LETTSOMIAN LECTURES

ON

TROPICAL DYSENTERY AND DIARRHEA.

By Surgeon-General SIR JOSEPH FAYRER, K.C.S.I., M.D., LL.D., F.R.S., Q.H.P.

LECTURE I.-PART II.

I HAVE said enough now, I think, to show that dysentery is almost universal, though more prevalent in certain parts of the earth than in others.

That it is endemic, and often assumes a widely spreading epidemic character, in tropical latitudes, while it is comparatively infrequent and slight in others. It is not confined to the localities referred to in the official reports, but may be met with in Australia, the Americas, South Africa, Egypt, Arabia, the shores and islands of the Mediterranean, the South of Europe, and in fact anywhere, and is capable under certain conditions of becoming epidemic.

It appears to be less severe in hilly countries and above certain elevations; whilst in alluvial plains and valleys, especially where there is malaria, it is more so; and there are certain regions even in the tropics which, from some physical peculiarity of soil or of climate, seem to be exempt.

It is needless to occupy more time in describing the geographical distribution, and I shall now consider the question of causation.

First, let me define dysentery. Dysentery may be defined to be a febrile disease, the result of the action of various noxious influences, or of a specific miasm, on the body under certain predisposing conditions.

Constitutionally it presents pyrexial and nervous phenomena; locally, hyperemia, inflammation, exudation, ulceration or sloughing of the coats of the large bowel, with certain pathological changes in the glandular follicles, in some cases extending into the ileum, accompanied by nausea, tormina, teneamus, scanty but frequent evacuations of gelatinous or sanguineous mucus, of sero-sanguinolent or of muco-purulent matter and blood, mingled with fæces of a peculiar odour; in the later stages, of shreds or masses of slough, sometimes involving large portions of the gut.

It may terminate in resolution and rapid recovery; or pass into inflammation, exudation, ulceration, sloughing, or gangrene, when it is dangerous or rapidly fatal; or it may cause a chronic condition of thickening, ulceration, and cicatricial constriction, which is tedious, and may be ultimately fatal. It may be complicated with other diseases.

Several forms are described-sthenic, asthenic or adynamic, catarrhal, fibrinous, diphtheritic, contagious, noncontagious, sporadic, endemic, epidemic, acute, chronic, malarious, cachectic, hepatic, hæmorrhagic, erysipelatous, sloughing, gangrenous or malignant, typhoid, and so on. These merely express phases or complications of the same disease-process, which always involves some part of the large gut as the seat of the essential local expression of a constitutional disease, true dysentery.

There is a tendency to involve other organs or tissues in the dysenteric process-e.g., the serous membranes, kidneys, lungs, liver, spleen, etc.,-or there may be septic infection by absorption from the diseased intestine. Tropical endemic and epidemic dysentery differs from the sporadic form chiefly in degree; the morbid process is otherwise the same in both. Under certain conditions it would appear to be infective.

ETIOLOGY.

A great variety of opinions have been held as to the cause of dysentery, and many forms of it have been described. For example, Zimmerman recognised the inflammatory, the bilious or putrid, the malignant, and the chronic. Until the time of Willis and Sydenham, ulceration of the intestine was regarded as the essential element of the disease. They, with Pringle and Morgagni, aver that ulceration is VOL. L 1881. No. 1595.

not the gravamen of the disease; that either it does not exist at all, or very slightly.

The disease, said Pringle and Sydenham, is essentially due to acrid humours in the blood. Degner considered that it was due to corrupted bile; Willis, miasmata in the blood; Stoll, in 1789, that it was due to rheumatism of the intestines. The last-named described five species-inflammatory, the summer (which he subdivided into three-the bilious, the putrid, and the malignant), the intermittent, the sporadic, and a fifth, which follows diarrhoea, of which it is only an exaggerated phase; he also added two other forms-complicated (that is, bilious and inflammatory combined); and the seventh, which, with Willis, who observed it in London in 1670, he named serous dysentery. Broussais and Pinel considered it an inflammation, more or less violent, of the large intestines-a colitis, in fact. Such may be taken as examples of some of the views formerly held as to the nature and origin of this disease.

Fouquet, who wrote on Dysentery in 1852, says that it is neither intestinal rheumatism, nor ulceration produced by bile, acrid or putrid discharges, according to the older writers; nor a fever thrown on the intestines, according to Sydenham and his school; nor is it simply colitis; nor an eruption of a pustular character, produced by an acarus, according to others; but that it is a spasmodic disease of a clonic character, whose seat is in the great sympathetic, localised and manifested in the great intestine-an affection in which there is diminished general sensibility, exaltation of the contractile muscular movements of the intestine, and increase of the mucous secretion, and that when the spasms attain a certain intensity and duration, they determine organic lesions of a grave character. He says, moreover, that the indications for treatment founded on this theory are to allay spasm, to restore the normal state of the nerve-centres, and subsequently, the consideration of the intestinal lesions. As to the cause, he says that it is produced by disturbance of innervation in various ways, and, admitting that the causes usually assigned are efficient, they are so by their action on the nerve-centres, and that the same effects may be produced by other and totally different causes. He denies entirely that dysentery is contagious, and says:-"Pour mois je n'ai jamais vu la dysentérie devenir contagieuse, quelle que fût la gravité de l'épidémie je n'ai vu ni les infirmiers, ni les sœurs, ni les médecins la contracter de cette manière. Je ne l'ai vu se répandre par contagion, ni dans les maison particulières, même les plus sales ni dans les hôpitaux les plus encombrés et les plus mal tenus, ni dans les vaissaux où les rapports sont continuels, où les mêmes fournitures sont communes à tous les malades. Si elle s'est répandue d'une manière contagieuse en apparence dans les villes assiégées, dans les camps ou régnait la famine, dans les circonstances exceptionelles; n'est il pas plus rationnel d'en attribuer l'origine et les ravages soit aux aliments de mauvaise nature, soit aux affections morales, soit à d'autres causes."

"Ce qu'il y'a de certain, c'est qu'on ne la contracte pas pour avoir touché le corps ou les habits d'un sujet qui en cet affecte."

"Ainsi non seulement la dysentérie n'est pas contagieuse; mais il n'est pas encore certain qu'elle puisse se transmettre d'une manière quelconque d'un sujet à un autre.”

"Mais quand nous admettrions avec les contagionistes que les émanations des selles des dysentériques produisent la dysentérie; quand nous croirons avec Desgenettes et avec Vignes que les miasmes dégagés des substances animales en putréfaction la développent; quand nous reconnaitrons avec Zimmerman que le flair d'un sang corrumpu dans une bouteille la fait naître ; ne savons nous pas que l'action des miasmes s'exerce principalement sur le système nerveux de la vie organique. Les émanations animales peuvent produire des spasmes; et si leur action est trop forte ou longtemps continuée, donner lieu au typhus, maladie ou les désordres nerveux sont en même temps si variés et si profonds, ou l'on observe tantôt un aneantissement, tantôt une exaltation partielle de cette innervation, et toujours un trouble grave dans le système nerveux cérébrospinal et dans les nerfs ganglionnaires. La fièvre intermittente dont le foyer est dans le système nerveux, n'est elle pas produite par un empoisonnement miasmatique ? Tous les miasmes dégagés des substances en putréfactions sont

des agents essentiellements perturbateurs des système nerveux, dont ils tuent la vitalité, ou dont ils sollicétent les plus violentes réactions. Les odeurs seules, lorsqu'elles sont fortes et concentrées, peuvent causer des spasmes ou les faire cesser."

And so he ascribes the origin to the operation of these causes on the nervous system. He explains the lesions that sooner or later occur in the bowels as a consequence of the spasmodic condition of the bowels, and not as its cause; and he dwells on certain anatomical and physiological reasons, as seen in the muscular arrangements of the sphincter, the upper part of the rectum, and in the ileo-colic valve. He says the ulcerations and diseased intestinal glands are no essential part of the disease, and points to the undoubted fact that in many severe and fatal cases no ulceration is found. These views, which are peculiar, are most worthy of consideration, though they do not altogether coincide with those of other pathologists who regard the morbid condition of the glands and mucous membrane as essential characteristics of the disease.

Its prevalence and severity in warm countries, where malaria, climate, food and water, are instrumental in causing other diseases, seem to point a similar origin. That there is something in tropical climates favourable to the development of dysentery, appears from such facts as I have related. The degree of severity and prevalence in different regions would point to local conditions as factors in its production, whilst its occurrence in cold climates would indicate that the specific or exciting cause may depend on something independent of heat or malaria.

Dr. Maclean says, It appears that many of the so-called 'causes' of dysentery must be regarded more as acute agents of propagation than of causation." "I believe dysentery to be caused by the action on the blood of a poison having a peculiar affinity for the glandular structures of the large intestine. The poison I believe to be a malaria generated in the soil by the decomposition of organic matter," and "just in proportion as we have banished malaria, so have we got rid of dysentery. For a long time the prisoners in Millbank were subject to visitations of dysentery at those seasons and in those states of atmosphere which most favour the decomposition of organic matter in the soil"-but, it should be added that its disappearance was coincident also with amended diet. The same may be said of England generally, for when malarial fevers prevailed dysentery was severe and frequent. Both have diminished in severity and frequency, and now when seen they are so mild as to show that the activity of the cause has been reduced to a minimum. We are still ignorant of the nature of malaria, though the researches of Tommasi, Klebs, and others are tending to show that it may be due to no miasm at all, but to an organism, a microphyte, developed in the soil, and found there, and in the lower strata of the atmosphere in certain localities and climates, which infects the blood, and being inoculated, causes a paroxysm of ague. We are ignorant also of the nature of the specific poison, if indeed there be one, that causes dysentery. But we know something of the active agents of propagation, and the circumstances under which it is likely to arise; and that it is apt to be prevalent and severe wherever heat, moisture, and alternations of temperature are great, and where there is organic matter decomposing in a damp alluvial soil like that of Bengal. But we cannot assert that it is altogether due to such physical conditions, for there are examples of malarial fevers and dysentery abounding in regions having quite an opposite character, and many outbreaks in camps or other collections of men under depressing conditions, but not in warm climates, such as the armies of England and France in the Crimea during the bleak and inclement winter of 1854, where, as Kinglake says: -"Worn down by hard toil, numbed and lowered by cold and heat, suffering under wants so pernicious as to be too surely followed by scurvy, and assailed too by cholerine, by true cholera, by dysentery, by fevers, and by numberless other complaints, our Army underwent day by day appalling deductions from strength" ("Invasion of Crimea," Kinglake, vol. vi., page 201), prove that the group of symptoms called dysentery may arise under many and varying conditions. It would appear that just as sanitary progress elsewhere has diminished its endemic severity, so it is tending to do the same in India, and there can be little doubt that local outbreaks are greatly under the control of preventive sani

tation. Dr. Coates, Sanitary Commissioner, in his report on Calcutta for 1877, says: "It is worthy of note how rapidly and decidedly dysentery, and indeed all chylopoietic disorders, have ceased to attack Europeans in this country. The old reckless exposure to sun and rain, the heavy tiffins, midnight suppers, and stronger liquor drinking have ceased in proportion. Agues are getting rarer every day." And it might be added that sanitary reports show its tendency to decrease under the operation of sanitary laws. Still the evening and morning damp and chills and sudden alternations of temperature of July, August, September, and the extreme cold night air and heavy dews of October, November, and December, acting on the poor, ill and insufficiently clad, badly fed population, who sleep on damp floors, and of whom a large proportion are broken-down in constitution, subject them in very large numbers to the influence and fatality of bowel complaints. Children and the aged are also very liable to succumb, especially to diarrhoea. Malaria, errors of diet, and bad water help materially to encourage these diseases." Dr. F. N. Macnamara, in his "Diseases in Himalayan India," page 129, says :-" Bowel complaints, mainly dysentery and diarrhoea, stand next [to fevers] as causes of mortality amongst the people. The group probably includes, on the one hand, many cases which ought to be recorded as cholera, and on the other, many which would more directly have been attributed to fever complicated with diarrhoea or dysentery. Malaria, exposure, unwholesome food, such as unripe fruit and new rice, and, above all, foul water, are active causes of this group of diseases." And many other observers have recorded similar opinions.

In the Native Lunatic Asylum of Calcutta, where up to 1876 the inmates suffered much from dysentery, diarrhoea, and lumbrici, Dr. Payne discovered that "the patients were in the habit of drinking water placed in reservoirs outside the latrines for purposes of ablution. They washed and then took a mouthful of water. On putting a stop to this practice the disease almost disappeared from the Asylum."

In those regions that lie within the tropics or subtropical parallels, the heat and moisture, acting on organic matter, seem in some way to favour the development of the cause, and no doubt tend also to predispose the individual to become receptive of it. But none of these are sufficient of themselves to cause it, for dysentery does not invariably result when they are present, and there are regions in India, Africa, and elsewhere where it is all but unknown, albeit the conditions usually supposed to determine its prevalence exist abundantly. There are others, apparently not more unfavourable, where it is excessively severe; whilst it appears sporadically in northern climates, and has even raged as a dangerous epidemic-showing that the cause may arise anywhere under certain influences which apparently are always existent in some parts of the world, occasionally only in others. But however dysentery may arise, there seems to be no difference in its anatomicopathological characters, except in so far as these may be modified by malarial or other complications.

Twining, Annesley, Chevers, and many others have pointed out the efficiency of impure water as a cause. (a) I have referred to an instance of it given by Dr. Payne in Calcutta; and the diminution of dysentery and diarrhoea among the inhabitants of Calcutta and the sailors of the shipping in that port which is said to have taken place since the introduction of an improved water-supply replacing the tank- and unfiltered rain-water, if it be the case, confirms the probability of this view.(b)

(a) Dr. de Renzy, Sanitary Commissioner, Assam, says:-" On a large tea-garden in Sibsagor district I found, on examination of the hospital books, that not only had the death-rate been reduced to less than half, but the daily sick had been reduced from ninety to forty. Similar results were obtained on a large garden in the Darrang district; the number of cases of dysentery had immediately decreased, with a corresponding saving of life, and-a very notable fact-cases of worms had become comparatively rare." This was the result of furnishing good water in lieu of that they had been drinking. This improved water had been procured from wells deeply sunk and lined with earthenware glazed pipes, instead of the surface water contaminated with filth from the villages and other sources of impurity.

(b) I am indebted to Mr. Charles Buckland, C.S., for the following information respecting the number of sailors entering or discharged from the port of Calcutta (average of three years, 1878-80):-Total Europeans, 4040 shipped, 3900 discharged. Total natives and other nationalities (viz., West Indian negroes, South Sea Islanders, Sandwich Islanders), 15,174 shipped, 13,552 discharged. The improvement in health in the above large floating population is, I am told, well marked since the introduction of better drinking-water. The precise number of cases of dysentery and diarrhoea I have not been able to obtain, but am informed that they have diminished considerably.

Unwholesome food, defective in quantity or quality, in the scorbutic form of the disease especially, is an important factor. Bad fermenting grain; unripe acid fruits; irritating drugs or articles of diet of any kind; excessive use of salt provisions; rancid or decomposing matters, especially fatty and albuminous articles; intemperance in alcoholic drinks, especially bad sour wines, impure spirits, and malt liquors, which irritate and cause diarrhoea, that is apt to pass into dysentery in localities where the disease is endemic.

Vicissitudes of climate, exposure to cold and heat, sudden alternations of temperature, such as occur at the setting-in of the cold season in India, or when the transition from the heat of the day to the cold of night is intense; exposure to cold damp winds, and the ill effects of the moisture of the rainy and the drying-up season in September and October, when the air is loaded with watery vapour; exposure of the body, especially the abdomen, during sleep or when perspiring; the sudden laying aside of flannel body-clothes, and so on,-such proceedings being always pregnant with danger in a malarious or dysenteric region; even excessive dryness of the atmosphere, according to Mouat,-are effective adjuncts of the specific cause.

Pringle (page 19 of his "Observations on Diseases of the Army") gives some remarkable instances, which it would be easy to parallel by others of more recent occurrence, such, for example, as that in H.M.S. London, at Zanzibar, in 1878. He says::-"On June 26, 1743, in the evening the tents were struck, the army marched all night, and next morning fought at Dettingen. On the night following the soldiers lay on the field of battle without tents, exposed to heavy rain. Next day we moved and encamped on good ground in an open field, but it was wet (for two nights), and the first night or two the men wanted straw. By these accidents a sudden change was made in the health of the army; for the summer had begun early and the weather had become constantly warm; now the pores were suddenly stopped, the body was chilled, and the humours tending to resolution from the preceding heats were turned upon the bowels, and produced a dysentery which continued a considerable part of the campaign. In eight days after the battle about 500 men were seized with that distemper, and in a few weeks nearly half the men were ill or had recovered." Trotter in his "Medica Nautica " (vol. i., page 878) mentions "a lamentable dysentery" which was produced on board H.M.S. Berwick, in October, 1780, in consequence of the hurricane on the 5th of the month, by which the clothes and bedding of the seamen, and indeed every part of the ship, were soaked in water, and many of the men "slept for nights together on the wet decks, overcome with fatigue and debilitated from the want of food." In seven weeks thirty of the best men died of dysentery, in some cases complicated with scurvy, and near 300 of the ship's company were ill when she arrived at Spithead. But, remarks Bancroft, "Dr. Moseley says, 'it has often happened that hundreds of men in a camp have been seized with the dysentery almost at the same time, after one shower of rain, or from lying one night in the wet and cold' (see his treatise on Tropical Climates, third edition, page 265). I suspect, however, that in such cases the disease is not exactly like that which principally results from marsh effluvia; that it has a greater similitude to diarrhoea, and if accompanied with fever, that this is nearly related to that of catarrh." Bancroft evidently did not believe that dysentery was always produced by a specific poison, but was the result of a catarrhal condition manifesting itself in the large intestine; and it is not improbable that such is the explanation of some cases of sporadic dysentery, and that the cause, whatever it be, is the result of changes depending on external influences, such as chill and damp, thus justifying the distinction drawn by some authorities between the endemic or epidemic dysentery of tropical climates, and the sporadic cases of milder type that occur in any part of the world. That symptoms resembling dysentery do occur, even in India, is well known to those who have studied children's diseases there, when what appears to be dysentery in a child disappears on the free lancing of swollen gums during dentition and the administration of a little grey powder; whilst, in the course of other diseases, symptoms may supervene as a consequence of fever and various forms of blood-poisoning, difficult to say in what respect they differed from real dysentery. Does dysentery depend on a specific poison introduced into the system, or is it the result of a combination of several evil influences ? That something is superadded in the case of malarious and

tropical or other epidemic dysentery seems probable. That something must be the miasma of Maclean and others; it may be a microphyte, like that of Klebs and Tommasi, etc.; but until we are able to demonstrate the poison of typhoid fever, malarial fever, dengue, and the like, this too must remain a matter of speculation. The fact is, we have yet much to learn, and it may be that Fouquet is right, as I am inclined to believe that in a measure he is.

Impure air from any cause, but especially from putrefying organic matters, vapours from drains, cesspools, bilges of vessels, latrines and reservoirs of stagnant water, putrescent with animal or vegetable matter, or it may be infected with microphyte germs, the emanations from ground that has been recently disturbed, and from which vegetation has been recently removed, from swampy, malarious, and mephitic pools, whence fever, cholera, typhoid, and other evils are said to be derived, may become the predisposing if not the exciting causes of dysentery. Which particular element in these emanations dispose to dysentery, which to fever, it would be hard to say; that they do so, however, we must conclude from the evidence. And there are instances on record of dysentery of a severe and deadly type having supervened after exposure to such effluvia. I remember one, in the case of a detachment of European soldiers sent, during the last Burmese war (1853), to occupy an outpost near Martaban, on ground that had recently been cleared of dense tree-jungle, possibly with the view of making it healthier. That the men would contract ague or remittent was only too probable. However, there were few fever cases, whilst many suffered from dysentery, which proved rapidly fatal from gangrene affecting the whole or greater part of the large intestine. These I regard as marked examples of the worst form of malarious dysentery. Instances of persons suffering from dysentery after exposure to the foul air of latrines, bilge-water, and the like, are recorded by Fonssagrives, McGregor, D'Arcot, and other writers. But of all effluvia none are said to be more noxious than those given off from the dejecta of persons suffering from the disease, especially when crowded in hospitals. Whether this is due to direct infection, intensified by concentration, or to general depressing effects, causing a condition of blood-poisoning, as other putrid organic evacuations are said to act, I know not. There is reason to believe that in such cases the disease is apt to spread, and that epidemics are thus diffused. If it be true that it is infective when arising from sporadic cases, it would appear that dysentery is capable of being originated de novo. That such effluvia are capable of contaminating the atmosphere I have myself had proof. In hospitals where sloughing and gangrenous cases of dysentery were treated under the same roof, if not actually in the same ward, wounds and surgical operations assumed an unfavourable action, or septicemia in some form, or dysentery itself, supervened.

Fergusson, who had large experience, says:-"True dysentery is the offspring of heat and moisture, of moist cold in any shape after excessive heat, but nothing that a man could put into him would ever give him true dysentery." That an ordinary case of sporadic dysentery is free from danger to those who come in contact with it, I believe ; but the case may be different where the patients are numerous in a ward, especially if strict precautions as to removal of discharges are not observed. When certain local and climatic conditions exist, and a certain epidemic constitution prevails, the disease may from such a focus become epidemic and highly infective, though how I am not prepared to say. It has also been attributed to infection by fæcal contamination, just as many regard cholera and typhoid fever to be the direct result of a poison generated in the alvine secretions, or developed in the form of microphyte in the dejecta of human beings, and so conveyed to others, and thus spreading as an epidemic. Indeed, one anonymous writer, whose views are as remarkable for their force as for their originality, attributes it solely to this cause, and says, " If human excrement be not exposed to the air there can be no dysentery." The fact is, we do not know how it originates, though we do know that under certain conditions it will appear that it is amenable to sanitary laws, and to a great extent preventable or mitigable. Great stress is laid by some on malaria as a cause, and the malarious dysentery is even regarded by them as a specific form of the disease, whether received from air or water saturated with the malarial poison; but I do not know that there is any other difference than one of degree,

or such as might naturally result in an individual depressed by malarial cachexia.

Mechanical irritation is also a recognised predisposing cause; irregular action of the bowels, constipation, and the accumulation of scybala in the cells of the large intestine, which may have been in a state of catarrhal disturbance; or where any temporary obstruction may have taken place, vitiated bile, or any other acrid alvine secretion may be present. The form of dysentery called" hepatic " by Annesley was connected by him with disordered liver, and bile and intestinal secretion depending thereon setting up inflammation and dysenteric mischief in the colon.

In fact, the line between a catarrhal disturbance of the bowel and a case of dysentery is not definitely drawn. I am not aware that individual peculiarities are of any special importance. The disease may attack anyone and at any age. Malariously cachectic and delicate persons, and those who are suffering from other diseases, wounds, or accidents, are liable to suffer. Men, from greater exposure and the duties peculiar to the occupations of their sex, are more liable than women, who have been thought by some to enjoy a certain immunity owing to the relief of tendency to congestion in the pelvic viscera conferred by the regular recurrence of the catamenia. Congestion of the abdominal viscera and of the portal system, especially in debilitated conditions after disease or injury, are also among the conditions favourable to the development of the disease. We are, in short, not yet in a position to say with certainty what is the specific or direct exciting cause of dysentery, whether it be a malarial poison, a microphyte, a gaseous emanation, a miasm, or some influence acting dynamically through the

nerve-centres.

In the present state of our knowledge we can only say that under certain conditions and influences it may be expected to arise, and that happily we are able, by the aid of sanitary laws, to moderate its prevalence, and by therapeutics to mitigate its severity. We may hope that the rapid progress now being made in the investigation of the causation of diseases will ere long throw light on what still is obscure.

SYMPTOMATOLOGY.

Dysentery generally commences with simple diarrhoea, probably accompanied or preceded by very little derangement of the general health. This may be of one or two days' or of longer duration. The evacuations are not at first attended with uneasiness or pain-indeed, they give temporary relief,- but as the disease advances, the desire to empty the bowel becomes more urgent, and is accompanied by tormina and tenesmus, the dejecta consisting chiefly of gelatinous mucus. Little relief is now afforded by the act, which is rapidly repeated, whilst with each effort the fæculent character is diminished, until at length rosy gelatinous mucus, sero-sanguinolent fluid, or blood is discharged. Griping is severe, and there is pain on pressure over the tumid abdomen. The dejecta have an offensive and characteristic odour. The general symptoms are more or less marked, according to circumstances and the peculiarities of the case. There is lassitude, nausea or sickness, loss of appetite, and a pinched and sallow expression of countenance; yet in some cases the disease may have advanced from the state of diarrhoea, perhaps preceded by constipation, into well-marked dysentery before the patient recognises the real nature of his complaint, takes alarm, or desists from his ordinary avocations. The symptoms are more pronounced in the young and previously healthy than in those who have resided long in the climate, have suffered from previous disease or malarial cachexia. There may be, perhaps generally is, a certain amount of febrile disturbance, a slight rise in temperature, preceded by chilliness, sometimes a rigor, and general discomfort; but as in malarious regions fever is often present, it is difficult to say how far they may be due to this cause. As regards temperature, there is nothing that can be called typical of dysentery alone; the rise probably depends on periodic fever, though it may be due to the dysentery. The calls to stool are most frequent and severe at night; there is a sense of fulness and burning pain in the rectum, as though some foreign body were there, which is very distressing; and pain extends over the whole abdominal surface, more severe over one part of the colon than another; whilst the constant efforts to defæcate, which are so urgent that the patient will hardly leave the stool, and which may extend

to the bladder, cause strangury, great exhaustion, and nervous depression. Such is the condition in the catarrhal or congestive stage, and it is of the greatest importance that it should be dealt with at this period, for it may now be arrested and recovery rapidly take place. Indeed, acute dysentery, in previously healthy persons, if dealt with early, before the bowel has passed beyond the stage of catarrhal congestion, is most amenable to treatment, and need cause little or no anxiety to anyone. This condition may last for some days, and does not always readily yield to treatment; during its progress the patient is much worn and exhausted by suffering. Exacerbation takes place during nights, which are disturbed by constant suffering. He rapidly becomes emaciated; his tongue is coated and white; the heart's action varies according to strength, and is often feeble. When the disease progresses, either in the absence of due care and treatment, or from a natural tendency to get worse, as in the epidemic form, the symptoms become intensified. The evacuations are passed with increasing tenesmus, and become more bloody, serous, or mucous, mixed with decomposing blood and fæcal matter. The tongue now becomes dry and red, in some cases affected by aphthous ulceration, or loaded with a coating of epithelium, which renders it white and swollen. Shreds of sloughy tissue begin to appear in the discharges, which are passed with intense straining. The abdomen becomes more tender, the thickened gut can be felt through its walls, the strength fails, the face becomes pinched and sunken, the skin harsh, dry, and yellow, the voice depressed, whilst the patient presents all the appearance of great exhaustion, and, sinking lower and lower, death from cardiac asthenia may result. But the changes in the gut may progress rapidly; other organs may be involved, and the mischief spread to the peritoneum; peritonitis or perforation may occur, and cause rapid death; or in the ulcerative process, vessels may give way, and copious hæmorrhage carry off the patient; or gangrene may set in, when he falls rapidly into a state of collapse, indicated by cold clammy sweat, eyes sunken, voice husky, absence of pain, thready rapid pulse, body and limbs cold, dark-coloured foetid involuntary motions, muscular spasms, and death.

It is necessary to watch the appearance of the discharges, as pointed out by Dr. Goodeve, by carefully washing them and allowing the different parts to separate. The sloughs are thus distinguished from fæces, mucus, or other matters; the state of the bowel, the stage of the disease, and the nature of the morbid process may be ascertained with much accuracy. Branny mucus, sloughs of various sizes, from small shreds to pieces the size of from a threepenny-piece, sixpence, to half-a-crown, or larger, sometimes tubular portions, may be detected, and consist either of the exudation or of the mucous membrane itself. Though recovery is often complete, it is not always so, and structural changes in the bowel give rise to serious chronic disease, the symptoms continue, or after temporary amelioration they The dejections may become less bloody, but there is a chronic diarrhoea of loose fæculence mingled with blood, mucus, muco-purulent matter, or pure pus. The rectum is in a state of extreme irritability: there may be protrusion, or the anus is excoriated, and hæmorrhoidal excrescences form. The tenesmus and tormina are distressing in proportion to the part of the large intestine affected, most so when the rectum is involved. This chronic dysentery is most exhausting, and completely breaks down the health and strength of the sufferer. It is a frequent source of invaliding, forms indeed a considerable portion of the cases of chronic disease with which old residents in India are affected, and is very prone to pass into chronic wasting diarrhoea of which I shall have more to say in my third lecture.

recur.

Such are the characteristic symptoms; they are modified according to the type or form the disease assumes, or by accompanying ailments.

Various types and forms of dysentery have been described, e.g., the sthenic and asthenic, under which every phase of the disease may be placed. The acute or inflammatory, attacking the young and vigorous, whether it be sporadic or epidemic, is sthenic; the sloughing, scorbutic, malarious, hepatic, and chronic, with continued diarrhoea and ulcerated or thickened bowel, are asthenic. Virchow divided it into the catarrhal or sero-purulent, and the diphtheritic or fibrinous, many cases partaking, at one or other

stage of their progress, of both conditions. These he considered to have each their peculiar course and termination, but that every case is catarrhal at the outset.

In speaking of its pathology, I shall endeavour to illustrate the most characteristic pathological conditions of dysentery by clinical histories of recent cases, and by morbid specimens.

No line of separation really differentiates one type from another, but there are characters sufficiently well marked to distinguish them practically. The acute form, whether it be sporadic or epidemic, presents generally the symptoms I have described, more or less severe, according to the circumstances of the case and the peculiarities of the individual. The symptoms that characterise the malignant or gangrenous, and also the chronic forms, have been referred to.

Malarious dysentery is that in which the patient suffers from the effects of malarial poisoning, and the ordinary symptoms of remittent intermittent are superadded; where there are also complications involving the liver, spleen, or other abdominal viscera, portal congestion, anæmia, gastric irritability, or functional derangement of the abdominal viscera. Under severe impressions of the malarial poisoning (as in the case referred to in Burmah), sloughing, phlegmonous, or erysipelatous dysentery may set in, proving most dangerous, often fatal, death being preceded by great depression and collapse. Again, when the disease becomes epidemic among crowded troops in the field or garrison, especially when the circumstances are depressing and unfavourable, as from defeat or overwork, bad or defective food, and where there is want of proper rest and shelter, the condition may become most deplorable, especially if to the camp-dysentery be added scurvy, scorbutic cachexia, anæmia, dyspnoea, lassitude, exudation into the areolar tissue, pain in the limbs, petechiæ, lividity following the slightest bruise, bleeding and sloughing gums, and foetor of breath, with great general exhaustion; and, added to these, ulceration in the great intestine, attended by hæmorrhage, makes the condition an exceedingly sad one, and, though not so fatal as the malignant or gangrenous colitis, causes great mortality, though, should more favourable circumstances arise-by which I mean improvement in the moral and physical condition of the men, the supply of better food, and prompt and careful treatment of all who present any indications of scorbutic taint-much alleviation is possible, and many lives may be saved. I saw such conditions among the beleagured garrison of the Lucknow Residency. Perhaps nothing, unless it be the gangrenous form of the disease, gives a more striking illustration of destruction of the vital powers and disintegration of the living tissues.

The cause that excites the dysenteric process in the glands of the large intestine seems to act also on the liver. Dr. Budd was of opinion that liver-abscess, when complicated with dysentery, was due to infection of the portal blood by the intestinal disease, and in some instances it may be so, especially when (as in the examples I shall relate) the abscesses are multiple. Such are really typical cases of pyæmia. And I would here remark that these so-called abscesses should rather be regarded as necrosis than as ordinary abscesses, for if they be examined in their earlier stages it will be found that they are patches of dead tissue, which, if life had been prolonged, would have been converted into abscesses by suppuration taking place around the dead tissue, which, acting as a foreign body, provokes the suppuration. Liver-abscess with dysentery sometimes assumes this form, and may be due to direct absorption from the bowel, or to systemic poisoning, as in other cases of pyæmia. This is by no means confined to the liver, for the spleen, the kidneys, or the lungs, and pleural or abdominal cavities, may be affected, and sero-puriform effusions may be found in the cavities.

The researches of Martin, Macpherson, Morehead, Moore, Parkes, Marshall, and others, show that hepatic disease is an occasional complication of dysentery in India and other malarious countries.

Dr. Parkes says that "analysis of the secretion of the liver shows that it is more or less affected in every case of dysentery. Abscess, as a complication, is not the most frequent in tropical dysentery. Baly did not find it in any of the Millbank cases, neither did Rokitansky in his experience; Dr. Wilson found it rare in the dysentery of

China; Cheyne found it in the dysentery in Ireland in 1818 in four cases out of thirty; but Martin says it was observed in the dysentery of the Peninsular War, whilst it was rare in that of the Crimea. The fact is that the liver-disease is often independent of the bowel-ulceration, though due to the same cause, and it would be impossible to predict, if a number of men were exposed to malarial tropical influences, how many would suffer from dysentery alone, from remittent fever, from abscess or other liver-disease, or how many from a disease composed of all these morbid states.

Albuminuria is not a frequent accompaniment of dysentery, but it does occur, and in malarious cases probably more frequently than in others. Its import is always serious, indicating congestion, and tubes or cells loaded with exudation; but I am inclined to think that slight albuminuria is not always of so grave a nature as may be supposed. The spleen also may be involved; and in the ordinary form of enlargement so common in malarious poisoning, which is always productive of anæmia and cachexia, if dysentery supervene, it must obviously be more dangerous, where the tendency to ulceration and disintegration of tissue and hæmorrhage is so great as it is in this state.

But the spleen may be affected also by the cause of dysentery, and become the seat of embolism and abscess or of softening. The lungs, directly affected by the dysenteric process or by septic absorption, may become the seat of lobular pneumonia, embolisms, and local deaths, which end in abscesses. The special symptoms of these conditions would, of course, be superadded to those of dysentery, and ・ would render the prognosis more doubtful.

It is not always easy to distinguish hepatic complications from those of an inflamed and ulcerated transverse colon; but the general concurrence of symptoms such as rigors, sweats, the rise and fall of temperature, indications of pyæmia, and in large single abscess, which may take place insidiously, and with little pain or disturbance of temperature, the physical signs of increase of size, bulging, would aid diagnosis. The danger, of course, in all such cases is great. It is to be remembered that the liver during dysentery or any other disease, or even in health, is more prone to be affected in the tropics than in cold climates, and this may help to account for the cases in which dysentery and liver

abscess are co-existent.

Martin and others thought that liver-abscess was intimately connected with disease of the cæcum, but this is not confirmed by post-mortem examinations, for out of seventy-two cases where the cæcum was affected, in only twenty-two was there liver-abscess.

Moore, in Annals of Military Medicine, says that eight observers out of twelve recorded a percentage of 18 per cent., or 295 cases of liver-abscess in 1532 cases; other four give a ratio of 39 per cent., or fifty-two cases of abscess out of 131 cases of dysentery. Eighteen per cent. is probably the correct ratio; the large percentage is more likely due to all diseased conditions of the liver that have accompanied dysentery.

Recent observations, I think, confirm this view of the relative frequency of hepatic abscess in connexion with dysentery; and though in some instances of multiple abscess the condition is due to septic absorption, yet liver-abscess must be regarded generally rather as an expression of the general disease than as consecutive to the dysenteric ulceration of the large intestine.

It would appear, then, that in different climates, localities, and epidemics it is more or less frequent according to circumstances, but that there is a greater tendency to it in India than in other climates. In malarious countries, liverabscesses frequently occur in association with remittent fever without any ulceration of the bowel (Morehead). Macpherson gives the comparative frequency of liver-abscess in dysentery as varying from 13 per cent. in the General Hospital, Calcutta, to that of nearly 60 per cent. (according to Annesley) as occurring in Madras. Perforation occurred in 11.7 per cent., and extension of mischief to the ileum in 13.2 per cent. (Moore).

A few words on the significance of the symptoms I have described. The tormina and tenesmus are due to irregular and excessive spasm or peristaltic action in the different regions of the colon and rectum, and especially to spasmodic contraction of the sphincter and upper circular fibres of the rectum and ileo-colic valve. They vary in extent and degree according to the part of the gut affected. Spasm in the