitutional treatment does but little, 
 and local measures are the only chance of beneflt. 
 
 We need not feel much difficulty in interpreting the phenomena which 
 we witness both in recurring erysipelas and persistent elephantiasis. 
 They are doubtless examples of the pathological power of habit and 
 indulgence. Just as a man who has yielded to intemperance is in dan- 
 ger of becoming a drunkard^ so it is with the tissues. The oftener they 
 have yielded to any special process of inflammation, the more prone are 
 they to yield again. No doubt but that, as in the case of the drunkard 
 and the epileptic, so also here, pre-existing susceptibility takes its share 
 
 in favoring both the first outbreak and the continuance. This share, 
 6 
 
82 THE PEDIGREE OF DISEASE. 
 
 however, probably varies mucb in different cases, and may in some have 
 been but very small. The main power at work has doubtless been the 
 increase of proclivity which every recurring attack begets, until at length 
 the habit or the disease, call it which we will, becomes fixed. Nor 
 must we consider, as I have already remarked, that this power of habit 
 will be restricted in its influence to the individual. If children be borne 
 to a man after the habit has been acquired, they will almost necessarily 
 inherit it. The certainty of inheritance will be in ratio with the fixity 
 of the habit and the length of time that it has persisted before the birth 
 of offspring. A great difference must be noted as to the inheritance of 
 proclivities which are developed before and after the conception of off- 
 spring. If a disease comes into active existence only subsequently to 
 the production of the whole of the offspring of its subject, clearly the 
 latter will inherit only the degree of proclivity,— and it may chance to 
 have been but very small, — which their parent may have originally pos- 
 sessed; but if born after the diseased process has been loijg in activity, 
 they will take over the original disease much augmented under the force 
 of pathological habit. Illustrations of this in the case of the children 
 of drunkards are of common occurrence. It is all the difference that 
 there is between one who simply bequeaths his patrimony as he received 
 it, and one who has largely increased it by his own gains. Elephantia- 
 sis, although precisely the same disease, whether met with in temperate 
 climates or in the tropics, is far more common and severe in dark races 
 and in hot countries. Malaria has, perhaps, something to do in pre- 
 disposing to it, and heat and moisture iinquestionably aggravate it. It is 
 possible, however, that we have much exaggerated our impressions both 
 as to race and climate as strong influences, since the laws of inheritance 
 will account for excessive prevalence to a large extent when once it has 
 obtained its hold. It may be that we should regard it as to a considerable 
 extent resulting from a diathesis which is heritable in certain families, 
 tribes, and races. 
 
 There are certain phenomena which may, perhaps, deserve the name 
 of Revealing Symptoms. Not but that all symptoms are in a sense re- 
 vealing, but these in a special and emphatic manner, since they disclose 
 the fact of the existence of a tendency, which, although present from 
 birth, possibly has never been suspected. Symptoms of this kind 
 
BETROSPECTIVE SYMPTOMS. H'6 
 
 occur, as might be expected, in connection with powerful exciting 
 causes. Peculiar manifestations following the employment of special 
 drugs, or the introduction of special animal poisons, may rank under 
 this head. If a patient who receives the virus of smallpox develops a 
 hsemorrhagic eruption, or if acne follows small doses of iodide of potas- 
 sium, we may feel sure that in these occurrences we have a revelation as 
 to the peculiar idiosyncrasies of the individual. It is certain that those 
 to whom these events happen differ and have probably differed through 
 the whole of life, from others in whom similar causes are not followed 
 by similar effects. The touchstone by which these individuals' pecu- 
 liarities may chance to be revealed are innumerable. The behavior of 
 the vaccination sore and that of the primary sore often furnish to the 
 observer an unexpected clue to the peculiarities of the individual. 
 Sometimes the revelation concerns only the specific cause which has been 
 in action, but in others it extends much more widely. For instance, I 
 believe that a clean well-indurated chancre without tendency to ulcerate 
 or inflame rarely occurs, excepting to a person in sound health, and is 
 far more common in those of dark complexion than in the fair. An op- 
 posite tendency on the part of the sore by no means always reveals or 
 implies weak tissues or poor health, but it often does so in a definite 
 manner. In making inferences of this kind, however, we must guard 
 against the error of attaching importance to the state of the sore dur- 
 ing the first week, which is usually due rather to peculiarities in the 
 pus by which the contagion was effected, than to those of the recipient. 
 The syphilitic virus itself is, on the other hand, always probably the 
 same, and differences in its results are due to temperament, diathesis, 
 or, health-state of its recipient, and come into the class of revealing 
 symptoms. 
 
 Some of these phenomena, deserve, I think, another distinctive name, 
 and may be styled as Retrospective Symptoms. They reveal not that 
 which is to come, nor even that which is present, but rather that which 
 is past. In some cases it may be that their causes are still extant and 
 influential, but in many I believe that the symptoms in question occur 
 only at a considerable period after the termination of the activity of the 
 influence which gave it birth, and that they imply little or nothing as 
 to the present health of the patient or his future liabilities. They 
 
84 THE PEDIGREE OF DISEASE. 
 
 may, however, reveal a diathetic tendency, which by hereditary transmis- 
 sion may bud out anew in offspring. The explanation of this probably 
 is that they are associated with diatheses which manifest their existence 
 chiefly in middle or early periods of life. The term, retrospective symp- 
 toms, ought not, perhaps, to be applied to conditions which are simply 
 the remains of bygone disease, however useful in a like way such condi- 
 tions may be. It is rather to be kept for conditions which originate 
 late, and which, like slow-growing seeds, spring up long after the seed- 
 time. The best example which I can give of wiat I mean occurs in 
 the instance of xanthelasma palpebrarum. When xanthelasma is de- 
 veloped in various parts of the body in an adult, I believe it is always 
 associated with liver disease, and often with definite and severe jaun- 
 dice. In these instances it reveals a still extant hepatic diathesis, plus 
 probably some slight tendency to new growth and fatty degeneration. 
 In the far commoner cases, however, in which xanthelasma patches are 
 met with on the eyelids only, no such association is observed; a large 
 majority of those who show them have never had jaundice and are in 
 •no sort of danger of it. Many, however, have in former years suffered 
 much from bilious headaches, and if not actually from these, they have 
 experienced repeated temporary health disturbances, attended by dark 
 areolae around the eyes. It. is this fact which the patches in question 
 reveal, and they may occur for the first time long after all liability to 
 the disturbances in question have ceased. They are, ther^ore, retro- 
 spective, and I am inclined to think that in many cases they are solely 
 so, and that little or nothing is to be inferred from them as to the pa- 
 tient's future. In other cases — and perhaps not a very small minority 
 — the original liability still persists, and will continue to show its effects. 
 But even in these, xanthelasma patches are usually the product of 
 what is long past, and have required a very long time for their produce 
 tion. I have already spoken of certain other and very rare cases in 
 which xanthelasma occurs in young children — possibly in several mem- 
 bers of the same family— always in a multiplex form, and without any 
 association with disturbed health. In these curious cases I would sug- 
 gest that the retrospection is yet further back, and that they reveal the 
 fact that some predecessor has suffered from liver disorder, or possibly 
 been the subject of xanthelasma itself. 
 
It is true of a number of morbid states which have received special 
 names, and are often spoken of as if they were complete in themselves 
 and distinct from all others, that their chief interest for the nosologist 
 lies in the fact that they are symptomatic of diathesis. Their occur- 
 rence reveals the states of peculiar health into which the persons show- 
 ing them have respectively fallen. Thus, as we remarked when dealing 
 with the subject, enlargement of the thyroid gland, when endemic, re- 
 veals a diathesis which may end in great degradation of the physical 
 state generally, and we ought by no means to be content to name it 
 bronchocele, as if in that terra we had denoted the whole malady. I 
 propose now to take up in succession a number of names which denote 
 according to custom distinct -diseases, and to ask concerning each what is 
 its symptomatic value, what does its occurrence reveal, how far may its 
 existence help us to the discovery or recognition of the health peculiari- 
 ties of the individual. 
 
 We will take first Acne. Under this name conditions which differ 
 much from each other are grouped, but my impression is that the 
 grouping is to a large extent natural, since they really are closely re- 
 lated. All forms of acne have this in common, and they are due to 
 morbid processes occurring in or around sebaceous glands, and further, 
 that their commonest site is the face, with the exception, perhaps, of 
 white acne or milium, which is due to congenital occlusion of some of 
 the gland orifices and accumulation of white sebum under a thin trans- 
 parent pellicle of epidermis. All are, at one stage or another attended 
 by congestion or inflammation. Their differences depend probably 
 npon differences in the character of the skin in different persons, differ- 
 ences in age, and modification in the ordinary causes. In order that 
 acne should occur, it is essential in the first/ place that the sebaceous 
 system should be largely developed, and the skin moderately thick. 
 These conditions given, we shall then be able to watch the play of vari- 
 ous influences, local and general, upon their subject's health in produc- 
 ing its various forms. If his state of tone and vigor remain perfect, 
 probably his glands will continue to elaborate and pour forth their se- 
 cretion, without any disturbance. No accumulations will occur, and 
 no secondary congestion around the glands will be observed. But the 
 slightest, the most temporary disturbance of tone may derange the 
 
86 THE PEDIGBEE OF DISEASE. 
 
 function of these glands, and may permit the retention of a thick secre- 
 tion, or favor the occurrence of inflammation around an irritating plug. 
 How rarely do we witness the occurrence of acne in any form before 
 puberty, and how frequently do we obtain proof, after .that period, that 
 the influence of the sexual system is all-potent in so disturbing the tone 
 that acne spots are produced. In girls menstruation is often attended 
 regularly every month by fresh eruptions of acne, and in boys nocturnal 
 emissions frequently have the same effect. If, however, the integument 
 were originally thin and not greasy, then it is possible for the tone to be 
 very seriously damaged by the causes adverted to, and yet no acne may 
 be produced. In such cases pallor of skin may be the only result. In 
 others in which there is less than usual proneness to inflammation, and 
 perhaps very slight disturbance of tone, a peculiar form of lichen-acne, 
 or very chronic persisting enlargement of the glands without conges- 
 tion, may occur. This is seen chiefly in the temples and forehead, and 
 in the male sex it is often coincident with similar long persisting en- 
 largement of the glands on the penis and scrotum. The location of 
 acne on the face is probably often explained by pre-existing peculiarities 
 in the state of the skin of the face. Some get acne almost solely on the 
 chin, or on the chin and cheeks, and these are almost always those in 
 whom the nose is specially thin. On the other hand, those in whom 
 the nose and skin generally are thick become liable, when acne is de- 
 veloped, to have the cellular tissue around the glands implicated as well 
 as the glands themselves. Thus, tuberose indurations of a very chronic 
 nature may be produced, which, if in adult life the causes of aggrava- 
 tion remain, may advance from what is known as acne tuberosa to the 
 most grotesque deformities. Acne is very constantly hereditary, the 
 same form often prevailing in several members of a family, and acne 
 tuberosa, I believe, often descends in several generations from father to 
 son. I have not seen acne tuberosa more than once in women, and in 
 that instance a sister of the patient had common acne, and her male 
 relatives had shown the tuberose form. The pustular or common form 
 belongs to youth, the rosaceous or erythematous to adult life. If, then, 
 we attempt to reply to the question "What does acne in its various 
 forms imply?" we should, I think, have to answer that in the first 
 place, it denotes original and heritable peculiarity in the structure of the 
 
skin; next, that its common form in young persons usually implies 
 greater or less disturbance of tone in connection with the sexual system, 
 and that its rosaceous form results from dyspepsia, attended by flushing 
 of the face after meals. The tuberose variety implies original pecu- 
 liarity of structure, and is often aggravated by dyspepsia and intemper- 
 ance. Common acne is almost constantly attended by proofs of en^ 
 feebled circulation, such as cold feet, and often by constipation. 
 Closely associated with acne is the liability to styes, to some forms of 
 sycosis, and to boils. "With these exceptions I know of no forms of 
 skin disease which are due to the same class of causes or denote the 
 same conditions of health. 
 
 A few words may next be said as to the symptomatic meaning of Ecze- 
 ma. This symptom is in a large majority of instances so far local that 
 it is curable by local measures, and scarcely, if at all, by constitutional 
 ones, whether drugs or restrictions as to food. Yet it is probable that 
 there is always a minor degree of constitutional proclivity and this is 
 sometimes proved to be hereditary. In a few cases, dietetic restrictions 
 do appear to have important influence, as for instance, the forbidding 
 of milk and sugar. I have already alluded to the remarkable way in 
 which eczema appears to aggravate itself, and when once it has begun 
 is its own source of extension. Probably a great many cases which be- 
 come severe and general, might have been stopped in the beginning by 
 appropriate local treatment. In most forms of eczema arsenic is use- 
 less, and this fact serves to detach it definitely from the psoriasis group. 
 There are, however, certain forms of nummular eczema in which well- 
 margined patches are scattered symmetrically over the limbs and trunk, 
 in which the disease approaches very closely to a form of psoriasis, and 
 is more or less under the control of the specific for that disease. Put- 
 ting aside a very large number of mild or local cases, which are clearly 
 due to local causes, we encounter severe eczema in the following forms: 
 First, as a disease of the dentition period of infancy, or what is often 
 equivalent, the lactation or milk-food period. Second, as a most per- 
 sisting and troublesome eruption affecting only special regions in chil- 
 dren and adults, as for instance, the hands, the lips, and the anus. 
 Thirdly, as a general and severe eruption in advanced adult or senile 
 periods of life. It is a noteworthy fact that wheii infants who have 
 
88 THE PEDIGREE OF DISEASE. 
 
 suffered very severely get well, they usually get quite well, and remain 
 well through life. General attacks affecting the whole body occur for 
 the most part near the extremes of life. Applications containing tar, if 
 weak enough, will almost always both prevent and cure eczema. Sea 
 air is often definitely advantageous, and the disuse of milk and sugar 
 are often important. With such facts before us can we find answers to 
 the questions: — Is eczema usually a sign of gout, or of any allied condi- 
 tion of defective digestion ? Is it catarrhal ? Is it due to structural 
 idiosyncrasy of the integument ? I should incline to reply that it is 
 certainly not catarrhal in any correct use of the word. It is not pro- 
 duced by the common causes of catarrh, nor does it display the clinical 
 course of all catarrhs, in the tendency to spontaneous recovery and fre- 
 quent repetition. Next, in many cases it does imply a minor degree of 
 mal-assimilation allied to gout, and is benefited by abstinence from beer 
 and wine. Eecent experience has led me to believe that the offending 
 article is often milk, and to think it of importance to restrict it as much 
 as possible. In very many, a large majority of cases, there is no true 
 gout either in the patients or relatives. 
 
LECTURE TI. 
 
 Me. President aitd Gentlemen-. — There is yet one other skin dis- 
 ease of such extreme interest in varied directions in reference to ques- 
 tions of diathesis, that I feel obliged to bring it in some detail before 
 you. I refer to Lupus; and I comprise under that name not alone the 
 common form, but certain other more or less rare varieties of the proc- 
 ess, which I trust to be able to claim as certainly belonging to the lupus 
 family. I am not about to trouble you with any detailed description 
 of those several forms, but in order that the questions as to causes, re- 
 lationships, and the diathesis behind them, should come clearly out, it 
 , is necessary that I should state briefly a few facts. 
 
 Concerning common lupus, then, I would assert that it is well known 
 that it begins as a cell growth in the corium, that it always begins as a 
 single patch, and always spreads at its edge by the infection of the adja- 
 cent skin, and that it very usually tends in the end to become multiple. 
 Its multiplicity, as well as its local spread, is due to its infective power, 
 and its secondary growths are almost always placed in close proximity 
 with the parent one. It never in any case, however extensively multiple 
 its patches may be, shows any tendency to symmetry; in all these fea- 
 tures its clinical history resembles that of a local cancer. That which is 
 true of the locally restricted form of epithelioma known as " rodent 
 ulcer " is true also of common lupus. Both are slowly progressive new 
 growths which after a time inflame and ulcerate, and then cicatrize. 
 Both are curable by free measures of local extirpation and by those only. 
 You cannot influence either except in the most minor degree by any 
 remedies which appeal to the general health. Neither shows any power 
 of producing gland disease, nor any tendency to spontaneous ameliora- 
 tion. The one is a disease chiefly, however, of early life, and the other 
 of adult age. The varieties which common lupus presents do not ofEer 
 us anything very exceptional to what I have said. According to the con- 
 stitution of the individual, the state of health, the kind of diet, and the 
 
 •89 
 
90 THE PEDIGREE OF DISEASE. 
 
 climate, lupus may inflame and ulcerate much or little, ajid in connec- 
 tion with these almost accidental differences, the old, — and I trust now 
 abandoned — terms exedens and noti-exedens came into use. It may vary 
 also very much as regards its restriction to a single original patch, or its 
 tendency to multiplicity. Sometinies we see a single patch steadily 
 spreading at its edge through the greater part of a long life, and never 
 showiag any tendency to produce new ones. This probably depends 
 upon comparative vigor of constitution and a lesser degree of suscepti- 
 bility. The explanation of the secondary patches when they occur is, 
 in all probability, that they are the result of infection. As already 
 stated, the multiplicity is never spontaneous. It is not, I think, beside 
 the mark that I should ask attention to the methods of cure which have 
 been proposed for lupus, as being indications of some affinity with the 
 diathesis of malignant diseases. We have lately been taught by Pro- 
 fessor Volkmann that every portion of the diseased tissue should be 
 most carefully eradicated by the scoop. But his proposal had nothing 
 whatever in it that was original in its theory; for long previously we 
 had all been accustomed to act on the same principle and to seek by the 
 knife, the caustic, or the cautery, to utterly eradicate every fragment of 
 the. new growth. If I am not mistaken, we owe to Mr. John Gay, — to 
 whom surgery is indebted for many other practical suggestions — the radi- 
 cal proposal that the lupus patch should be cut out with the knife. It 
 is essential that whatever method be adopted it be pursued unflinchingly 
 and over and over again if needed.' In this way lupus may be cured, 
 and it is not too much to hope, now that this principle is becoming 
 widely understood, and the profession is becoming bold in its practice, 
 we shall before long witness a great diminution in the number of those 
 who are disfigured by it. My object, however, in mentioning the success 
 of vigorous local measures is not to enforce a lesson in therapeutics, but 
 to intensify our conception of common lupus as a local new growth pos- 
 sessing infective properties. I might add that it often begins from 
 some slight local injury, a sting, an abrasion, or a chilblain. Amongst 
 the interesting varieties which common lupus presents we have a rare 
 form, which we may suitably call " acne lupus," which occurs in scat- 
 tered spots over the face, these spots being evidently connected with 
 sebaceous follicles, and often with previously-existing acne pustules. 
 
xiiji iiujrua j^Ainiiji. 
 
 Their arrangement, however, I believe, never follows {hat of acne in 
 being symmetrical, but always obeys the, law of lupus, in that the secon- 
 dary tubercles are more or less near to the parent one. In another vari- 
 ety, lupus attacks mucous membranes and produces slowly spreading 
 ulceration, attended with papillary outgrowth. That lupus of mucous 
 membranes as we see it affecting the conjunctiva, the gums, the palate, 
 etc., is really lupus is proved by its very frequent association with well 
 characterized disease in the skin. In another extremely rare variety, of 
 which I have seen but a few examples, the lupus growth is exceedingly 
 trivial, does not ulcerate at all, spreads rapidly at the edge, leaving be- 
 hind it a thin, supple, and healthy scar. In yet another variety it re- 
 ceives modification probably from the part in which it occurs. It is but 
 seldom that we see well-characterized lupus on the hands or feet. But 
 we often encounter a form of disease which takes its place, in which 
 there is less evidence of new growth and more of inflammation and ten- 
 dency to papillary hypertrophy. To this group, the form of inflamma- 
 tion due to dissection wounds on the hands — necrogenic warts of Dr. 
 Wilks, or necrogenic lupus, I think belongs. There is yet another vari- 
 ety in which the surface of the lupus patch does not ulcerate, and is not 
 raised, but weeps, like an eczema, presenting a condition which would 
 at first sight, and certainly by the inexperienced, be mistaken for eczema. 
 The facts to which we appeal, in proof that all these very different look- 
 ing inflammations of the skin are really lupus, are that they all take 
 origin at a single spot,> spread slowly but constantly at their edges, and 
 whether they ulcerate superficially or not, always leave a cicatrix where 
 they have passed. I do not think that there can be much hesitation in 
 accepting the statement, that a disease which presents these features, 
 and is not either a cancer or syphilitic, must be a lupus. 
 
 We have arrived, then, at the end of our first stage in the inquiry, 
 and have seen that this peculiar form of new growth in the skin and 
 mucous membranes to which young persons are liable may, while observ-r 
 ing identity in essentials, manifest very peculiar differences in external 
 appearance. It may be in single patches or multiple; it may look like 
 itself, or like an acne, a lichen marginatum, or an eczema. These differ- 
 ences have more to do with the original differences in the texture of the 
 skin which is attacked, than any other class of causes. Let us notice 
 
92 THE PEDIGREE OF DISEASE. 
 
 the peculiar thinness and delicacy of the skin in the boy who furnishes 
 us the example of what I have called lupus marginatus, in which ex- 
 ceedingly little growth and no ulceration occurred. "We have now to 
 take another step and to encounter another process with far more im- 
 portant differences. The diseases which are known as Iwpus erythema- 
 tcsus, and its variety lupus sebaceus are more than a mere modification 
 of common lupus. They are distinct varieties, or, if one dared to use 
 such a word, they are almost species. They manifest relationships with 
 other type-forihs of skin disease, almost as close as those they bear to 
 common lupus. Had it not been for the fact that the common form and 
 the erythematous form, often exist together or slide into each other by 
 insensible gradations, we might have been tempted to prefer to call 
 erythematous lupus by some other name. Its most important difEerence 
 of feature is that it usually occurs symmetrically. Thus there is far 
 more reason to believe that it is due to a constitutional peculiarity, than 
 is the case with the absolutely non-symmetrical and local lupi,xs. The 
 arrangement of the bat's body and wings, on the nose and cheeks, in 
 erythematous lupus is well known. The parts affected next to the nose 
 and cheeks are almost always the ears, and next to them the backs of 
 the hands. In this spreading there is no continuous connnection be- 
 tween the patches. They are separate from each other, and apparently 
 independent. The evidence as to multiplication by infection is far less 
 strong than it is in the common form, though there can be not the slight- 
 est doubt that this kind of advance does take place at the edges of the 
 patches. Eemembering what I had to advance in our last lecture in 
 reference to the possibility that all inflammatory processes may be capa- 
 ble of infecting the blood, I am unwilling to admit, even when we see 
 lupus erythematosus on the backs of both hands, whilst the whole of the 
 rest of the upper extremities and trunk remain free, that we have con- 
 clusive proof that these secondary manifestations are independent of the 
 original patches on the face. The symmetry cannot possibly be due to 
 any other cause than pre-existing proclivity of tissues; but it is just pos- 
 sible that it is not independent of an infective process also. At any rate, 
 it is true that this disease is wonderfully symmetrical; the ears, the 
 cheeks, and the backs of the hands show exactly the same conditions on 
 the two sides. The variety to which the name sebaceous is given is 
 
V THE ALLIANCES OF LUPUS. 93 
 
 often not erythematous at all. There may be no redness and no swell- 
 ing, but the skin becomes dry, rough, and shrunken, and the orifices of 
 the sebaceous follicles are very conspicuous, like the inner side of a nut- 
 meg-grater. This form is also accurately symmetrical, but it rarely 
 leaves the face. If you see it on the nose you may look for it on the 
 ears, and in the middle of the concha of each, — Just where in acne a 
 group of comedones is. often seen, — there will be a little patch of lupus. 
 Lupus sebaceous and lupus erythematosus are frequently mixed in the 
 same case, and they are probably the same disease modified by peculi- 
 arities in the skin. Although I have described them both as usually 
 symmetrical, not unfrequent exceptions occur. Under all conditions 
 they sliow their alliance with lupus by leaving the skin which they have 
 affected in a state of scar. I suggested that lupus erythematosus had 
 alliance with other skin diseases, and I was thinking especially of psoria- 
 sis and those modifications of nutrition known as chilblains, and my 
 suggestion will now be that it owes its peculiarities to the mingling in 
 varying proportions of these two diatheses with that of lupus. As re- ^ 
 gards chilblains, it is sometimes, when the ears and the backs of the 
 hands are affected, quite impossible to differentiate between them and 
 lupus erythematosus. The latter, like chilblains, is always worse in cold 
 weather, and it usually occurs to persons of feeble circulation, in whom 
 venous congestion easily occurs when the surface is chilled. Its alliance 
 with psoriasis is shown, not alone by its symmetry, but by the fact that 
 in exceptional instances the scaly patches may be seen on the tips of the 
 elbows, with now and then a diffuse psoriasis condition of the whole sur- 
 face. Children and young persons are but rarely the subjects of lupus 
 erythematosus, nor does it usually attack those in whom the skin is 
 thick.- 
 
 I think we may assert respecting lupus as a whole that it is a sort of 
 cross produced by tendencies at once to scrofula and cancer, and that it 
 receives many modifications from peculiarities in the patient's skin and 
 his morbid tendencies in one or the other direction. If he has a degree 
 of tendency to the psoriasis diathesis it will assume the erythematous 
 form, and it will be especially prone to attack the extremities if it en- 
 counter also the proclivities to chilblains. 
 
 I have yet left for consideration another variety of lupus concerning 
 
94 THE PEDIGREE OF DISEASE. 
 
 which a few words must be said. It is a disease which differs much from 
 all forms which we have described, and yet I submit that it is really a 
 lupus. I know as yet of but four recorded examples of it. The late 
 Dr. Tilbury Fox showed at a meeting of the Pathological Society a young 
 man on whose thigh were two different and very peculiar conditions — 
 one being a congenital port- wine stain and the other a persisting vesicular 
 eruption which had been developed at a later period. As a result of 
 microscopical examination, Dr. Fox believed that the vesicles in question 
 were in connection with the lymphatic trunks and spaces. At the same 
 meeting I mentioned two cases in which I had for a considerable time 
 taken much interest, but which we neither of us then thought to be ex- 
 actly similar. A third case has subsequently come under my observation, 
 and I have now no hesitation in believing that the four are examples of 
 the same malady, and that the lymphatic spaces and the lynjphatic trunks 
 are really implicated. Whether it deserves the name of Lupus Lymphati- 
 cus I must leave to your judgment. All the four patients were boys; in all 
 the disease had existed for several years; in all'it was slowly spreading at 
 the edge, and producing, near to the parent patch, secondary ones, which 
 were apparently due to infection. In none of the cases was there ulcera- 
 tion, and in all the eruption consisted of little firm resisting vesicles which 
 showed no tendency to rupture, and were aggregated into confluent 
 groups. Upon these vesicles and at their bases were little tufts of capil- 
 laries which were almost nsevoid in character. By microscopic exami- 
 nation of portions cut from all three cases, I have satisfied myself that the 
 lymphatic trunks are dilated, and further, that there is a new cell-growth 
 around them exactly like that of common lupus. So similar is this cell- 
 groTvth to that of lupus that a very able microscopist, who examined one 
 of my slides, took it for a specimen of that disease. It is right that I 
 should add that in this microscopic examination I have been much as- 
 sisted by Dr. Sangster, Mr. Eobert Parker, and my eldest son. My be- 
 lief is that the malady in question bears the same relation to the lymphat- 
 ics that lupus erythematosus does to the blood-vessels, and that it is an 
 instance of a new growth assuming special clinical features in connection 
 with the peculiarity of the speciaL tissue in which it takes its origin. 
 As in cancer everything depends on the tissue first affected, whether the 
 growth is a melanosis, an epithelioma, or a scirrhus, so in lupus perma- 
 
IKITIS AS A KEVEALING SYMPTOM. 95 
 
 nent modifications are stamped on the process according as it begins 
 around the sebaceous glands, the blood-vessels, the lymphatics, or in the 
 corium. When the type has been once taken it will be retained. 
 
 The various forms of Iritis are of peculiar value as indications of dia- 
 thesis. Its occurrence in infancy, a very rare event, is usually indica- 
 tive of syphilis. In adolescent periods, and early adult life, we have 
 difEerent forms of iritis, all of which generally imply the inheritance of 
 gout. This inheritance is, in such cases, often modified by^other indi- 
 vidual peculiarities, such as feebleness of circulation and proneness to 
 chilblains. When this is the case, a very peculiar form of multiple 
 arthritis which begins in the last joints of all the digits, and often afEects 
 them exclusively, is sometimes seen. The explanation of last-joint- 
 arthritis is doubtless to be found, as I have just suggested, in the pecu- 
 liarity of circulation which in later life gives tendency to symmetrical 
 gangrene of the extremities, as so well described by Eaymond, and more 
 recently amongst ourselves by Dr. Southey, It is not, however, due 
 to this alone. There is always joined with it an inherited tendency to 
 gout. The form of recurrent iritis which we meet with so frequently 
 in adult men, but occasionally in women also, in which the attack is 
 sharp and severe, the interval of immunity complete, and the recurren- 
 ces take place once a year, or oftener, is, I believe, distinctly an indica- 
 tion of rheumatic gout. It does not very often happen to those who 
 suffer severely from declared gout, and it is very rare in connection 
 with rheumatism only. We meet with it in those in whom there is in- 
 herited proclivity to gout, who have lived rather freely, who are sus- 
 ceptible alike to weather and to diet, but who have never themselves 
 had an outbreak of true gouty arthritis. The fact that this form of se- 
 verely paroxysmal iritis occurs much more frequently in men than in 
 women, supports the general statement which I have just made. In 
 women of middle age, or a little past it, we encounter iritis in another 
 form, as an insidious disease, attended by a little conjunctival redness, 
 but with some sensation of heat and irritability, and gradually, without 
 any definite paroxysms, producing extensive adhesions. The little ex- 
 acerbations which attend it are often more definitely influenced by ex- 
 posure to cold and wind than by diet. This form of iritis is, I believe, 
 almost invariably a consequence of a remote inheritance of gout. 
 
96 THE PEDIGREE OF DISEASE. 
 
 I tried in a former course of lectures to give a definition of the word 
 Catarrh which should enable us to employ it for more accurate clinical 
 purposes than it is often used. I suggested tliat it should be held to 
 imply identil^ in cause, and not similarity in result. There is surely 
 no good reason why all forms of inflammation of mucous membrane, at- 
 tended by free discharge, irrespective of their causes, which are often 
 very different, should be called "catarrhal." On the other hand, if we 
 use the word in the sense which I contend for, we shall find it apphca- 
 ble to other inflammations besides thope of mucous tissues. In so doing 
 we shall construct a large and perfectly natural group of maladies. 
 Whatever is the result of catching cold is catarrhal ; conditions which 
 follow from other and dissimilar causes, however similar their results, 
 ou^ht to be refused that name. The catarrhal diathesis, using the 
 word in this sense, is one of the three fundamental ones. It is not due 
 to any specific or any specialized cause. Every organization possessing 
 a nervous system must be supposed to be capable of manifesting it, for 
 its essence consists in proneness to inflammatory congestions excited, in 
 a reflex manner, through the influence of cold applied to the surface. 
 The susceptibilities of the nervous system, however, in this direction 
 differ, as we all know well, very greatly in different individuals. These 
 differences are hereditary, and may easily become the possessions of 
 families or of race. Not only do individuals differ in the degree of re- 
 flex susceptibility, but they also vary much as to the special tissues or 
 organs which are most prone to suffer under it. Thus, some catch 
 cold, almost solely in the mucous membranes of the nasal passages and 
 pharynx; in others, the tonsils, throat, and larynx are more prone to 
 suffer; in others the bronchial mucous membrane; and in others the 
 stomach and bowels, or even the liver. Although I shall admit rheu- 
 matism to the rank of a universal diathesis and place it for the present 
 in this respect side by side with scrofula and catarrh, yet in doing so I 
 shall have to suggest, as indeed I have repeatedly done, that rheuma- 
 tism after all is only the catarrhal diathesis affecting the joints. Let 
 me state a few general facts respecting catarrhal affections, and then 
 pass on. First, it is a great mistake to imagine that only those of deli- 
 cate constitution, and accustomed to much protection from weather, 
 etc., are liable to catch colds. Farm laborers and others engaged in 
 
THE CATARRHAL DIATHESIS. 97 
 
 labgrious oi\t-door pursuits, often show this susceptibility very definitely, 
 and suffer yery severely. My impression is, however, that the peculiar 
 degree of susceptibility which causes its possessor to experience slight 
 catarrhal symptoms on every little variation of accustomed exposure, is 
 rarely reached in them. They take cold but seldom, and when they 
 do, it is in connection with some exceptional cause, and the catarrh de- 
 velops with exceptional severity. I have, however, met with some, re- 
 markable instances of extreme development of the catarrhal diathesis in 
 those who are constantly out in the open air. Especially well I recollect 
 an apparently robust farmer, who coiild do anything he liked out of 
 doors, but who could not sit in a carriage with an open window, or for 
 ten minutes with his feet on a stone floor, without Catching cold. It 
 is a general law of all catarrhal affections, and well recognized in the 
 experience of every one, that they are spontaneously curable, but very 
 liable to recurrence. 
 
 AH forms of catarrh pass off spontaneously after a while, and in many 
 persons their duration is tolerably regular, and the period of immunity 
 often keeps to the same average length. When we find the results of 
 a catarrhal inflammation threatening to become lasting we feel sure that 
 the diathesis is a complicated one. Tt is one which very easily mixes 
 itself up with other forms of ill -health. 
 
 We define scrofula to be a state of the solid tissues, and more especi- 
 ally of the lymphatic system as a whole, in which there is peculiar 
 proneness to chronic inflammations resulting in products more or less 
 peculiar and specialized. Modern discoveries will perhaps lead us to 
 believe that those specialized products are usually accompanied by the 
 presence of particulate organisms which are neither part of, nor derived 
 from, the original tissues. Be this as it may, we shall have to study 
 the scrofulous diathesis, and the predisposing causes of scrofula. Just as 
 before. We shall still have to ask what are the conditions which favor, or 
 otherwise, the development of the bacillus in question. Even the firm 
 est believers in the new facts admit this. Looking, then, upon scrofula 
 as a permanent and heritable condition of the tissues favoring chronicity 
 in all inflammatory processes and directing them towards more or less 
 specialized ends, it is easy to see that in such individuals catarrhal 
 
 attacks may depart from their usual type, and may not show their natu- 
 
 7 
 
98 THE PEDIGREE OF DISEASE. 
 
 ral tendency to spontaneous disappearance. As a matter of fact, we 
 are only too familiar witli the danger of catarrhal attacks in scrofulous 
 subjects. 
 
 But it is not alone in the scrofulous that we encounter risks in con- 
 nection with catarrh. Those in whom the tissues have undergone senile 
 degeneration and those, too, who although not old have become seri- 
 ously enfeebled by other causes, often show an inability to shake off 
 catarrhal attacks, and a similar result is sometimes brought about under 
 the law of habit, when catarrhal attacks have been exceptionally fre- 
 quent and severe. Apart from the risk of lapsing into chronic disease, 
 catarrhal inflammations are in themselves not unfrequently dangerous 
 to life. Many of the forms of acute bronchitis and pneumonia, and 
 some forms of enteritis, peritonitis, and pleurisy, are distinctly catarrhal 
 in their nature — that is, they result from the exposure of an individual 
 to the ordinary causes of a catarrh — and in many of these the popular 
 expression is verified, " he caught his death of cold." Eheumatic fever 
 very often, as is well known, acknowledges a similar cause; and re- 
 specting it and the other acute and dangerous catarrhal inflammations, 
 one general statement is true — that if the patient can only live through 
 the attack it will in due course pass off, and pass off completely, leaving 
 him again in good health. This remarkable facility of spontaneous^ re- 
 covery which is a feature of all catarrhal, or, in other words, of all 
 reflex nervous inflammations, has placed physicians in great difficulty in 
 coming to any satisfactory conclusions as to the relative merits of differ- 
 ent plans of treatment. I will not say that cases of acute pneumonia, 
 or acute rheumatism, or severe catarrh recover as well under one plan 
 as another, I should be going far out of my province to make any such 
 insinuation, and I should be saying, too, that which, with my small 
 amount of information, I certainly do not believe. This, however, I 
 must repeat — that there is in each and all of the examples of this type 
 of inflammatory attack, a natural tendency to recovery at a certain 
 stage, which the student of therapeutics must always keep in mind. 
 Although I have spoken of cold, in combination with damp, as if it 
 were the sole cause of catarrh, it must by no means be supposed that 
 this is exactly so. With the changes in temperature there are doubt- 
 less, frequently coincident and very influential, certain electric disturb- 
 
CATABEH AND RHEUMATISM. 99 
 
 ances, of which it is very difficult to take exact appreciation. To these 
 we must refer the great prevalence of catarrhal and catarrho-rheuma- 
 tic affections at certain seasons, and during the prevalence of certain 
 winds. This prevalence is sometimes such as to suggest, as in the case 
 of influenza, that the air must carry with it particulate and contagious 
 germs. The sum total of what are included in the meteorological con- 
 ditions termed weather must count as causes of catarrh. 
 
 I have placed the rheumatic diathesis with the catarrhal and the 
 scrofulous, as one which is universal, and in which all human beings 
 share in some degree. What I have said as regards the laws of catarrhal 
 inflammation apply very closely to those which are rheumatic, for the 
 two are as regards their causes, very nearly allied. Kheumatism like 
 catarrh is usually transitory, especially when it occurs in the young. 
 As with catarrh, so with it, when the aged are its subjects there is danger 
 that it may become chronic or even permanent. Like catarrh, it may 
 mix itself with scrofula or be modified by any other influence which 
 disturbs the general health. The efEect of malaria upon the system is 
 often seen to much increase the proclivity both to catarrh and rheu- 
 matism. One other diathesis so very frequently mixes itself up with 
 rheumatism, and the two in hereditary transmission become so intimately 
 united that it is a matter of considerable difficulty to ascertain how far 
 rheumatism pure can go. We can, however, have little hesitation in 
 admitting that it may be the parent not only of rheumatic fever, of 
 transitory rheumatic pains in joints, fascia, and muscles, but of chronic 
 crippling arthritis, in which almost all the joints are involved, and in 
 senile periods of the slowly destructive arthritis which wears away the 
 cartilage and eburnates the bones. Further, I think we may grant that 
 it is not unfrequently the parent of sciatica and lumbago. All the 
 affections which I have mentioned occur occasionally to those in whom 
 there is no reason to suspect a gout complication; and, what is a still 
 stronger fact, they are met with occasionally in the lower animals. 
 Having said this I must not delay to add that in a great many of the 
 exaggerated and peculiar forms of them which we witness in the 
 human subject, the cause of the peculiarity is an hereditary complica- 
 tion of gout. When this complication exists it shows its power, we 
 may suspect, by inducing a permanent modification of tissue; and it is 
 
100 THE PEDIGREE OF DISEASE. 
 
 to this modification tliat the peculiarities in the processes are due. 
 Hence the impossibility, under many conditions, of discriminating be- 
 tween gout and rheumatism. We can for the most part easily tell, in 
 any individual case, what the causes which have provoked the attack 
 have been, and we can assign them on the one hand to those of rheu- 
 matism or on the other to those of gout; but we cannot estimate with 
 any chance of certainty the previously acquired proclivities of the tissues. 
 There is yet another source of fallacy, that we are by no means always 
 acquainted with the condition of the patient's health at the time of the 
 attack. If a patient already predisposed to gout, in his kidneys, his 
 tissues, or his blood, be exposed to the exciting causes of rheumatism 
 he will have one of those attacks which you yourself, Mr. President,' 
 have so well described, and about the nature of which there has been 
 some controversy. There will be difference of opinion as to whether 
 such an attack should be called rheumatic fever or generalized gout; 
 and the solution of the question is, I suspect, to be found in the fact 
 that it is both. Two sets of causes have been at work, and the result 
 has been a mixed one. 
 
 When a little white tophus is seen on the ear, the merest tyro can 
 read its lesson, and the veriest sceptic dares not refuse its revelation. 
 It is both retrospective and prospective in its significance; we know that 
 the patient's kidneys have become unsound, and that he has failed, in 
 the past, in the due depuration of his blood. We know that this loaded 
 blood condition must have put him in danger of attacks of arthritis; 
 and that in all probability he has suffered on many occasions from 
 acute and 'very painful inflammations of some of his smaller joints. 
 We know further that changes have taken place in many of his tissues, 
 and especially that the walls of his blood-vessels have become thickened. 
 Looking into his future we know he is in danger not only of other 
 attacks of arthritis, but that, however carefully he may restrict his diet 
 and manage his mode of life, it is probable that the renal and arterial 
 changes will increase and bring with them their peculiar inconven- 
 iences and risks. We know further that if a man in such a state 
 should have children, they will, in spite of the utmost care in avoiding 
 the dietetic causes which originally produced it, inherit some of the 
 
 ' See Spencer Wells on Gout, p. 66 ; also Garrod on Gout, p. 43. 
 
RHEUMATISM AND GOUT. 101 
 
 peculiar tendencies which he had acquired. . Where the inheritance will 
 stop, how far it is possible for one structural peculiarity to be isolated, 
 and to be inherited apai-t from others, we do not know. There is, 
 however, I would suggest, good reason for believing that in families in 
 which, either by accidentally changed conditions, or by intelligent fore- 
 sight, several generations have been carefully exempted from the 
 causes of gout, its existence, in times long past, may still be shown in 
 the perpetuation of one or other, more or less isolated, tendency to 
 structural disease. It is under such conditions that not a few of the 
 forms of rheumatic gout occur, although in others, and perhaps a large 
 majority, it is rather the fact that the exciting causes of gout have by 
 no means been wholly suppressed. In this way we may have to rec- 
 ognize, as lineal descendants of gout, maladies which occur in those in 
 whom we can by no means prove its persistence. I have referred re- 
 peatedly to the facts which favor the belief that the hjemorrhagic dia- 
 thesis itself may, perhaps, belong to this category; and in a former 
 course of lectures I analyzed the facts contained in Dr. Wickham 
 Legge's able monograph on this subject. During the past year some 
 very interesting cases have come under my observation, which serve to 
 give support to it, and to lead to the conclusion that many, if not most, 
 forms of intractable haemorrhage are in connection with hereditary 
 peculiarity of the arterial *system, derived from gouty progenitors. I 
 will mention only three, and these very briefly. A gentleman who 
 consulted me a few weeks ago, with cataract and diabetes, told me that 
 he had ,been most of his life liable to very profuse attacks of haemor- 
 rhage. In early life they had been alarming, and sometimes so fre- 
 quent as to be almost constant. They were always preceded by a sense 
 of weight and discomfort at the epigastrium; and provided the haemor- 
 rhage was not too profuse he had usually felt relieved by it. There 
 was a strong inheritance of gout, and he had himself suffered from 
 several attacks. A school-boy was sent to me by Mr. Harrison, of 
 Braintree, on account of repeated and alarming attacks of epistaxis. 
 They had been so profuse and so frequently recurrent that he had lost 
 much of his color and strength. The point, however, which most 
 caused anxiety was that his elder brother had died of it. In him the 
 liability had commenced at thirteen and a half, had persisted for two 
 
102 THE PEDIGREE OF DISEASE. 
 
 years, and finally, after continuing for four days, it ended in death. 
 Their paternal grandfather had suffered much from gout, and their 
 father at the age of twenty-two had had severe epistaxis. In the case 
 of a lady, now aged twenty-nine, and much out of health, I had the 
 following history: — She had always suffered from indigestion and rheu- 
 matic pains. At the age of seven she had epistaxis to such an extent 
 that the nostrils had to be plugged; and in spite of that measure it was, 
 during three days, expected that the attack would end fatally. She 
 once had bled to an alarming extent in consequence of tooth-drawing. 
 Her first menstruation had soaked the bed through; and ever after- 
 wards this function had been attended with losses so profuse as to have 
 greatly enfeebled her. There had been much gout on both sides of her 
 family, and she herself had had symptoms very like it. 
 
 I was unable, when examining this subject last year, to agree with 
 Dr. Wickham Legge in his opinion that oases of remarkable tendency 
 to haemorrhage, occurring, as it were, sporadically, should be kept 
 quite apart from the hsemorrhagic diathesis, in which we observe the 
 tendency to prevail in direct descent through many generations. It 
 may be that as a matter of convenience it may be well temporarily to 
 effect this separation, but it must, I think, be with the clear under- 
 standing that it is a conventional one. The hereditary cases are those 
 in which the idiosyncrasy has become deAiite and established; the 
 others show us the idiosyncrasy in connection with its original causes, 
 and, if I may so express it, in process of breeding. The cases of hsem- 
 orrhage into the vitreous in young men suffering from constipation 
 which have been collected by Mr. Eales, of Birmingham, and in many 
 of ^^hich no history of gout could be obtained, go with other facts to 
 make it probable that tendencies to bleed are sometimes met with in 
 association with other causes. My own experience as to retinitis hem- 
 orrhagica, blood patches in the conjunctiva, cerebral haemorrhage, epi- 
 staxis, and other allied disorders, leads me, however, to attach very 
 great importance to the history of inherited gout as their frequent 
 cause. 
 
 There is one subject which it is impossible to leave out of the account 
 in our estimation of the diathesis. It does not constitute a diathesis 
 in itself, but it complicates them all. I refer to the changes in the 
 
TONE IN CONNECTION WITH DIATHESIS. 103 
 
 state of the nervous system, or quality of the nerve force, which we 
 know as tone. By that word I suppose that we mean the power of pro- 
 ducing nervous energy. If we speak of the tone as low and poor, we 
 mean that there is but little vigor in resisting irritation, and that com- 
 paratively slight influences will evoke a large amount of disturbance. 
 That vigor depends, no doubt, upon the state of nutrition of the nerve- 
 cells themselves, and it may vary much in different parts. Thus, the 
 tone may be diminished in one nerve district and yet be good in others, 
 whilst in some instances it is reduced in all, simultaneously. A condi- 
 tion of great general exhaustion is by no means, however, always equiva- 
 lent with a state of low tone; it is necessary that the enfeeblement- 
 should pertain to the nervous system especially, in order that that term 
 should become applicable. Perhaps it is further true that in most of 
 the conditions in which derangement of tone is in question, the distur- 
 bance or enfeeblement has reference cldefly to that part of the nervous 
 system which controls the circulation. Whenever the circulation is 
 specially liable to reflex derangement, and congestions or their opposite, 
 occur with unusual facility, we are safe in declaring that the tone is 
 low. It is part of the business of the nervous system to duly regulate 
 the supply of blood to various parts, to prevent local arterial spasm, 
 and under the varying conditions of daily life to maintain the normal 
 balance of circulation. When this power is deficient the various causes 
 of disease act with greatly increased effect. In many cases loss of tone 
 may be so long continued and so great that we cannot but suspect that 
 it depends upon degenerative and permanent changes in the nerve cells. 
 Not only may loss of tone aggravate a diathesis, but many of these act 
 very efficiently in producing loss of tone. Thus the influence of mala- 
 ria is very definite in this direction, and is felt through very long periods. 
 But I cannot for the present dwell longer on this part of my subject. 
 
 The present is, perhaps, the most suitable place for me to interpolate 
 two emendations on former lectures. In my first lecture I adverted to 
 the want of observations for the purpose of estimating the relative fre- 
 quency of the different complexions in the British population. In 
 doing so, I omitted to mention the excellent work accomplished some 
 years ago by Dr. Beddoes, of Bristol. I had intended to mention it, 
 and should certainly have done so if I had remembered its extent and 
 
104 THE PEDIGREE OF DISEASE. 
 
 value. In a subsequent lecture I urged the importance of Lif e-Eeoords, 
 which should be kept in advance, ready to be produced to any medical 
 man who may be consulted, and especially comprising mention both of 
 family tendencies and of idiosyncrasies of the individual, and the dis- 
 eases which have been passed through. In making this suggestion, 
 which had long occupied my thoughts, I was not aware that the Collec- 
 tive Investigation Committee of the British Medical Association already 
 has in hand a scheme for its realization. I have since with great pleas- 
 ure been informed that such is the fact. 
 
 It is time that I should bring this lecture to a close, and with it will 
 end my present course. In doing this, I desire, gentlemen, to thank 
 you most sincerely for the very courteous attention witn which you have 
 listened to what I have advanced. Permit me at the same time to at- 
 tempt a very brief resume of the principal arguments. 
 
 We began by a glance at the praiseworthy and to some extent success- 
 ful attempts made by our forefathers by looking into a man's face to 
 determine therefrom his physical peculiarities and his liabilities to disease. 
 On examining the facts supposed to indicate "temperament" I was 
 obliged to conclude .that part of them were merely the characteristics of 
 different races; and another part, merely the products' of past disease — 
 personal or inherited. Thus it seemed that if race took its share, and 
 disease that which legitimately belongs to it, there was very little left to 
 be classed under the head of " temperament. " As regards diseases in 
 general, I suggested that the plan most likely to be productive of good 
 results is to classify the chief groups of morbid influences, and to en- 
 deavor then to associate with each the separate maladies and tendencies- 
 which are dependent upon them. To this object our last three lec- 
 tures have been devoted. We had previously endeavored to clear the 
 •ground somewhat by placing in a separate category a large number of 
 symptoms and of morbid manifestations which take their origin in in- 
 dividual peculiarity, quite apart from any recognizable tendency to 
 disease. I insisted that the domain of mere Idiosyncrasy is very large. 
 I suggested that these peculiarities may have had their origin remotely 
 in disease, but asserted at the same time that they have often existed 
 for many generations in complete freedom from any such association. 
 Whether I have succeeded in convincing you that it would be a con- 
 
CONCLUDING REMARKS. 105 
 
 Tenience in medical teaching and practice to reyive the old doctrines of 
 diathesis I do not know. To my own mind it does appear, T may con- 
 less, that the states to which I have sought to apply that name are 
 realities which it is very desirable to recognize. It seems to me, also, 
 that the habit of naming diseases as if they constituted separate and 
 complete entities has often a narrowing effect upon our pathological con- 
 ceptions, and leads to the overlooking of special causes. My endeavor 
 has been to look at disease not exclusively from before, but, so to speak, 
 to get behind it and trace its origin. Classification should surely de- 
 pend not upon external similarity, but relationship in cause. We 
 should seek to place diseases in natural groups, in connection with their 
 ancestral descent. The attempt to do this has, I fear, sometimes led 
 me into speculations as to the genesis of the different forms of diathesis 
 ■which may have seemed somewhat transcendental, and been possibly a 
 little wearisome. I can only plead that I have done my best to avoid 
 these faults, and I have been endeavoring to thread my way through 
 the mazes of a most complicated topic. The main conclusions as to the 
 diathesis which I have suggested for your acceptance are these: — That 
 there are three great universal diatheses dependent upon the very com- 
 monest causes of disease by which man, and not man only, has been 
 assailed from the most primeval times. These are — the catarrhal, the 
 rheumatic and the" scrofulous. Close to these come others of far less 
 importance, but of parallel natute, because they comprise us all in their 
 range of liability; the diathesis of senile degeneration and the diathesis 
 of malignant new growths. Next we have certain very important ones 
 which are widely spread, but by no means universal, since they depend 
 upon local exposure or personal habits. In this class we have the ague- 
 diathesis, the diathesis of rickets, those of bronchocele, scurvy, leprosy, 
 pellagra, a;nd gout. Respecting the diathesis due to malaria, I have 
 some doubts whether it ought not to be admitted to the dignity of a 
 primary or universal diathesis. If we go far enough back, probably the 
 whole human race has been submitted to its influence, and not less 
 probably has some impression from it been stamped upon us all. It 
 may even be doubted whether now, in our advanced stage of civilization, 
 those who are apparently exempt from all possibility of influence from 
 marsh miasm may not still, in some minor degree, suffer from its remote 
 
106 THE PEDIGREE OF DISEASE. 
 
 effects. It is very possible that, although the severity be far below 
 what is needed to produce an intermittent, yet that the well recognized 
 ill-effects of certain winds quite disproportionate to their chilling power 
 may be due to slight impregnation with malarial poison. As to the 
 diathesis of gout, I have suggested that it is but rarely of pure breed. 
 Very often it builds on the foundations laid by other maladies, and 
 however much it may boast itself the dominus morhorum, morbus 
 dominorum it is, if we can see it aright, very often merely a complica- 
 tion of plebeian rheumatism. Other diatheses have been mentioned 
 which it is difficult to place in any definite arrangement. That in 
 which there is remarkable tendency to haemorrhage I have associated, 
 for the most part, either directly or remotely with the disease of the 
 arterial system induced by gout. That which is characterized by failure 
 of nerve tone I have linked in a like manner — not invariably, but still 
 very commonly — with the infiuence of the sexual system upon the 
 general health. So also of the state characterized by undue mobility 
 of nerve force, or emotional susceptibility, known as hysteria. That 
 there are hereditary diatheses which are characterized by peculiarities in 
 the state of the different viscera, or of specialized systems, has also been 
 suggested. In this category we have the hepatic diathesis, the diathe- 
 sis denoted by chilblains, and that in which the vascular system gener- 
 ally is v«ry feeble; and there results the liability to venous congestion 
 in exposed and distant parts — even to gangrene of the extremities. I 
 made no attempt at completeness in the enumeration of the diatheses, 
 for it is clear that a little ingenuity might subdivide or define them to 
 an almost endless extent. The description of a fresh diatheses is, in fact, 
 almost as easy as the discovery of a new nerve centre, or the revelation 
 of a new bacterium. Let me not be thought to speak in the least 
 slightingly of modern investigations in the two latter directions. I 
 simply couple them with the attempts made to classify morbid phenom- 
 ena, and to say of them all that they are, for the present, tentative, 
 and that the experience of the profession in the future must assign 
 them their real value. 
 
 Finally, I think I may claim in all that I have said as to idiosyncrasy 
 and diathesis, that I have done my best to recognize the power of hered- 
 itary transmission, and to insist that we ought to study disease as 
 
CONCLUDING EEMAEKS. 107 
 
 being, not of recent origin, or in dependence solely upon existing in- 
 fluences, but ratber seek to truthfully " read the record of its long 
 descent. " 
 
 Again I must ask pardon, as I have already once done, for the fact 
 that I have doubtless often appeared to be stating as somewhat novel, 
 things which are well known and almost commonplace. I could not 
 possibly, from the nature of my subject, have avoided this, nor, indeed, 
 have I made much attempt to mark out what I wished to claim as 
 original. It is abundantly sufficient for my ambition if, availing my- 
 self thankfully, so far as my knowledge extended, of the labors of those 
 who have gone before me, I have succeeded in any degree in making 
 opinion more definite, and giving emphasis to that which is true. 
 
II^DEX 
 
 page: 
 
 Acne as a revealing' symptom 85 
 
 Albinism not a cause of temperament 13 
 
 Arsenic, idiosyncrasies in respect to 33 
 
 Arsenical herpes ^ . 34 
 
 Barlow and Lees, on rickets 66 
 
 Bazin, his description of hydroa 39 
 
 Beati possidentes ; 81 
 
 Beddoes, Dr., on British ethnology 103 
 
 Boils, family liability to 50 
 
 Bronchocele, as a symptom of diathesis 58 
 
 Catarrh as a diathesis 96 
 
 " definition and restriction of the term 96 
 
 Catarrhal diseases, laws of . 97 
 
 Carbuncle an erysipelatous boil 51 
 
 Carbuncular inflammation, idiosyncrasy in reference to ... 50 
 
 Chloroform, idiosyncrasies in reference to 37 
 
 Classification should be based on causes 105 
 
 Climate as a cause of diathesis 58 
 
 Complexion, the elements of 15 
 
 " often confused with temperament 5 
 
 Dai'win, differences between black and white sheep .... 14 
 
 Diathesis caused by diet 59 
 
 " the three universal ones 105 
 
 " definition of 55 
 
 " must not be confused with temperament 10 
 
 Diet-diathesis 59 
 
 " idiosyncrasies in respect to 28 
 
 Diphtheria, idiosyncrasy in reference to 49 
 
 " contrasted with erysipelas . 49 
 
 Diphtheritic inflammation often recurrent 79 
 
110 INDEX. 
 
 PAGE 
 
 Dysorasia, cancerous, distinct from diathesis 74 
 
 Drugs, in reference to idiosyncrasy 37 
 
 Bales, Mr., cases of hemorrhage into the eye 102 
 
 Ear, peculiarities in 16 
 
 Eczema as a revealing symptom ........ 87 
 
 " an instance of self-aggravation 77 
 
 " facts as to therapeutics . . 88 
 
 " its relation to gout 88 
 
 Eggs, idiosyncrasy in respect to 38 
 
 Elephantiasis, its relation to erysipelas 80, 83 
 
 Epistaxis, cases of 101 
 
 Ergotism as a food diathesis 67 
 
 Erysipelas, its liability to recurrence 79 
 
 " its allies . . 80 
 
 Erythematous lupus 93 
 
 Fair and dark persons, difference between ...... 13 
 
 Family diseases, examples of 33 
 
 Fish, idiosyncrasies as to 39 
 
 Food diathesis 59 
 
 Fox, Dr. Tilbury, case of lupus lymphaticus 94 
 
 Gangrene oocuring in the exanthemata 43 
 
 Gay, Mr. John, proposal to excise lupus 90 
 
 Gout as a cause of heritable disease of arteries 101 
 
 " complications, inheritance of 101 
 
 " diathesis 60 
 
 Hcemophilia an inheritance from gout ....... 101 
 
 Haemorrhage 101 
 
 Hasmorrhagic diathesis • 101 
 
 " " and haemophilia, their relationship . . . 103 
 
 Harrison, Mr., cases of haemorrhagic diathesis 101 
 
 Hebra's xeroderma, cases of . . 23 
 
 Hulke, Mr., a case of tobacco blindness 33 
 
 Hydroa caused by iodides .... .... 40 
 
 Hypericum poisonous to white sheep' .... . . 14 
 
 Ichthyosis as a family disease . 35 
 
 Idiosyncrasies of function 31 
 
 " not revealed by temperament 17 
 
INDEX. Ill 
 
 PAGE 
 
 Idiosyncrasies as revealing symptoms 83 
 
 " of structure 31 
 
 " revealed wlien tone is defective 39 
 
 Idiosyncrasy 19 
 
 " in respect to drugs 37 
 
 " definition of 3 
 
 Iodide eruptions very various in forms 40 
 
 " a fatal case 40 
 
 " a case mistaken for variola 41 
 
 Iodides and bromides, idiosyncrasies in respect to 37, 38 
 
 Infection, laws of .... 75 
 
 Inflammation, almost all form's of, infective 76 
 
 Inheritance of syphilis, laws of 71 
 
 Iritis as a revealing symptom 95 
 
 Last- joint arthritis as a revealing symptom 95 
 
 Lay cock, Dr., his definition of temperament 4 
 
 ' ' on the need of British, ethnology 4 
 
 " physiognomical diagnosis 9 
 
 " his classification of temperaments 9 
 
 " his observation on the ear 16 
 
 Legge, Dr. Wickham, on haemophilia 101 
 
 Leprosy a food diathesis 61 
 
 " cases of recovery from 62 
 
 " summary of the arguments in respect to fish .... 63 
 
 Life records, importance of 53, 104 
 
 Lower animals, cancer in 74 
 
 Lymphatic lupus 94 
 
 Lupus, a name for a family of diseases 91 
 
 " erythematosus, its relation to chilblains ' 93 
 
 " its nature 89 
 
 " its relation to cancer 89 
 
 " lymphaticus 94 
 
 " necrogenicus 91 
 
 Mackenzie, Dr., on tobacco blindness 31 
 
 Mackenzie, Dr. Stephen, cases of xanthelasma 34 
 
 " " cases of iodide poisoning 43 
 
 Malaria as a cause of diathesis . . 57 
 
 Malignant growths in reference to diathesis 73 
 
 MoUites ossiiun .... 66 
 
1 1 2 INDEX. 
 
 PAQE 
 
 Necrosial fever of Simon T6 
 
 Ormerod, Dr., case of osteo-malachia 
 
 Paget, Sir James, on the treatment of carbuncle 51 
 
 Parker, Mr. Robert, microscopic examination by 94 
 
 Parrot, M., his views as to rickets and syphilis 66 
 
 Pathological habit, laws of 79, 81 
 
 Pellagra a food diathesis 67 
 
 Periostitis, acute, often multiple 76 
 
 Pigmentation, peculiarities in 6 
 
 '■ in animals, differences of 13 
 
 " in reference to liability in disease 14 
 
 Prurigo often merely an idiosyncrasy 48 
 
 " its various exciting causes 48 
 
 Psoriasis, its relation to ichthyosis 37 
 
 " does not occur in infancy 27 
 
 Racial peculiarities often confused with temperament .... 8 
 
 Raymond on symmetrical gangrene of the extremities .... 95 
 
 Retrospective symptoms 83 
 
 Revealing symptoms 82 
 
 Rheumatic fever contrasted with necrosial fever 77 
 
 Rheumatism and gout, their relationship 100 
 
 " and catarrh, their relations 98 
 
 Rickets, the diathesis of 65 
 
 Sangster, Dr., microscopic examination by 94 
 
 Scarlatina, in reference to idiosyncrasy 45 
 
 " narrative of a family outbreak 45 
 
 Scrofula as a diathesis 63 
 
 " in relation to catarrh 98 
 
 Scurvy, a short diathesis 66 
 
 Self-aggravation of morbid processes 75 
 
 Senility as a cause of cancer . . 74 
 
 " as a form of diathesis ......... 74 
 
 Simon, Mr. , on necrosial fever 76 
 
 Solid CEdema a consequence of erysipelas 81 
 
 Southey, Dr., on Raymond's disease ........ 95 
 
 Specific fevers vary in severity with idiosyncrasy 43 
 
 " as possible causes of diathesis 67 
 
INDEX. 
 
 IIH 
 
 Specific fevers minified by idiosyncrasy 
 
 Squire, Mr. Balmanno, cases shown by, to the author 
 
 Startin, Mr. James, cases of xanthelasma 
 
 Stokes, Mr., his case of vaccinia becoming gangrenous 
 
 Syphilis, in reference to idiosyncrasy .... 
 
 " hereditary, laws of 
 
 " as a cause of diathesis 
 
 " second infections 
 
 Syphilitic diathesis not hereditary .... 
 Summary, general 
 
 PAGE 
 
 46 
 
 24 
 44 
 47 
 71 
 67 
 67 
 70 
 104 
 
 Tea, idiosyncrasies as to 29 
 
 Teeth, family peculiarities in 13 
 
 Temperament, clinical importance of 17 
 
 " definition of the term . 2 
 
 " distinction from diathesis 2 
 
 Tetanus, hereditary proclivity to 32 
 
 Tobacco, idiosyncrasy as to ... .... 30 
 
 " amaurosis 31 
 
 Tone, defective, as influencing diathesis 103 
 
 Tophi as revealing- symptoms of gout. 100 
 
 Transmutation in transmission 71 
 
 Treves, Mr., his lecture on scrofula 63 
 
 Universal diatheses 
 
 Varicella varies with idiosyncrasy 
 Variola, in reference to idiosyncrasy 
 Volkmann, his treatment of lupus 
 Vitreous, haemorrhage into 
 
 43 
 
 42 
 
 90 
 
 102 
 
 Watson, Mr. Spencer, on rickets 63 
 
 Wells, Sir Spencer, on generalized gout 100 
 
 Wilks, Dr., on necrogenic lupus 91 
 
 Wordsworth, Ml'., on tobacco blindness 31 
 
 Wormald, Mr., the dark complexion tolerant of mercury .... 13 
 
 Xanthelasma in families, cases of 
 
 " as a retrospective symptom 
 
 24 
 84 
 

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