equalities in the balance of the system, which may have little or no effect unless when the system becomes preternaturally plethoric; and, therefore, that, in all cases, the preventing or removing of the plethoric state of the system, will be a chief means of preventing the first attacks, or the returns of hæmorrhagy. It now, therefore, remains to explain, how the plethoric state of the system is to be prevented or removed.

783. The fluids of the human body are in con. tinual waste by the excretions, but are commonly replaced by the aliments taken in and if the quantity of aliments in any measure exceeds that of the excretions, an increase of the quantity of the fluids of the body, or, in other words, a plethoric state, must necessarily arise. This, to a certain degree, is requisite for the growth of the body; but, even then, if the proportion of the aliments to the excretions, be greater than is suited to the growth of the body, and more certainly still, if after the growth is completed, when an equality between the ingesta and the excreta should be established, the disproportion still continue, a preternaturally plethoric state must arise. In both cases, it is evident, that the plethora must be prevented or corrected by adjusting the ingesta and excreta to each other; which generally may be done, either by diminishing the ingesta, or by increasing the excreta. The former may be effected

by the management of diet, the latter by the management of exercise.

784. The ingesta may be diminished, either by giving aliment in less quantity than usual, or by giving aliments of a less nutritious quality, that is, aliments of a substance, which, under the same bulk and weight, contain less of a matter cap-, able of being converted into animal fluids, and more of a matter ready to pass off by the excretions, and consequently less of a matter to be rétained and accumulated in the vessels.

The choice of aliments suited to these purposes, must be left to be directed by the doctrines of the Materia Medica.

785. The increasing of the excreta, and thereby diminishing the plethoric state of the system, is to be obtained by increasing the exercise of the body; and generally for adjusting the balance between the ingesta and excreta, and thereby obviating the plethoric state, it is necessary that exercise, in a due measure, be very constantly employed.

786. The observing abstinence, and the employment of exercise, for obviating or removing the plethoric state of the body, were formerly considered pretty fully, when treating of the Gout, (548 to 552); so that the less is necessary to be

said here; and it is now only requisite to observe, that the same doubts, as in cases of the gout, do not occur here with regard to the safety of those measures, which, in a plethoric state of the body disposing to hæmorrhagy, are always admissible and proper. Here, however, it is to be observed, that some choice in the mode of exercise is necesSary, and that it should be different according to the particular determinations which may happen to prevail in the system. In general, in the case of plethora disposing to hæmorrhagy, bodily exercise will always be hazardous, and gestation more commonly safe.

787. Artificial evacuations may be employed to diminish the plethoric state of the body; and when, at any time, it has become considerable, and immediately threatens a disease, these evacuations should be made to the quantity that the symptoms seem to require. But it is constantly to be attended to, that blood-lettings are improperly employed to prevent a plethora, as they have a tendency to increase it (721); and as they require to be often repeated, and are thereby apt to induce a habit which may be attended with much danger.

788. While a plethora, and thereby the predisposition to haemorrhagy, is avoided, or removed, the other measures necessary for preventing the occurrence of this, are those for avoiding the re

mote causes. These have been enumerated in 775; and the means of avoiding them, so far as within our power, are sufficiently obvious.

789. Having thus mentioned the means of preventing either the first attacks, or the recurrence of hæmorrhagy; I must next say how it is to be managed when it has actually come on.

790. When an hæmorrhagy has come on which appears to have arisen from a preternaturally plethoric state, or from some change in the balance of the sanguiferous system, no measures are to be immediately taken for suppressing it: as we may expect, that, when the quantity of blood necessary for the relief of the system is poured out, the effusion will spontaneously cease.

791. In many cases, however, it may be suspected, that the quantity of blood poured out, is not exactly in proportion to the necessities of the system, either for relieving a general plethora or a particular congestion, but that it is often to a greater quantity than these require. This we suppose to happen in consequence of an inflammatory diathesis prevailing, and of a febrile spasm being formed; and therefore it is in many cases proper, as well as for the most part safe, to moderate the evacuation, and, when it threatens to go to excess, to suppress it altogether,

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792. An hæmorrhagy may be moderated by avoiding any irritation that might concur to increase it; so that every part of the antiphlogistic regimen is to be observed; in particular external heat, both as it rarifies the fluids, and stimulates the solids, is to be carefully avoided and it is probable, that in all cases an hæmorrhagy may be safely moderated by cool air applied, and cold drink exhibited.

793. A second means for the same purpose, is, the use of refrigerant medicines, and particularly of acids and nitre.

794. A third means which has been frequently employed, is that of blood-letting. The propriety of this practice may be doubtful, as the quantity of blood poured out by the hæmorrhagy, may be supposed to answer the purpose of an evacuation in any other way and I am ready to allow, that the practice has been often superfluous, and sometimes hurtful, by making a greater evacuation than was necessary or safe. At the same time, I apprehend it is not for the mere purpose of evacuating, that blood-letting is to be practised in the cure of hæmorrhagy; but that it is further necessary for taking off the inflammatory diathesis which prevails, and the febrile spasm that has been formed. Accordingly, in the case of hæmorrhagy, when the pulse is not only frequent,

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