to drink, some hours before, hot water, that his superior parts may be moistened; then the injection is to be performed with pure water, if we be content with a gentle medicine; if somewhat more powerful is required, hydromel(22); if a lenient, a decoction of fœnugreek, or ptisan(23), or mallows, in water: if it be intended to restringe, a decoction of vervains(24). Sea-water, or any other water with the addition of salt, is acrid: but both of these are better boiled. A greater degree of acrimony is given by adding either oil, or nitre, or honey also. The more acrid it is, it evacuates the more; but it is not so easy to bear. The injection ought neither to be cold, nor hot; lest it hurt either way. When it is injected, the patient ought to confine himself as much as possible in bed, and not yield immediately to the first stimulus he finds to go to stool; and not till necessity obliges him. And commonly this evacuation by lightning the superior parts mitigates the distemper itself. When a person has fatigued himself by going to stool, as often as he was obliged, he ought to take rest for a little time; and lest he grow faint, even on the same day to take food. The quantity of which ought to be determined by considering the nature of the paroxysm that is expected; or whether there is no danger of any. CHAP. XIII. OF VOMITING. As a vomit even in health is often necessary to persons of a bilious habit; it is likewise so in those distempers, which are occasioned by bile. Upon this account it is necessary to those, that before fevers are distressed with horrors and tremors; to all those, that labour under a cholera; and all, that are attacked with madness, and a concomitant mirth; and those also, who are oppressed with an epilepsy. But if the distemper be acute, as the cholera; if it be a fever, while there are tetani, the rougher medicines are improper, as has been observed above in the article of purging; and it is sufficient to take such a vomit, as I prescribed for people in health. But when distempers are of long standing, and stubborn, without any fever, as an epilepsy or madness, we must use even white hellebore. Which it is not proper to administer in the winter, or summer; it is best in the spring: in the autumn it does tolerably well. Whoever prescribes it, ought first to take care, that the body of his patient be moist. It is necessary to know, that every medicine of this kind, which is given by way of potion, is not always beneficial to sick people, to healthy always hurtful. CHAP. XIV. OF FRICTION.