The flowness of the pulse may be referred in part to a morbid state of the brain. That there was an unusual tendency of the blood to the head, is evident from the fuffufion of the face, the redness of the eyes, and the dilatation of the pupils, which latter symptom occurred almost without exception after the middle of September. It is farther deducible from the constant ftupor and drowsiness very frequently accompanying the disease, and from the coma, delirium and hæn.orrhages from the nose. The engorged state alfo of the whole fanguiferous fyftem prevented the free actions of the veffels, as is inferible from the increased frequency of the pulfe after venefection, when it had been preternaturally flow previously to that operation. May we not afcribe that amazing flowness of the pulfe, which occurred in the last stage of the disease, partly to an exhausted state of the excitability of the body from the excessive action of the powers wearing down that property? Blisters very frequently at this time produced no effect, either in a general increase of arterial action, or of the vessels over which they were immediately applied.

The irregular and intermitting pulse may be referred to the different intensity of action of the fame caufe. The latter is more generally obfervable in diseases of the breast and head; and, as Ferriar and Lieutaud have remarked, it is fometimes caused by affections of the heart itself. Many fymptoms of the fever declared an undue accumulation of blood in the vessels of the lungs, as well as of the brain. These circumstances could not fail of occafioning great oppreffion and interruption in the regular action of the heart and arteries. When we excite by any preternatural means the heart of a living animal, we obferve it to contract with violence and rapidity, and then fall into a state of relaxation and momentary torpor. May not fomething fimilar occur in the yellow fever, in which the ftimulus applied to the heart is unufually intenfe? This, aided by the vaft push made upon it, by the too great accumulation of blood, will readily lead to irregularity and intermiffions in its office. Thus I obferved in one cafe, that when the circulation languished

in the extreme veffels, and an increased determination of blood occurred confequently, in the larger veffels, with augmented preffure upon the heart, the intermiffions of the pulfe became more unfrequent. But, when this accumulation was diminished by a general diffufion of the blood through the smallest vessels over the body, this occurrence was lefs remarkable.

Excufe, fir, this digreffion, into which I have been led unwarily: It is my business to ftate facts; but to reafon on them is at prefent unnecessary.

Besides these affections of the pulfe, the vital functions were deranged by

Hemorrhages.

When the fever was uncontroled by medical aid, or treated improperly, the blood-veffels were ruptured by the violent morbid action. In thofe cafes alfo, which were not oppofed with fufficient force, even when the patients were rescued from the grave, hæmorrhages would occur in a small degree before the final crifis of the difeafe. The blood burfted more generally from the nofe; but it was poured forth also from the ears, mouth, bowels, and urinary bladder. A fmall quantity was protruded from an incifion in the arm by a lancet in one cafe, a confiderable time after it had apparently healed.

I could never welcome hæmorrhages in the yellow fever as a favourable occurrence. They indicated the prevalence of excess of action in the arterial fyftem. In typhus fever they generally anticipate a happy termination of the disease because they do not appear, until an increase of action in the vessels begins to indicate a return of healthy vigour. In the yellow fever, the hæmorrhages took place at various periods of time, according to its violence, and the mode in which it had been treated; and the blood loft, though fometimes fmall, would, at other times, amount to a confiderable quantity.

In this manner, fir, were the fufferings of the fanguiferous fyftem indicated. Nor did the organs of refpiration efcape the general marks of derangement in the vital functions.

RESPIRATION was much impeded. It was hurried and laborious. As the coldness of the feafon increased, the determination of the blood to the lungs became more obvious. Pains in the breast became more common; and a cough, with fometimes expectoration of phlegm, more frequently accompanied the difeafe.

A morbid determination of blood to the brain was demonftrated particularly by the fuffufion of the face, the redness of the eyes and dilatation of the pupils; by the hæmorrhages from the nofe and ears; by delirium, coma, or great drow finefs, and by acute pains through different parts of the head.

The increased determination of the blood to the LUNGS, must have caufed an accumulation in the veffels of the brain. But whether actual inflammation or internal hæmorrhages occurred, I cannot determine. I regret extremely that no opportunities were offered to me, during the prevalence of the yellow fever, of examining by diffection its effects upon the body. All my exertions to gratify this with proved ineffectual. It would have been grateful to me to have discovered, what different appearances, different degrees of violence of the fame difeafe were capable of inducing; to have added further testimony to the facts already given by others, or to have detected errors, if any fuch exifted.

The examination of bodies after death is very defirable, because it extends our knowledge of difeafe. Yet we should beware of confiding too much in the appearances exhibited, fince fome important changes may not have been induced, but in the laft ftruggle of departing life. We fhould endeavour to diftinguish between the confequences gradually occafioned by the progress of difeafe, and the effects fuddenly caused by the convulfive conflict with death. The former will teach the natural tendency of the disease, and thereby point out the means of obviating its fatal influence; but the latter by deluding the judgment, will lead us to anticipate events, which may not be always produced, even when death triumphs over the powers of nature or of medicine.

Until we have the means of removing this circumstance be yond all controversy, I am disposed to believe with you, fir, that an engorgement of the blood-veffels of the brain is fufficient to produce the fymptoms described. Nor fhould we be surprised, if we do not detect this caufe by diffection. For, besides the observations of Quin, Girdleftone and Clark, we well know, that even after death itself has occurred, the congestion of the blood-veffels will difappear. You have instanced the departure of the fuffufion of the face, which is a familiar demonftration of the circumftance. If we advert alfo to thofe remedies, which moderate or remove the particular symptoms expreffive of the affection of the brain, they will lead us to afcribe them only to congeftion.

When the contagion acted on the body, without inducing actual fever, it produced reftleffnefs and watching through feveral nights and when fever had been formed, an obstinate wakefulness attended many cafes, perhaps in a great measure from the exceffive violence of pain. When the contagion or miafmata acted with fudden violence, it fometimes induced fyncope: But coma or drowfinefs more commonly marked the affection of the brain.

The nerves were not so much diseased, as to occafion, frequently, tremors or twitching of the tendons. They, in fome cafes, acquired fuch a morbid degree of fenfibility, as to render the whole furface of the body fore to the touch. These cafes terminated fatally, but were alfo free from fubfultus tendinum. Hiccup fometimes occurred, and was in general premonitory of a fatal iffue. Sydenham speaks of it, as occurring after exceffive vomiting: I remarked the truth of this obfervation in the yellow fever. The hiccup was fometimes aggravated by very great flatulence of the stomach.

The pains accompanying the yellow fever were more or lefs acute in every cafe. They extended through the head, back, and knees. In one very violent inftance, the former only was affected. In others, the head would be but slightly diseased at the beginning of the fever, while the back and knees fuffered

with excruciating torture. The pains were not always confined to the parts mentioned, but pervaded every part of the body-the arms and legs being included in their range.

The pain of the head was differently feated-in the eyes, in one or both temples, in the forehead, on the fummit, and on the back of the head. It winded in one inftance through the cartilage of the right ear. It fometimes appeared to be fixed in the middle of the brain.

In the back it was generally confined to the lumbar vertebræ; but extended occafionally through the facrum, and pierced forward through the bowels. In one cafe, the pain of the extremities was confined to one arm; in another, it was fixed only in one leg.

The torture from pain was in many inftances exquifitely acute. A gentleman declared in anguish, that the pain through his eyes was enough to deprive him of his fenfes :" and another confeffed, that the pains in his legs were fo acute, "that he could cry like a child." They often caufed an inceffant toffing from one part of the bed to another, but this inquietude was increased by finding relief in no pofition. To gain a respite from it, required other means, to be hereafter mentioned.

The pains were not always fixed in the fame places with invariable violence. I have frequently obferved their abatement in one part fucceeded by increased vehemence in another. Thofe of the head and back appeared in feveral inftances to alternate with each other. In the infidious remiffions of the fever, when the heat of the fkin moderated,---I very feldom remarked a proportionable remiffion of pain.

The breaft, if debilitated by former attacks of disease, was always particularly affected with pain. But in the case of a gentleman, whofe liver had been two or three times inflamed, I did not perceive that this vifcus fuffered fingularly from the yellow fever.

The mind fuffered from delirium, but was fometimes unaffected with this fymptom through the whole course of the difeafe. I was informed of one unfortunate cafe, in which