As the accession of inflammation depends upon a change of the natural action of the vital principle, so does its removal depend upon the reconversion of this into the natural action, which implies activity, or an active state. If, then, we bleed in the end of inflammation, we lessen the powers of the part so much, as to prevent restoration; gangrene, therefore, will take place: Or, if the part be less delicate, and the progress of the action consequently slower, the inflammation may continue stationary for a considerable time, and become chronic, or habitual. This state is not to be cured by bleeding, but will rather be made worse by it. Whenever, then, after inflammation has continued for a length of time, we find, that venesection does not produce the usual abatement; or, whenever, although there be a temporary abatement, the pain increases afterwards to a greater degree, we may be certain our treatment is improper. We likewise find, that the longer bleeding has been delayed, in the beginning of the disease, the sooner must we stop, and the less quantity must we take at a time; because, in this case, the inflammatory action is nearer its termination, and is more ready to produce gangrene, if the parts be delicate, or the action great, or, if otherwise, the inflammatio assuefacta. We are also to refrain from bleeding, when we find that the inflammatory action is about to terminate in another action; as, for instance, the suppurative; because, in the first place, bleeding, in this new action, can do no good, but, by weakening, will do harm; and, secondly, if there be only a tendency to this action, the action not being yet formed, or beginning to form, we may, by bleeding, interrupt the progress of the inflammation, and convert it into a more tedious disease, or the inflammatio assuefacta.
Bleeding has been used, not only as a cure for inflammation, but also as a preventative; but this must be considered as proper, only in particular instances. When, for instance, an wound has been inflicted, or an operation necessarily performed, on a robust person, bleeding immediately, or very soon after it, may be useful; because it will tend to lessen the chance of the natural action being carried so high as to become changed. These people cannot have their action much increased without disease; and, therefore, it is necessary to lessen it, and bring it down to a more proper medium. But there are other cases, where the action is naturally rather too low, and the patient weakly. In these cases, bleeding can do no good, but much harm; because it increases the previous weakness, and makes the inflammation, if it does occur, more dangerous, on account of the little power which there is to support the action. These people even bear bleeding worse than others, when inflammation has actually taken place. It ought never to be practised, in order to reduce the natural action, before disease has taken place; and, after the inflammatory action is induced, it ought to be used cautiously, and only to such an extent, as may be necessary for removing the tendency to immediate bad consequences. It ought, however, to be used very early in the disease; because, in weak people, the action does more harm in a given time, than in the strong; but it ought likewise to be sooner abandoned, otherwise we either hasten mortification, or prevent the act of restoration from taking place.