cation of any of the stimulant matter, we learn from hence that the passions of the mind do in some persons excite diarrhoea.

1474.] That diseases in other parts may in like mauner affect the intestines, appears from the dentition of infants frequently exciting diarrhoea. I believe that the gout often affords another instance of the same kind; and probably there are others also, though not well ascertained.

1475.] The stimuli (1472.) which may be applied to the intestines are of very various kinds; and are either, 1. Matters introduced by the mouth.

2. Matters poured into the intestines by the several excretories opening into them.

3. Matters poured from certain preternatural openings made into them in certain diseases.

1476.] Of those (1475, 1.) introduced by the mouth, the first to be mentioned are the aliments commonly taken in. Too great a quantity of these taken in, often prevents their due digestion in the stomach; and by being thus sent in their crude, and probably acrid, state to the intestines, they frequently excite diarrhoea.

The same aliments, though in proper quantity, yet having too great a proportion, as frequently happens, of saline or saccharine matter along with them, prove stimulant to the intestines, and excite diarrhoea.

But our aliments prove especially the causes of diarrhoea, according as they, from their own nature, or from the weakness of the stomach, are disposed to undergo an undue degree of fermentation there, and thereby become stimulant to the intestines. Thus acescent aliments are ready to produce diarrhoea; but whether from their having any directly purgative quality, or only as mixed in an over proportion with the bile, is not well determined.

1477.] Not only the acescent, but also the putrescent disposition of the aliments, seems to occasion a diarrhoea and it appears that even the effluvia of putrid bodies, taken in any way in large quantity, have the same effect.

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Are oils or fats, taken in as part of our aliments, ever the cause of diarrhea? and if so, in what manner do they operate ?*

1478.] The other matters introduced by the mouth, which may be causes of diarrhoea, are those thrown in either as medicines, or poisons that have the faculty of stimulat

*Rancid oils and fats certainly irritate the intestines, and inay therefore produce diarrhea.

ing the alimentary canal. Thus, in the list of the Materia Medica, we have a long catalogue of those named purgatives; and in the list of poisons, we have many possessed of the same quality. The former, given in a certain quantity, occasion a temporary diarrhoea; and given in very large doses, may occasion it in excess, and continue it longer than usual, producing that species of diarrhoea named a Hypercatharsis.

1479.] The matters (1475, 2.) poured into the cavity of the intestines from the excretories opening into them, and which may occasion diarrhoea, are either those from the pancreatic or biliary duct, or those from the excretories in the coats of the intestines themselves.

1480.] What changes may happen in the pancreatic juice I do not exactly know; but I suppose that an acrid fluid may issue from the pancreas, even while still entire in its structure; but more especially when it is in a suppurated, scirrhous, or cancerous state, that a very acrid matter may be poured out by the pancreatic duct, and occasion diarrhoea,

1481.] We know well, that from the biliary duct the bile may be poured out in greater quantity than usual: and there is little doubt of its being also sometimes poured out of a more than ordinary acrid quality. It is very probable, that in both ways the bile is frequently a cause of diarrhoea.

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Though I have said above that diarrhoea may be commonly distinguished from cholera, I must admit here, that as the causes producing that state of the bile which оссаsions cholera, may occur in all the different possible degrees of force, so as, on one occasion, to produce the most violent and distinctly marked cholera; but, upon another, to produce only the gentlest diarrhoea which, however, will be the same disease, only varying in degree: so I think it probable, that in warm climates, and in warm seasons, a diarrhea biliosa of this kind may frequently occur, not to be always certainly distinguished from cholera.

However this may be, it is sufficiently probable, that, in some cases, the bile, without having been acted upon by the heat of the climate or season, may be redundant and acrid, and prove therefore a particular cause of diarrhoea.

1482.] Beside bile from the several causes and in the conditions mentioned, the biliary duct may pour out pus, or other matter from abscesses in the liver, which may be the cause of diarrhoea.

Practical writers take notice of a diarrhoea wherein a thin

and bloody liquid is discharged; which they suppose to have proceeded from the liver, and have therefore given the disease the name of Hepatirrhoea but we have not met with any instance of this kind; and therefore cannot properly say any thing concerning it.

1483.] A second set of excretories, from which matter is poured into the cavity of the intestines, are those from the coats of the intestines themselves; and are either the exha lants proceeding directly from the extremities of arteries, or the excretories from the mucous follicles: and both these sources occur in prodigious number over the internal surface of the whole intestinal canal. It is probable that it is chiefly the effusion from these sources which, in most instances, gives the matter of the liquid stools occurring in diarrhea.

1484.] The matter from both sources may be poured out in larger quantity than usual, merely by the increased action of the intestines, whether that be excited by the passions of the mind (1473.) by diseases in other parts of the system (1472, 1.) or by the various stimulants mentioned 1476, and following; or the quantity of matter poured out may be increased, not so much by the increased action of the intestines, as by an increased afflux of fluids from other parts of the system.

Thus, cold applied to the surface of the body, and suppressing perspiration, may determine a greater quantity of fluids to the intestines.

Thus, in the ischuria renalis, the urine taken into the blood-vessels is sometimes determined to pass off again by the intestines.

In like manner, pus or serum may be absorbed from the cavities in which they have been stagnant, and be again poured out into the intestines, as frequently happens, in particular with respect to the water of dropsies.

1485.] It is to be observed here, that a diarrhoea may be excited not only by a copious afflux of fluids from other parts of the system, but likewise by the mere determination of various acrid matters from the mass of blood into the cavity of the intestines. Thus it is supposed that the morbific matter of fevers is sometimes thrown out into the cavity of the intestines, and gives a critical diarrhoea and whether I do or do not admit the doctrine of critical evacuations, I think it is probable that the morbific matter of the exanthe

mata is frequently thrown upon the intestines, and occa sions diarrhoea.

1486.] It is to me further probable, that the putrescent matter diffused over the mass of blood in putrid diseases, is frequently poured out by the exhalants into the intestines, and proves there the cause, at least in part, of the diarrhoea so commonly attending these diseases.

1487.] Upon this subject of the matters poured into the cavity of the intestines, I have chiefly considered them as poured out in unusual quantity, but it is probable that, for the most part, they are also changed in their quality, and become of a more acrid and stimulant nature; upon which account especially it is that they excite, or at least increase a diarrhoea.

1488.] How far, and in what manner, the exhalant fluid may be changed in its nature and quality, we do not certainly know; but with respect to the fluid from the mucous excretories, we know, that when poured out in unusual quantity, it is commonly, at the same time, in a more liquid and acrid form; and may prove, therefore, considerably irritating.

1489.] Though the copious effusion of a more liquid and acrid matter from the mucous excretories, be probably owing to the matter being poured out immediately as it is secreted from the blood into the mucous follicles, without being allowed to stagnate in the latter, so as to acquire that milder quality and thicker consistence we commonly find in the mucus in its natural state; and although we might suppose the excretions of a thin and acrid fluid should always be the effect of every determination to the mucous follicles, and of every stimulant applied to them; yet it is certain, that the reverse is sometimes the case; and that from the mucous follicles, there is frequently an increased excretion of a mucus, which appears in its proper form of a mild, viscid, and thickish matter. This commonly occurs in the case of dysentery; and it has been observed to give a species of diarrhoea, which has been properly named the Diarrhea Mucosa.

1490.] A third source of matter poured into the cavity of the intestines, and occasioning diarrhoea (1475. 3.) is from those preternatural openings produced by diseases in the intestines or neighboring parts. Thus the blood-vessels on the internal surface of the intestines may be opened by erosion, rupture, or anastomosis, and pour into the ca

vity their blood, which, either by its quantity, or by its acrimony, whether inherent, or acquired by stagnation, may sometimes give a diarrhoea evacuating bloody matter. This is what I think happens in that disease which has been called the Melana or Morbus Niger.

1491.] Another preternatural source of matter poured into the cavity of the intestines, is the rupture of abscesses seated either in the coats of the intestines themselves, or in any of the contiguous viscera, which, during an inflamed state, had formed an adhesion with some part of the intestines. The matter thus poured into their cavity may be various; purulent, or sanious, or both together, mixed at the same time with more or less of blood; and in each of these states may be a cause of diarrhoea.

1492.] Amongst the stimuli that may be directly applied to the intestines, and which, by increasing their peristaltic motion, may occasion diarrhoea, I must not omit to mention worms as having frequently that effect.

1493.] I must also mention here a state of the intestines, wherein their peristaltic motion is preternaturally increased, and a diarrhoea produced; and that is, when they are affected with an erythematic inflammation. With respect to the existence of such a state, and its occasioning diarrhoea, see what is said above in 398, and following. Whether it is to be considered as a particular and distinct case of diarrhoea, or is always the same with some of those produced by one or other of the causes above-mentioned, I have not been able to determine.

1494.] Lastly, by an accumulation of alimentary or of other matter poured into the cavity of the intestines from several of the sources above-mentioned, a diarrhoea may be especially occasioned when the absorption of the lacteals, or of other absorbents, is prevented, either by an obstruction of their orifices, or by an obstruction of the mesenteric glands through which alone the absorbed fluids can be transmitted.

In one instance of this kind, when the chyle prepared in the stomach and duodenum is not absorbed in the course of the intestines, but passes off in considerable quantity by the anus, the disease has been named Morbus Cæliacus, or simply and more properly Celiaca; which accordingly I have considered as a species of diarrhoea.

1495.] I have thus endeavored to point out the various species of disease that may come under the general appella