Concerning friction(25), Asclepiades looking upon himself as the inventor of it, has said so much in that book, which he entitled ‘of general remedies,’ that tho’ he mentions only three things, that, and wine, and gestation, yet he has taken up the greatest part of his treatise upon the first. Now as it is not fit to defraud the moderns of the merit either of their new discoveries or judicious imitations, so it is but just at the same time to assign those things, which were practised among some of the ancients, to their true authors. It cannot indeed be doubted, that Asclepiades has been both fuller and clearer in his directions, when and how friction ought to be used; but he has discovered nothing, which was not comprized in a few words by the most ancient author Hippocrates; who said, that friction, if violent, hardens the body; if gentle, softens it; if plentiful, extenuates; if moderate, increases its bulk: from whence it follows, that it is to be made use of, when a lax body requires to be braced; or to soften one, that is indurated; or to dissipate where the fulness is hurtful; or to nourish that, which is slender and infirm.

Nevertheless, if a person examine more curiously into these different species (which is not here the province of a physician) he will easily understand that the effects of them all proceed from one cause; that is, the carrying off of something. For a part will be bound, when that thing is taken away, the intervention of which had caused it to be lax; and another is softened by removing that, which occasioned the hardness; and the body is filled, not by the friction itself, but by that food, which afterwards makes its way to the skin, relaxed by a kind of digestion(26). And the degree of it is the cause of these effects so widely different.

But there is a great deal of difference betwixt unction, and friction. For it is necessary for the body to be anointed, and gently rubbed even in acute and recent distempers; but this must be done in the time of their remission, and before taking food. But to make use of long friction is not proper, either in acute or increasing disorders; except when the intention of it is to procure sleep in phrenitic patients. This remedy is very agreeable to inveterate distempers, and where they have abated somewhat of their first violence. I am not ignorant that some maintain, that every remedy is necessary for distempers, while they are increasing, not when they are going off spontaneously. But this is not just; for a distemper, though it would come to a period of itself, may notwithstanding be sooner terminated by the application of remedies. The use of which is necessary upon a double account, both that the health may be restored as soon as possible; and that the disorder, which remains, be not irritated again by any slight cause: for a distemper may be less violent, than it has been, and yet not entirely removed; but there may be some remains of it, which the use of remedies may dissipate.

But though friction may be used in the decline of an illness, yet it is never to be practised in the increase of a fever; but if possible, when the body is entirely free of it; if that can’t be done, at least when there is a remission. It ought also to be performed sometimes over the whole body, as when we would have an infirm person take on flesh; sometimes in particular parts, either because the weakness of that part itself, or of some other, requires it. For both inveterate pains of the head are mitigated by the friction of it (yet not during their violence) and any paralytic limb is strengthened by rubbing it: but much more commonly, when one part is pained, a different one is to be rubbed; and particularly, when we want to make a derivation from the upper or middle parts of the body; and with this intention we rub the extremities. And these people are not to be regarded, who prescribe to a certain number, how often a person is to be rubbed: for that is to be estimated from his strength. Thus if one is very weak, fifty times may be sufficient: if of a more robust habit, it may be done two hundred times. And then in different proportions betwixt these two according to the strength. Whence it also happens, that the motion of the hands in friction must be less frequent in a woman than a man; less frequent in a boy or an old man, than a young man. Lastly, if particular parts are rubbed, they require much and strong friction. For the whole body cannot be quickly weakened by a part, and there is a necessity for dissipating as much of the matter as we can, whether the intention be to relieve the part we brush, or another by means of it. But where a weakness of the whole body requires this treatment all over, it ought to be shorter and more mild; so as only to soften the surface of the skin, to render it more apt to receive new matter from fresh nourishment. A patient is known to be in a bad situation, when the surface of his body is cold, and the internal part is hot with a concomitant thirst, as I observed above. But even in this case friction is the only remedy, which, if it have brought out the heat, may make way for the use of some medicine.