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 of the other evacuating remedies. By making use of blood-letting in fevers, we are not precluded from the benefits of the 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 evacuating 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 an ignorance that they all 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 principal 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 states of the pulse indicate the necessity of bleeding. 1. A full, frequent, and tense pulse, such as occurs in the pulmonary, rheumatic, gouty, phrenitic, and maniacal states of fever. 2. A full, frequent, and jerking pulse, without tension, such as frequently occurs in the vertiginous, paralytic, apoplectic, and hydropic states of fever. 3. A small, frequent, but tense pulse, such as occurs in the chronic, pulmonary, and rheumatic states of fever. 4. A tense and _quick_ pulse, without much preternatural frequency. This state of the pulse is common in the yellow fever.