Return to Fever 1793
A Defence of Blood-letting,
as a Remedy for Certain Diseases
from Rush's Medical Inquiries and Observations. Volume 4, Philadelphia 1815
Blood-Letting, as a remedy for fevers, and certain other diseases, having lately been the subject of much discussion, and many objections having been made to it which appear to be founded in error and fear, I have considered that a defence of it, by removing those objections, might render it more generally useful, in every part of the United States.
I shall begin this subject by remarking, that blood-letting is indicated, in fevers of great morbid excitement,
1. By the sudden suppresion or diminution of the natural discharges by the pores, bowels, and kidneys, whereby a plethora is induced in the system.
2. By the habits of the persons who are most subject to such fevers.
3. By the phenomena of fever. I have attempted to prove that the higher grades of fever depend upon morbid and excessive action in the blood-vessels. It is connected of course, with preternatural sensibility in their muscular fibres. The blood is the most powerful irritant which acts upon them. By abstracting a part of it, we lessen the principal cause of the fever. The effect of blood-letting is as immediate and natural in removing fever, as the abstraction of a particle of sand is, to cure inflammation of the eye, when it arises from that cause.
4. By the symptoms of the first stage of violent fevers such as sleepiness and an oppressed pulse, or by delirium, with a throbbing pulse, and great pains in every part of the body.
5. By the rupture of the blood-vessels, which takes place from the quantity or impetus of the blood in fevers of great morbid action. Let no one call bleeding a cruel or unnatural remedy. It is one of the specifics of nature; but in the use of it she seldom affords much relief. She  frequently pours the stimulating and oppressing mass of blood into the lungs and brain; and when she finds an outlet for it through the nose, it is discharged either in such a deficient or excessive quantity, as to be useless or hurtful. By artificial blood-letting , we can chuse the time and place of drawing blood, and we may regulate its quantity by the degrees of action in the blood-vessels. The disposition of nature to cure violent morbid action by depletion, is further manifested by her substituting, in the room of blood-letting, large, but less safe and less beneficial , evacuations from the stomach and bowels.
6. By the structure and use of the spleen. I have called it in my lectures upon physiology, a bason furnished by nature to hold redundant blood, or to afford it a temporary asylum, when the blood-vessels are unduly excited. Now the spleen is sometimes too small, and often so over-charged with blood, or so obstructed, that it cannot perform this office, in which case blood-letting is indicated. The great enlargement and engorgement of the spleen in fatal cases of bilious fever where sufficient bleeding has not been used, prove he truth of this remark. The relief which bleeding gives in chronic and winter intermittents, is probably occasioned by the spleen being so much obstructed, as not to receive the blood in a paroxysm of fever. The lancet here performs its vicarious office.
7. By the relief which is obtained in fevers of violent action by remedies of less efficacy (to be mentioned hereafter), which act indirectly in reducing the force of the sanguiferous system.
8. By the immense advantages which have attended the use of blood-letting in violent fevers, when used at a proper time, and in a quantity suited to the force of the disease. I shall briefly enumerate these advantages.
1. It frequently strangles a fever, when used in its forming state, and thereby saves much pain, time, and expense to a patient.
2. It imparts strength to the body, by removing the depression which is induced by the remote cause of the fever. It moreover obviates a disposition to faint, which arises from this state of the system.
3. It reduces the uncommon frequency of the pulse.  The loss of ten ounces of blood reduced Miss Sally Eyre's pulse from 176 strokes to 140, in a few minutes, in the fever of year 1794. Dr. Gordon mentions many similar instances of its reducing the frequency of the pulse, in the puerperile fever.
4. It renders the pulse more frequent when it is preternaturally slow.
5. It checks nausea and vomiting, which attend the malignant state of fever. Of this I saw many instances in the year 1794. Dr. Poissonier Desperrieres confirms this remark, in his Account of the Fevers of St. Domingo; and adds further, that it prevents, when sufficiently copious, the troublesome vomiting which often occurs on the fifth day of the yellow fever. (Traite des Fievres de l'Isle de St. Domingo, vol. ii, p.76.) It has the same effect in preventing the diarrhoea in the measles.
6. It renders the bowels, when costive, more easily moved by purging physic.
7. It renders the action of mercury more speedy and more certain, in exciting a salivation.
8. It disposes the body to sweat spontaneously, or renders diluting and diaphoretic medicines more effectual for that purpose.
9. It suddenly removes a dryness, and gradually a blackness, from the tongue. Of the former effect of bleeding, I saw two instances, and of the latter, one, during the autumn of 1794.
10. It removes or lessens pain in every part of the body, and more especially the head.
11. It removes or lessens the burning heat of the skin, and the burning heat of the stomach, so common and so distressing in the yellow fever.
12. It removes a constant chilliness, which sometimes continues for several days, and which will neither yield to cordial drinks, nor warm bed clothes.
13. It checks such sweats as are profuse without affording relief, and renders such as are partial and moderate, universal and salutary.
14. It sometimes checks a diarrhoea and tenesmus, after astringent medicines have been given to no purpose. This has often been observed in the measles. 
15. It suddenly cures the intolerance of light which accompanies many of the inflammatory states of fever.
16. It removes coma. Mr. Henry Clymer was suddenly relieved of this alarming symptom, in the fever of 1794, by the loss of twelve ounces of blood.
17. It induces sleep. This effect of blood-letting is so uniform, that it obtained, in the year 1794, the name of an anodyne in several families. Sleep sometimes stole upon the patient while the blood was flowing.
18. It prevents effusions of serum and blood. Haemorrhages seldom occur, where bleeding has been sufficient.
19. It belongs to this remedy to prevent the chronic diseases of cough, consumption, jaundice, abscess in the liver, and all the different states of dropsy which so often follow autumnal fevers.
My amiable friend, Mrs. Lenox, furnished an exception to this remark, in the year 1794. After having been cured of the yellow fever by seven bleedings, she was affected, in consequence of taking a ride, with a slight return of fever, accompanied by an acute pain in the head, and some of the symptoms of dropsy of the brain. As her pulse was tense and quick, I advised repeated bleedings to remove it. This prescription, for reasons which it is unnecessary to relate, was not followed at that time, or in the manner, in which it was recommended. The pain, in the mean time, became more alarming. In this situation, two physicians were proposed by her friends to consult with me. I objected to them both, because I knew their principles and mode of practice to be contrary to mine, and that they were proposed only with a view of wresting the lancet from my hand. From this desire to avoid controversy with my brethren, where conviction was impossible on either side, as well as to obviate all cause of complaint by my patient's friends, I offered to take my leave of her, and to resign her wholly to the care of the two gentlemen who were proposed to attend her with me. To this she objected in a decided manner. But that I might not be suspected of an undue reliance upon my own judgment, I proposed to call upon Dr. Griffitts or Dr. Physick to assist me in my attendence upon  her. Both these physicians had renounced the prejudices of the schools in which they had been educated, and had conformed their principles and practices to the present improving state of medical science. My patient preferred Dr. Griffitts, who, in his first visit to her, as soon as he felt her pulse, proposed more bleeding. The operation was performed by the doctor himself, and repeated daily for five days afterwards. From an apprehension that the disease was so fixed as to require some aid to blood-letting, we gave her calomel in such large doses as to excite a salivation. By the use of these remedies she recovered slowly, but so perfectly as to enjoy her usual health.
20. Bleeding prevents the termination of malignant disease, in the gangrenous state of fever. This effect of blood-letting will enable us to understand some things in the writings of Dr. Morton and Dr. Sydenham, which at first sight appear to be unintelligible. Dr. Morton describes what he calls a putrid fever, which was epidemic and fatal, in the year 1678. Dr. Sydenham, who practiced in London at the same time, takes no notice of this fever. The reason of his silence is obvious. By copious bleeding, he prevented the fever of that year from running on to the gangrenous state, while Dr. Morton, by neglecting to bleed, created the supposed putrid fevers which he has described.
It has been common to charge the friends of blood-letting with temerity in their practice. From this view which has been given of it, it appears, that it would be more proper to ascribe timidity to them, for they bleed to prevent the offensive and distressing consequences of neglecting it, which have been mentioned.
21. It cures, without permitting a fever to put on those alarming symptoms, which excite constant apprehensions of danger and death, in the minds of patients and their friends. It is because these alarming symptoms are prevented, by bleeding, that patients are sometimes unwilling to believe they had been cured by it, of a malignant fever. Thus, the Syrian leper of old, viewed the water of Jordan as too simple and too common to cure a formidable disease, without recollecting that the remedies for the greatest  evils of life are all simple, and within the power of the greatest part of mankind.
22. It prepares the way for the successful use of the bark and other tonic remedies, by destroying, or so far weakening, a morbid action in the blood-vessels, that a medicine of a moderate stimulus afterwards exceeds it in force, and thereby restores equable and healthy action to the system.
23. Bleeding prevents relapses. It, moreover, prevents that predisposition to the intermitting and pleuritic states of fever, which so frequently attack persons in the spring, who have had the bilious remitting fever in the preceding autumn.
But great and numerous as the advantages of blood-letting are in fevers, there have been many objections to it. I shall briefly enumerate, and endeavour to refute the errors upon this subject.
Blood-letting has been forbidden by physicians, by the following circumstances, and states of the system.
1. By warm weather. Galen bled in a plague, and Araeteus in a bilious fever, in a warm climate. Dr. Sydenham and Dr. Hillary inform us, that the most inflammatory fevers occur in, and succeed hot weather. Dr. Cleghorn prescribed it copiously in the warm months, in Minorca. Dr. Mosely cured the yellow fever by this remedy, in Jamaica. Dr. Broadbelt, and Dr. Weston in the same island, have lately adopted his successful practice. Dr. Desportes speaks in the highest terms of it in all the inflammatory disease of St. Domingo. He complains of the neglect of it in the rheumatism, in cosequence of which, he says, the disease produces abscesses in the lungs. Dr. Pugnet says the native physicians of upper Egypt bleed in all violent diseases. They are governed in their practice by the state of the pulse in the temples, and when it does not afford the indication sought for, they regulate the use of the lancet by the greater or less red colour of the body. I have never, in any year of my practice, been restrained by the heat of summer in the use of the lancet, where the pulse has indicated it to be necessary, and have always found the same advantages from it, as when I have prescribed it in the winter or spring months. 
In thus deciding in favour of bleeding in warm weather, I do not mean to defend its use to the same extent, as to diseases, or to quantity, in the native and long settled inhabitants of hot climates, as in persons who have recently migrated to them, or who live in climates alternately hot and cold.
2. Being born, and having lived in a warm climate. This is so far from being an objection to blood-letting in an inflammatory disease, that it renders it more necessary. I think I have lost several West-India patients from the influence of this error.
3. Great apparent weakness. This, in acute and violent fevers, is always from a depressed state of the system. It resembles, in so many particulars, that weakness which is the effect of the abstraction of stimulus, that it is no wonder they have been confounded by physicians. This sameness of symptoms from opposite states of the system is taken notice of by Hippocrates. He describes convulsions, and particularly a hiccup, as occurring equally from repletion and inanition, which answers to the terms of depression, and debility from action and abstraction. The natural remedy for the former is depletion, and no mode of depleting is so effectual and safe as blood-letting. But the great objection to this remedy is, when a fever of great morbid excitement affects persons of delicate constitutions, and such as have long been subject to debility of a chronic kind. In this state of the system, there is the same morbid and preternatural action in the blood-vessels, that there is in persons of robust habits, and the same remedy is necessary to subdue it in both cases. It is sometimes indicated in a larger quantity in weakly than in robust people, by the plethora which is more easily induced in their relaxed and yielding blood-vessels, and by the greater facility with which ruptures and effusions take place in their viscera. Thus it is more necessary to throw overboard a large part of the cargo of an old and leaky vessel in a storm, than of a new and strong one. I know that vomits, purges, sweats, and other evacuating remedies, are prefered to bleeding in weakly constitutions but I hope to show hereafter, that bleeding is not only more effectual, but more safe in such habits, than any other depleting remedy. 
4. Infancy and childhood. Bleeding is so far from being forbidden by these stages of life, that it is called for in a greater degree under equal circumstances, than in the diseases of adults, by the peculiar excitability of the blood-vessels of children, by the difficulty of reducing their systems by means of sweats, and in diseases of the lungs and trachea, by their inability under two years old, to remove the irritation excited by phlegm and mucus in those organs, by expectoration. Dr. Sydenham bled children in the hooping cough, and in dentition. I bled my eldest daughter when she was but six weeks old, for convulsions brought on by an excessive dose of laudanum given to her by her nurse; and I bled one of my sons twice, before he was two months old, for an acute fever which fell upon his lungs and bowels. In both cases, life appeared to be saved by this remedy. I could mention many more instances in which it has snatched from the grave, children under three and four months old, by being used from three to five times in the ordinary course of their acute disease.
5. Old age. The increase of appetite in old people, their inability to use sufficient exercise, whereby their blood-vessels become relaxed, plethoric, and excitable, and above all, the translation of the strength of the muscles to arteries, and of the plethora to the veins, all indicate bleeding to be more necessary (in equal circumstances) in old, than in middle aged people. My practice in the diseases of old people has long been regulated by the above facts. I bled Mrs. Fullarton twice in a pleurisy in January, 1804, in the 84th year of her age, and thereby cured her disease. I drew six and thirty ounces of blood, in the year 1806, at three bleedings, from Mr. Israel Jacobs in the 91st year of his age, in a bilious fever, in the course of a few days. He was cured by this remedy, and at this time, July 29, 1809, enjoys good health. I am not the author of this bold practice. Botallus left a testimony in favour of it nearly 200 years ago, and it has since been confirmed by the experience of Hoffman, and many other physicians. An ignorance of, or inattention to this change in the state  of the blood vessels, in persons in the decline of life, and the neglect of the only remedy indicated by it, is probably the reason why diseases often prove fatal to them, which in early or middle life cured themselves, or yielded to a single dose of physic, or a few ounces of bark.
6. The time of menstruation. The uterus, during this period, is in an inflamed state, and the whole system is plethoric and excitable, and of course disposed to a violent degree of fever, from all the causes which excite it. Bleeding, therefore, is more indicated, in fever of great morbid action, at this time, than any other. Formerly the natural discharge from the uterus was trusted to, to remove a fever contracted during the time of menstruation; but what relief can the discharge of four or five ounces of blood from the uterus afford, in a fever which requires the loss of 50, or perhaps of 100 ounces to cure it?
7. Pregnancy. The inflammation and distention induced upon the uterus by pregnancy, and the inflammatory diathesis thereby imparted to the whole system, render bleeding, in the acute states of fever, more necessary than at other times. I have elsewhere mentioned the advantages of bleeding pregnant women, in the yellow fever. I did not learn the advantages of the practice in that disease. I bled Mrs. Philler 11 times in seven days, in a pleurisy during her pregnancy, in the month of March, 1783; and Mrs. Kirby 16 times in the same condition, by my orders, in the winter of 1786, in a similar disease. All these women recovered, and the children they carried during their illness, are at this time alive, and in good health.
8. Fainting after bleeding. This symptom is accidental in many people. No inference can be drawn from it against blood-letting. It often occurs after the first and second bleedings in a fever, but in no subsequent bleeding, though it be repeated a dozen times. Of this I saw several instances, in the yellow fever of 1794. The pulse, during the fainting, is often tense and full.
9. Coldness of the extremities, and of the whole body. This cold state of fever when it occurs early, yields more readily to bleeding, than to the most cordial medicines.
10. Sweats are supposed to forbid blood-letting. I have seen two instances of death, from leaving a paroxysm  of malignant fever to terminate itself by sweating. Dr. Sydenham has taught a contrary practice in the following case. "While this constitution (says the doctor) prevailed, I was called to Dr. Morice, who then practiced in London. He had this fever, attended with profuse sweats, and numerous petechiae. By the consent of some other physicians, our joint friends, he was blooded, and rose from his bed, his body being first wiped dry. He found immediate relief from the use of a cooling diet and medicines, the dangerous symptoms soon going off; and by continuing this method he recovered in a few days." (Wallis's edition, vol. i, p. 210) In the same fever, the doctor adds further, "For though one might expect great advantages in pursuing an indication taken from what generally proves serviceable (viz. sweating,) yet I have found, by constant experience, that the patient not only finds no relief, but, contrariwise, is more heated thereby; so that frequently a delirium, petechiae, and other very dangerous symptoms immediately succeed such sweats." (Vol. i. p. 208.)
Morgagni describes a malignant fever which prevailed in Italy, in which the patients died in profuse sweats, while their physicians were looking for a crisis from them. Bleeding would probably have checked these sweats, and cured the fever.
11. Dissolved blood, and an absence of an inflammatory crust on its crassamentum. I shall hereafter place dissolved blood at the highest point of a scale, which is intended to mark the different degrees of morbid action in the system. I have mentioned in the Outlines of the Phenomena of Fever, that it is the effect of a tendency to a palsy, induced by the violent force of impression upon the blood-vessels, rending and tearing the blood to pieces. This appearance of the blood in certain states of fever, instead of forbidding bleeding, is the most vehement call of the system for it. Nor is the absence of a crust on the crassementum of the blood, a proof of the absence of great morbid daithesis, or a signal to lay aside the lancet. On the contrary, I shall show hereafter, that there are several appearances of the blood which indicate  more morbid action in the blood-vessels than a sizy or inflammatory crust.
12. An undue proportion of serum to crassamentum in the blood. This predominance of water in the blood has often checked sufficient blood-letting. But it should be constantly disregarded, while it is attended with those states of pulse (to be mentioned hereafter) which require bleeding.
13. The presence of petechiae on the skin. These, I have elsewhere said, are the effects of the gangrenous state of fever. Dr. Sydenham and Dr. de Haen have taught the safety and advantage of bleeding, when these spots are accompanied by an active pulse. A boy of Mr. John Carrol owes his recovery from the small-pox to the loss of fifty ounces of blood, by five bleedings, at a time when nearly every pock on his arms and legs had a purple appearance. Louis XIV was bled five times in the small-pox, when he was but thirteen years of age, and thereby probably saved from the grave, to the great honour and emolument of the single physician who urged it against the advice of all other physicians of the court. Dr. Cleghorn mentions a single case of the success of bleeding in the petechial small-pox. His want of equal success afterwards, in similar cases, was probably occasioned by his bleeding too sparingly, that is, but three or four times.
Abscesses and sore breasts, which accompany or succeed fever, are non objections to blood-letting, provided the pulse indicate the continuance of inflammatory diathesis. They depend frequently upon the same state of the system as livid effusions on the skin.
14. The long duration of fever. Inflammatory diathesis is often protracted for many weeks, in the chronic state of fever. It, moreover, frequently revives after having disappeared, from an accidental irritant affecting some part of the body, particularly the lungs and the brain. I bled a young man of James Cameron, in the autumn of 1794, four times between the 20th and 30th days of a chronic fever, in consequence of a pain in the side, accompanied by a tense pulse, which suddenly came on after the 20th day of his disease. His blood was sizy.  His pain and tense pulse were subdued by the bleeding and he recovered. I bled the late Dr. Prowl twelve times, in a fever which continued thirty days, in the autumn of the year 1800. I wish these cases to be attended to by young practitioners. The pulmonary consumption is often the effect of a chronic fever, terminating with fresh inflammatory symptoms, by effusions in the lungs. It may easily be prevented by forgetting the number of the days of our patient's fever, and treating the pulmonary affection as it it were a recent complaint.
15. Tremors and slight convulsions in the limbs. Bark, wine, Laudanum, and musk are generally prescribed to remove these symptoms; but, to be effectual, they should, in most cases, be preceded by the loss of a few ounces of blood.
16. Bleeding is forbidden after the fifth or seventh day in a pleurisy. This prohibition was introduced into medicine at a time when a fear was entertained of arresting the progress of nature in preparing and expelling morbific matter from the system. From repeated experience I can assert, that bleeding is safe in every stage of pleurisy in which there is pain, and a tense and oppressed pulse; and that it has, when used for the first time after the fifth and seventh days, saved many lives. Bleeding has likewise been limited to a certain number of ounces in several states of fever. Were the force of the remote cause of a fever, its degree of violence, and the habits of the subject of it, always the same, this rule would be a proper one; but, this not being the case, we must be governed wholly by the conditon of the system, manifested chiefly by the state of the pulse. To admit of copious bleeding in one state of fever, and not in another, under equal circumstances of morbid excitement, is to prescribe for its name, and to forget the changes which climate, season, and previous habits create in all its different states.
17. The loss of a sufficient quantity of blood is often prevented by patients being apparently worse, after the first or second bleeding. This change for the worse, shows itself in some one or more of the following symptoms, viz. increase of heat, chills, delirium, haemorrhages, convulsions,  nausea, vomiting, faintness, coma, great weakness, pain, a tense, after a soft pulse, and a reduction of it in force and frequency. They are all occasioned by the system rising suddenly from a state of extreme depression, in consequence of the abstraction of the pressure of the blood to a state of vigour and activity, so great, in some instances, as to reproduce a depression below what existed in the system before a vein was opened; or it is occasioned by a translation of morbid action from one part of the body to another.
The chills which follow bleeding are the effects of a change in the fever, from an uncommon to a common state of malignity. They occur chiefly in those violent cases of fever which come on without a chilly fit.
The haemorrhages produced by bleeding are chiefly from the nose, haemorrhoidal vessels, or uterus, and of course are, for the most part, safe.
Uncommon weakness, succeeding blood-letting is the effect of sudden depression induced upon the whole system, by the cause before mentioned, or of a sudden translation of the excitement of the muscles into the blood-vessels, or some other part of the body. These symptoms, together with all others which have been mentioned, are so far from forbidding, that they almost forcibly indicate a repitition of blood-letting.
I shall briefly illustrate, by the recital of three cases, the good effects of bleeding, in removing pain, and the preternatural slowness and weakness of the pulse, when produced by the use of that remedy.
In the month of June of 1795, I visited Dr. Say in a malignant fever, attended with pleuritic symptoms, in consultation with Dr. Physick. An acute pain in his head followed six successive bleedings. After a seventh bleeding, he had no pain. His fever soon afterwards left him. In thus persevering in the use of a remedy, which, for several days, appeared to do harm, we were guided wholly by the state of his pulse, which uniformly indicated, by its force, the necessity of more bleeding.
In the autumn of 1794, I was sent for to visit Samuel Bradford, a young man of about 20 years of age, son of Mr. Thomas Bradford, who was ill with the reigning  malignant epidemic. His pulse was at 80. I drew about 12 ounces of blood from him. Immediately after his arm was tied up, his pulse fell to 60 strokes in a minute. I bled him a second time, but more plentifully than before, and thereby in a few minutes, brought his pulse back again to 80 strokes in a minute. A third bleeding the next day aided by the usual purging physic, cured him in a few days after.
In the month of March, 1795, Dr. Physick requested me to visit, with him Mrs. Fries, the wife of John Fries, in a malignant fever. He had bled her four times. After the fourth bleeding, her pulse suddenly fell, so as to scarcely be perceptible. I found her hands and feet cold, and her countenance ghastly, as if she were in the last moments of life. In this alarming situation, I suggested nothing to Dr. Physick but to follow his judgment, for I knew that he was master of that law of the animal economy which resolved all her symptoms into an oppressed state of the system. The doctor decided in a moment in favor of more bleeding. During the flowing of the blood the pulse rose. At the end of three, ten, and seventeen hours it fell, and rose again by three successive bleedings, in all of which she lost about thirty ounces of sizy blood. So great was the vigour acquired by the pulse, a few days after the paroxysms of depression, which have been described, were relieved, that it required seven more bleedings to subdue it. I wish the history of these two cases to be carefully attended to by the reader. I have been thus minute in the detail of them, chiefly because I have heard of practitioners who have lost patients by attempting to raise a pulse that had been depressed by bleeding, in a malignant fever, by means of cordial medicines, instead of repeated use of the lancet. The practice is strictly rational; for, in proportion as the blood-vessels are weakened by pressure, the quantity of blood to be moved should be proportioned to the diminution of their strength.
This depressed state of the pulse, whether induced by a paroxysm of fever, or by blood-letting, is sometimes attended with a strong pulsation of the arteries in the bowels and head. 
I have mentioned, among the apparent bad effects of bleeding, that it sometimes changes a soft into a tense pulse. Of this I saw a remarkable instance in Captain John Berry, in the autumn of 1795. After the loss of 130 ounces of blood in a malignant fever, his pulse became so soft as to indicate no more bleeding. In this situation he remained for three days, but without mending as rapidly as I expected from the state of his pulse. On the fourth day he had a haemorrhage from his bowels, from which he lost above a pint of blood. His pulse now suddenly became tense, and continued so for two or three days. I ascribed this change in his pulse to the vessels of the bowels, which had been oppressed by congestion, being so much relieved by the haemorrhages, as to resume inflammatory action. I have observed a similar change to take place in the pulse, after a third bleeding, in a case of haemorrhoidal fever, which came under my notice in the month of January, 1803. It is thus we see the blood-vessels, in a common phlegmon, travel back again, from a tendency to mortification, to the red colour and pain of common inflammation.
From a review of the commotions excited in the system by bleeding, a reason may be given why physicians, who do not bleed in the depressed state of the pulse, have so few patients in what they call the malignant fevers, compared with those who use a contrary practice. The disease, in such cases, being locked up, is not permitted to unfold its true character; and hence patients are said to die of apoplexy, lethargy, cholera, dysentery, or nervous fever, who, under a different treatment, would have exhibited all the marks of an ordinary malignant fever.
In obviating the objections to blood-letting from its apparent evils, I have said nothing of the apparent bad effects of other remedies. A nausea is often rendered worse by an emetic, and pains in the bowels are increased by a purge. But these remedies notwithstanding maintain, and justly too, a high character among physicians.
19. Bleeding has been accused of bringing on a nervous, or the chronic state of fever. The use of this remedy, in a degree so moderate as to obviate the putrid or gangrenous state of fever only, may induce the chronic  state of fever; for it is the effect, in this case, of the remains of inflammatory diathesis in the blood-vessels; but when blood is drawn proportioned to the morbid action in the system, it is impossible for a chronic fever to be produced by it. Even the excessive use of blood-letting, however injurious it may be in other respects, cannot produce a chronic fever, for it destroys morbid action altogether in the blood-vessels.
20. Bleeding has been charged with being a weakening remedy. I grant that it is so, and in this, its merit chiefly consists. The excessive morbid action of the blood-vessels must be subdued in part in a fever, before stimulating remedies can be given with safety or advantage. Now this is usually attempted by depleting remedies, to be mentioned hereafter, or it is left to time and nature, all of which are frequently either deficient, or excessive in their operations; whereas bleeding, by suddenly reducing the morbid action of the blood-vessels to a wished-for point of debility, saves a great and unnecessary waste of excitability, and thus prepares the body for the exhibition of such cordial remedies as are proper to remove the debility which predisposed to the fever.
21. It has been said that bleeding renders the habitual use of it necessary to health and life. This objection to blood-letting is founded upon an ignorance of the difference between the healthy, and morbid action of the blood vessels. Where blood is drawn in health, such a relaxation is induced in the blood-vessels, as to favour the formation of plethora, which may require habitual bleeding to remove it; but where blood is drawn only in the inflammatory state of fever, the blood-vessels are reduced from a morbid degree of strength to that which is natural, in which state no predisposition to plethora is created, and no foundation laid for periodical blood-letting. But there are cases which require even this evil, to prevent a greater. Thus we cure a strangulated hernia, when no fever attends, by the most profuse bleeding. The plethora and predisposition to disease which follow it are trifling, compared with preventing certain and sudden death.
22. Bleeding has been accused of bringing on an  intermitting fever. This is so far from being an objection to it, that it should be considered as a new argument in its favour; for when it produces that state of fever, it converts a latent, and perhaps a dangerous disease, into one that is obvious to the senses, and under the dominion of medicine. Nor is it an objection to blood-letting, that, when used in an inflammatory intermittent, it sometimes changes it into a continual fever. An instance of the good effects of this change occurred in the Pennsylvania hospital, in an obstinate tertian, in the year 1804. The continual fever, which followed the loss of blood, was cured in a few days, and by the most simple remedies.
23. It has been said that bleeding, more especially when it is copious, predisposes to effusions of serum in the lungs, chest, bowels, limbs, and brain. In replying to this objection to bleeding, in my public lectures, I have addressed my pupils in the following language: "Ask the poor patients who come panting to the door of our hospital, with swelled legs and hard bellies, every fall, whether they have been too copiously bled, and they will tell you, that no lancet has come near their arms. Ask the parents who still mourn the loss of children who have died, in our city, of the internal dropsy of the brain, whether they were destroyed by excessive blood-letting? If the remembrance of the acute sufferings which accompanied their sickness and death will permit these parents to speak, they will tell you, that every medicine, except bleeding, had been tried to no purpose in their children's diseases. Go to those families in which I have practiced for many years, and inquire, whether there is a living or dead instance of dropsy having followed, in any one of them, the use of my lancet? Let the undertakers and grave-diggers bear witness against me, if I have ever, in the course of my practice, conveyed the body of a single dropsical patient into their hands, by excessive blood-letting? No. Dropsies, like abscesses and gangrenous eruptions on the skin, arise, in most cases, from the want of sufficient bleeding in inflammatory diseases. Debility, whether induced by action or abstraction, seldom disposes to effusion. Who ever heard  of dropsy succeeding famine? And how rarely do we see it accompany the extreme debility of old age?
"If ever bleeding kills," says Bottallus, either directly or indirectly, through the instrumentality of other diseases, "it is not from its excess, but because it is not drawn in a sufficient quantity, or at a proper time." (Cap. viii S 4) And, again, says this excellent writer, "One hundred thousand men perish from the want of blood-letting, or from its being used out of time, to one who perishes from too much bleeding, prescribed by a physician." (Cap. xxxvi S 4)
It is remarkable, that the dread of producing a dropsy by bleeding, is confined chiefly to its use in malignant fevers; for the men who urge this objection to it, do not hesitate to draw four or five quarts of blood in the cure of a pleurisy. The habitual association of the lancet with this disease, has often caused me to rejoice when I heard a patient complain of a pain in his side, in a malignant fever. It insured to me his consent to the frequent use of the lancet, and it protected me, when it was used successfully, from the clamours of the public, for few people censure copious bleeding in a pleurisy.
24. Against blood-letting it has been urged, that the Indians of our country cure their inflammatory fevers without it. To relieve myself from the distressing obloquy to which my use of this remedy formerly exposed me, I have carefully sought for, and examined their remedies for those fevers, with a sincere desire to adopt them; but my inquiries have convinced me, that they are not only disproportioned to the habits and diseases of civilized life, but that they are far less successful than blood-letting, in curing inflammatory fevers which occur among the Indians themselves.
25. Evacuating remedies of another kind have been said to be more safe than bleeding, and equally effectual, in reducing the inflammatory state of fever. I shall enumerate each of these evacuating remedies, and then draw a comparative view of their effects with blood-letting. They are,
I. Vomits 
IV. Salivation. And
I. Vomits have often been effectual in curing fevers of a mild character. They discharge offensive and irritating matters from the stomach; they lessen the fullness of the blood-vessels, by determining the serum of the blood through the pores; and they equalize the excitement of the system, by inviting its excessive degrees from the blood-vessels to the stomach and muscles, but they are,
1. Uncertain in their operation, from the torpor induced by the fever upon the stomach.
2. They are unsafe in many conditions of the system, as in pregnancy, and disposition to apoplexy and ruptures. Life has sometimes been destroyed by their inducing cramps, haemorrhage, and inflammation in the stomach.
3. They are not subject to the controul of a physician, often operating more, or less than was intended by him, or indicated by the disease.
4. They are often ineffectual in mild, and always so in fevers of great morbid action.
II. Purges are useful in discharging acrid faeces and bile from the bowels in fevers. They act, moreover, by creating an artificial weak part, and thus excite morbid excitement from the blood-vessels to the bowels. They likewise lessen the quantity of blood, by preventing fresh accessions of chyle being added to it; but like vomits they are,
1. Uncertain in their operation; and from the same cause. Many ounces of salts and castor oil, and whole drachms of calomel and jalap, have often been given, without effect, to remove the costiveness which is connected with the malignant state of fever.
2. They are not subject to the direction of a physician, with respect to the time of their operation, or the quantity or quality of matter they are intended to discharge from the bowels. 
3. They are unsafe in the advanced stage of fevers, Dr. Physick informed me, that three patients died in the water-closet, under the operation of purges, in St. George's hospital, during his attendance upon it. I have seen death, in several instances, succeed a plentiful spontaneous stool in debilitated habits.
III. Sweating was introduced into practice at a time when morbific matter was supposed to be the proximate cause of fever. It acts, not by expelling any thing exclusively morbid from the blood, but by abstracting a portion of fluid parts, and thus reducing the action of the blood-vessels. This mode of curing fever is still fashionable in genteel life. It excites no fear, and offends no sense. The sweating remedies have been numerous, and fashion has reigned as much among them, as in other things. Alexipharmic waters, and powders, and all the train of sudorific medicines, have lately yielded to the different preparations of antimony, particularly to James's powder. I object to them all,
1. Because they are uncertain; large and repeated doses of them being often given to no purpose.
2. Because they are slow and disagreeable, where they succeed in curing fevers.
3. Because, like vomits and purges, they are not under the direction of a physician, with respect to the quantity of fluid discharged by them.
4. Because they are sometimes, even when most profuse, ineffectual in the cure of fever.
5. The preparations of antimony, lately employed for the purpose of exciting sweats, are by no means safe. They sometimes convulse the system by a violent puking. Even the boasted James's powder has done great mischief. Dr. Goldsmith and Mr. Howard, it is said, were destroyed by it.
None of these objections to sweating remedies are intended to disuade from their use, when nature shows a disposition to throw off fever by the pores of the skin; but, even then, they often require the aid of bleeding to render them effectual for that purpose.
IV. Mercury, the Sampson of the materia medica, after having subdued the venereal disease, the tetanus, and  many other formidable diseases, has lately added to its triumphs and reputation, by overcoming the inflammatory and malignant state of fever. I shall confine myself, in this place, to its depleting operation, when it acts by exciting a salivation. From half pound to two pounds of fluid are discharged by it in a day. The depletion in this way is gradual, whereby fainting is prevented. By exciting and inflaming the glands of the mouth and throat, excitement and inflammation are abstracted from more vital parts. In morbid congestion and excitement in the brain, a salivation is of eminent service, from the proximity of the discharge to the part affected. But I object to it, as an exclusive vacuant in the cure of fever.
1. Because it is sometimes impossible, by the largest doses of mercury, to excite it, when the exigences of the system render it most necessary.
2. Because it is not so quick in its operation, as to be proportioned to the rapid progress of the malignant state of fever.
3. Because it is at all times a disagreeable, and frequently a painful remedy, more especially where the teeth are decayed.
4. Because it cannot be proportioned in its duration, or in the quantity of fluid discharged by it, to the violence or changes in the fever.
Dr. Chisholm relied, for the cure of the Beullam fever at Grenada, chiefly upon this evacuation. I have mentioned the ratio of success which attended it.
V. Blisters are useful in depleting from those parts which are the seats of topical inflammation. The relief obtained by them in this way more than balances their stimulus upon the whole system. I need hardly say, that their effects in reducing the morbid and excessive action of the blood-vessels are very feeble. To depend upon them in cases of great inflammatory action, is an unwise as it would be to attempt to bale the water from a leaky and sinking ship by the hollow of the hand, instead of discharging it by two or three pumps.
VI. Abstemious diet has sometimes been prescribed as a remedy for fever. It acts directly by the abstraction of the stimulus of food from the stomach, and indirectly  by lessening the quantity of blood. It can bear no proportion, in its effects, to the rapidity and violence of an inflammatory fever. In chronic fever, such as occurs in the pulmonary consumption, it has often been tried to no purpose. Long before it reduces the pulse, it often induces such relaxation in the tone of the stomach and bowels to accelerate death. To depend upon it therefore in the cure of inflammatory fever, whether acute or chronic, is like trusting to the rays of the sun to exhale the water of an overflowing tide, instead of draining it off immediately, by digging a hole in the ground. But there are cases in which the blood-vessels become so isolated, that they refuse to yield their morbid excitement to depletion from any outlet, except from themselves. I attended a sailor, in the Pennsylvania hospital, in 1799, who was affected with deafness, attended with a full and tense pulse. I prescribed for it, purging, blisters, and low diet, but without any effect. Perceiving no change in his pulse, nor in his disease from these remedies, I ordered him to lose ten ounces of blood. The relief obtained by this evacuation induced me to repeat it. By means of six bleedings, he was perfectly cured, without the aid of any other remedy.
Bleeding has great advantages over every mode of depleting that has been mentioned.
1. It abstracts one of the exciting causes, viz. the stimulus of blood from the seat of the fever. I have formerly illustrated this advantage of blood-letting, by comparing it to an abstraction of a grain of sand from the eye to cure an opthalmia. The other depleting remedies are as indirect and circuitous in their operation in curing fever, as vomits and purges would be to remove an inflammation of the eye, while the grain of sand continued to irrigate it.
2. Blood-letting is quick in its operation, and may be accommodated to the rapidity of fever, when it manifests itself in apoplexy, palsy, and syncope.
3. It is under the command of a physician. He may bleed when and where he pleases, and may suit the quantity of blood he draws, exactly to the condition of his patient's system. 
4. It may be performed with the least attendance of nurses or friends. This is of great importance to the poor at all times, and to the rich during the prevalence of mortal epidemics.
5. It disturbs the system much less than any of the other modes of depleting, and therefore is best accommodated to that state of the system, in which patients are in danger of fainting or dying upon being moved.
6. It is a more delicate depleting remedy than most of those which have been mentioned, particularly vomits, purges, and a salivation.
7. There is no immediate danger to life from its use. Patients have sometimes died under the operation of vomits and purges, but I never saw nor heard an instance of a patient's dying in a fainty fit, brought on by bleeding.
8. It is less weakening, when used to the extent that is necessary to cure, than the same degrees of vomiting, purging and sweating.
9. Convalescence is more rapid and more perfect after bleeding, than after the successful use of any other evacuating remedies.
By making use of blood-letting in fevers, we are not precluded from the benefits of other evacuating remedies. Some of them are rendered more certain and more effectual by it, and there are cases of fever, in which the combined or successive application of them all is barely sufficient to save life.
To rely upon any one evacuation remedy, to the exclusion of the others, is like trusting to a pair of oars in a sea voyage, instead of spreading every sail of a ship.
I suspect the disputes about the eligibility of the different remedies which have been mentioned, have arisen from ignorance that they belong to one class, and that they differ only in their force, and manner of operation. Thus the physicians of the last century ascribed different virtues to salts of different names, which the chemists of the present day have taught us are exactly the same, and differ only in the manner of their being prepared.
Having replied to the principle objections to blood-letting, and stated its comparative advantages over other  modes of depletion, I proceed next to mention the circumstances which should regulate the use of it. These are,
I. The state of the pulse.
The following state of the pulse indicates the necessity of bleeding.
1. A full, frequent and vigorous pulse without tension, such as occurs in the yellow fever, gout and apoplexy. I have called it the synochus fortis pulse.
2. A full, frequent, and tense pulse, such as occurs in the pulmonary, rheumatic, gouty, phrenitic, and maniacal states of fever.
3. A full, frequent, and jerking pulse, without tension, such as frequently occurs in the vertiginous, paralytic, apoplectic, and hydropic states of fever.
4. A small, frequent, but tense pulse, such as occurs in the chronic pulmonary, and rheumatic states of fever.
5. A tense and quick pulse, without much preternatural frequency. This state of pulse is common in the yellow fever.
6. A slow and tense pulse, such as occurs in the apoplectic, hydrocephalic, and malignant states of fever, in which its strokes are from 60 to 9, in a minute.
7. An uncommonly frequent pulse, without much tension, beating from 120 to 170 or 180 strokes in a minute.
This state of pulse occurs likewise in the malignant states of fever.
8. A soft pulse, without much frequency or fulness. I have met with this state of the pulse in affections of the brain, and in that state of pulmonary fever which is known by the name of pneumonia notha. It sometimes, I have remarked, becomes tense after bleeding.
9. An intermitting pulse.
10. A depressed pulse.
11. An imperceptible pulse. The slow, intermitting, depressed, and imperceptible states of the pulse are supposed exclusively to indicate congestion in the brains. But they are all, I believe occasioned likewise by the great excess of stimulus acting upon the heart and arteries. A pulse more tense in one arm than in the other, I have generally found to attend a morbid state of the brain. Much yet remains to be known of the signs of a disease in the  brain, by the state of the pulse; hence Mr. Hunter has justly remarked, that "In inflammation of the brain, the pulse varies more than in inflammations of any other part; and perhaps we are led to judge of inflammation there, more from other symptoms than the pulse." (Treatise on Inflammation, chap. iii, 9.)
The slow, uncommonly frequent, intermitting, and imperceptible states of the pulse, which require bleeding, may be distinguished from the same states of the pulse, which arise from an exhausted state of the system, and that forbid bleeding, by the following marks:
1. They occur in the beginning of a fever.
2. They occur in the paroxysms of fevers which have remissions and exacerbations.
3. They sometimes occur after blood-letting, from causes formerly mentioned.
4. They sometimes occur, and continue during the whole course of an inflammation of the stomach and bowels. And,
5. They occur in relapses, after the crisis of a fever.
The other stages of the pulse indicate bleeding in every stage of fever, and in every condition of the system. I have taken notice, in another place, of the circumstances which render it proper in the advanced stage of chronic fever.
If all the states of the pulse which have been enumerated indicate bleeding, it must be an affecting consideration to reflect, how many lives have been lost, by physicians limiting the use of the lancet only to the tense or full pulse!
I wish it comported with the proposed limits of this essay to illustrate and establish, by the recital of cases, the truth of these remarks, upon the indications of bleeding from the pulse. It communicates much more knowledge of the state of the system than any other sign of disease. Its frequency (unconnected with its other states,) being under the influence of diet, motion, and the passions of the mind, is of the least consequence. In counting the number of its strokes, we are apt to be diverted from attending to its irregularity and force; and in these, it should always be remembered, fever chiefly consists. The knowledge acquired by attending to these states of the pulse is so definite and useful, and the circumstances which seduce from a due attention to them are so erroneous in their indications, that I have sometimes wished the Chinese custom  of prescribing, from feeling the pulse only, without seeing or conversing with the patient, were imposed on all physicians.
To render the knowledge of the indications of blood-letting, from the state of the pulse, as definite and correct as possible, I shall add, for the benefit of young practitioners, the following directions for feeling it.
1. Let the arm be placed in a situation in which all the muscles which move it shall be completely relaxed; and let it, at the same time, be free from the pressure of the body upon it.
2. Feel the pulse, in all obscure or difficult cases, in both arms.
3. Apply all the fingers of one hand, when practicable, to the pulse. For this purpose, it will be most convenient to feel the pulse of the right hand with your left, and of the left hand with your right.
4. Do not decide upon blood-letting, in difficult cases, until you have felt the pulse for some time. The Chinese physicians never prescribe until they have counted 49 strokes.
5. Feel the pulse at the intervals of four or five minutes, when you suspect its force has been varied by any circumstances not connected with the disease, such as emotions of the mind, exercise, eating, drinking, and the like.
6. Feel the pulsations of the arteries in the temples and in the neck, when the pulse is depressed or imperceptible in the wrists.
7. Request silence in a sick room, and close your eyes, in feeling a pulse in difficult cases. By doing so, you will concentrate the sensations of your ears and eyes, in your fingers.
In judging of the states of the pulse which have been enumerated, it will be necessary always to remember the natural differences, in its frequency and force, in old people and children; also in the morning and evening, and in the sleeping and waking states of the system.
Much yet remains to be known upon this subject. I have mentioned the different states of the pulse which call for bleeding, but it is more difficult to prescribe it, when the pulse imparts no signs of the disease. In  general it may be remarked when the disease is recent, the part affected important to life, and incapable of sustaining violent morbid action long, without danger of disorganization, where pain is great, and respiration difficult, where there is redness in the face, and a watery, lively, or suffused eye, the pulse may be disregarded in the use of the lancet. To these signs, Dr. Sydenham adds, in the history of the case of a lady in whom the pulse gave no indication of the force of the disease, "a red colour in the cheeks; drops of blood issuing from the nose, no diminution of the heat of the body after bleeding and the existence of an inflammatory constitution of the atmosphere." (Wallis's edition, vol. i, 134.)
But to return.
II. Regard should be had to the character of the reigning epidemic, in deciding upon blood-letting. If the prevailing fever be of a highly inflammatory nature, bleeding may be used with more safety, in cases where the indications of it from the pulse are somewhat doubtful. The character of the previous epidemic should likewise direct the use of the lancet. The pestilential fever which followed the plague in London, in 1665, Dr. Sydenham says, yielded only to blood-letting. It is equally necessary in all the febrile diseases which succeed malignant fevers.
III. Regard should be had to the season of the year, and to the state of the weather. It is more copiously indicated in the winter and spring, than in the summer and autumn in middle latitudes, and Dr. Hillary and Dr. Huxham both say, it is more necessary in dry, than in moist weather.
The words of Dr. Huxham upon this subject are as follow, "Diseases even of the same species (as I have constantly observed) require much larger bleeding, and the sick bear it much better in dry weather, when the barometer stands high, than when a hot moist air almost destroys the tone of the vessels. This is constantly observable even in diseases of the breast." (Observations upon the air, and Epidemic Diseases, preface, page xxviii.) The advantages  of copious bleeding in the yellow fever of 1793 when the weather was uncommonly dry, confirms the truth of the remarks of those excellent practical physicians.
IV. The constitution of the patient, and more especially his habits with respect to blood-letting, should be taken into consideration, in prescribing it. If he be plethoric, and accustomed to bleeding in former indispositions, it will be more necessary, than in opposite states and habits of the system. Nature will expect it.
V. The corpulency of a patient should regulate the use of the lancet. A butcher of great observation informed me, that a fat ox did not yield more than from one half, to one third of the quantity of blood of a lean one, of the same size bone, and it is well known that the loss of a small quantity of blood, after cutting the head off a fowl, is always a sign of its being fit for the table. The pressure of fat upon the blood-vessels produces the same effects in the human species that it does in those animals; of course, less blood should be drawn from fat, than from lean people, under equal circumstances of disease.
VI. As persons have more or less blood in their vessels, according to their size, less blood should be drawn, under equal circumstances, from small than large people.
VII. Regard should be had to the age of adults in prescribing bleeding. In persons between fifty and sixty years of age, for reasons formerly mentioned, more blood may be drawn than in middle life, in similar diseases. In persons beyond 70, it will be necessary to regulate the quantity to be drawn by other signs than the pulse, or the appearances of the blood, the former being generally full, and sometimes tense, and the latter often putting on the sign of the second grade of morbid action formerly described.
VIII. Regard should be had to the country or place from which persons affected with fevers have arrived, in prescribing the loss of blood. Fevers, in America, are more inflammatory than fevers, in persons of equal rank, in Great-Britain. A French physician once said, it was safer to draw a hogshead of wine from a Frenchman's veins, than a quarter of a hundred pounds of beef  from an Englishman's, meaning to convey an idea of the difference in the grades of morbid or inflammatory action in the diseases of the inhabitants of Frane and England, and of the difference in the quantity of blood proper to be drawn in each of them. A similar difference exists between the grades of fever in Great-Britain and America. From a want of attention to this circumstance, I saw a common pleurisy end in an abscess of the lungs, in a sea captain, in the city of London, in the year 1769, who was attended by a physician of the first reputation in England. He was bled but once. His pulse and American constitution called for the loss of 50 to 60 ounces of blood. My former pupil Dr. Fisher in a letter from the university of Edinburgh dated in the winter of 1795, informed me, that he had cured several of his American fellow students of fevers, contrary to the general prejudices and practice in that city, by early bleeding, in as easy and summary a way as he had been accustomed to see them cured in Philadelphia by the same remedy. It is not less true, and worthy of attention of an American physician, that the diseases of new comers into the United States from Great-Britain, Ireland and other European countries, require more bleeding than the natives or old settlers, under equal circumstances of disease. This fact struck the late Dr. Reynolds in a very forcible manner, in his extensive practice among his newly arrived fellow citizens from Ireland. The remark is founded in reason, and it is to be wished, those European physicians who charge their patients when they are about to emigrate to America, "never to be bled," would consider how much the change which the stimulating impressions of a new climate, diet, company, and often of employments, make upon the system, is opposed to their advice.
IX. Regard should be had to the structure and situation of the parts diseased with febrile action. The brain, from its importance, to all the functions of life, the rectum, the bladder, and the trachea, when inflamed, and the intestines, when strangulated, from their being removed so much out of the influence of the great circulation, all require more copious bleeding than the same degrees of disease in the lungs, and some other parts of the body. 
X. After blood-letting has been performed, the appearances of the blood should be attended to, in order to judge of the propriety of repeating it. I shall briefly describe these appearances, and arrange them in the order in which they indicate the different degrees of inflammatory diathesis, beginning with the highest.
1. Dissolved blood. It occurs in the malignant states of fever. I have seen it several times in the pleurisy, and have once heard of it in a case of gout. I have ascribed this decomposition of the blood to such a violent, or a feeble degree of action in the blood-vessels as to dispose them to a paralytic state. It is generally considered as a signal to lay aside the lancet. If it occurs in the first stage of a fever, it indicates a very opposite practice. By repeated bleedings, the vessels recover their natural action, and the blood becomes resuscitated, or reduced to its original texture. Of this I have had frequent experience, since the year 1793. It required three successive bleedings to restore the blood from a dissolved, to a coagulable state, in Mr. Benton. It afterwards became very sizy. If this dissolved blood appear towards the close of a malignant fever, no other benefit than the protraction of life for a day or two, or an easy death, can be expected from repeating the bleeding, even though it be indicated by a tense pulse; for the viscera are generally so much choaked by the continuance of violent action in the blood-vessels, that they are seldom able to discharge the blood which distends them, into the cavity in vessels, which is created by the abstraction of blood from a vein. There is some variety in the appearance of this state of the blood, which indicates more or less violent pressure upon the blood-vessels. It threatens most danger to life when it resembles molasses in its consistence. The danger is less when the part which is dissolved occupies the bottom of the bowl, and when its surface is covered with a sizy pellicle or coat. I have said the blood is sometimes dissolved from a too feeble action of the blood-vessels upon it. We observe this in the scurvy and in the lowest grade of typhus fever. It is restored in these cases to its natural consistence by means of stimulating remedies. To this account of the morbid state of the blood, it may not be improper to add, that Dr. Stoll found it coagulated in the  veins of an epileptic patient, and that Morgagni mentions the case of a girl in whom in the blood was cold. She had at the same time no sense of the coldness of any part of her body. By means of stimulants, she was recovered.
Does not the restoration of the blood from its disorganized state, by means of bleeding, suggest an idea of a similar change being practicable in the solids, when they are disorganized by disease? And are we not led hereby to an animating view of the extent and power of medicine?
2. Blood of a scarlet colour, without any separation into crassamentum or serum, indicates a second degree of morbid action. It occurs likewise in the malignant state of fever. It is called improperly dense blood. It occurs in old people.
3. Blood in which part of the crassamentum is dissolved in the serum, forming a resemblance to what is called the lotura carnium, or the washings of flesh in water.
4. Serum of a clear red, or green colour. The violence and danger of fevers in which the serum of the blood assumes the latter colour, is taken notice of by Dr. Huxham. (On Air and Epidemics, vol. 1, p. 129.)
5. Crassamentum sinking to the bottom of a bowl in yellow serum.
6. Crassamentum floating in serum, which is at first turbid, but which afterwards becomes yellow and transparent, by depositing certain red and fiery particles of the blood in the bottom of the bowl.
7. Sizy blood, or blood covered with a buffy coat. The more the crassamentum appears in the form of a cup, the more inflammatory action is said to be indicated by it. This appearance of the blood occurs in all the common states of inflammatory fever. It occurs too in the mild state of malignant fevers, and in the close of such of them as have been violent. It is not always confined to the common inflammatory state of the pulse, for I have observed it occasionally in most of the difficult states of the pulse which have been described. The appearance of this buffy coat on the blood in the yellow fever is always favourable. It shows the disease to be tending from an  uncommon to a common degree of inflammatory diathesis. It has been remarked, that bood which resembles claret in its colour, while flowing, generally puts on, when it cools, a sizy appearance. Blood which assumes a paler red colour near the edges of the bowl, than that which is in the middle of the bowl into which it is flowing, is likewise generally sizy.
It would seem, from these facts, that the power of coagulation in the blood was lessened in an exact ratio to the increase of action upon the blood-vessels, and that it was increased in proportion to the diminution of that action, to that degree of it, which constitutes what I have called common inflammatory action.
Here, as upon a former occasion, we may say with concern, if bleeding be indicated by all the appearances of the blood, which have been enumerated, how many lives have been lost by physicians limiting the use of the lancet to those cases only, where the blood discovered an inflammatory crust!
It would be a digression from the subject now under consideration, or I would add in this place some remarks upon what is called the vitality of the blood. I shall only mention, that I have for many years taught in my physiological lectures that the blood in the healthy state appears to be like the bones and tendons, animalized only, and like those parts of the body, it becomes animated by the stimulus of disease. The more sizy it becomes the more it partakes of an animated quality. Its cupped appearance indicates its having assumed a muscular nature. It is in this animated state of the fibrin only, that it forms those membranes which succeed inflammation in different parts of the body.
More to come
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