On the Apotherapia or Restorative process, see Galen (Hyg. iii); Oribasius (Med. Collect. vi, 16); and Avicenna (i, 3, 2.) It consisted simply in rubbing the body softly and moderately with oil. According to Galen, the object of it was to relieve the feelings of lassitude, and prevent any bad effects from the exercise. Mercurialis states that, when applied after the bath, it was with the intention of preventing the humidity from being dissipated. Odoriferous ointments and powders were sometimes used instead of the oil. (De Arte gymnast. i; also Baccius de Thermis, 10.) SECT. XVIII.—ON THE KINDS OF FRICTION. Hard friction contracts, and soft relaxes; so that those persons that are relaxed should be rubbed hard, and those that are immoderately constricted, softly; and when, neither in the one state nor the other, it is clear that neither the one mode of friction nor the other should be had recourse to, but as much as possible either extreme ought to be avoided. For much and hard friction diminishes the bulk of the body, whilst, on the other hand, little and soft distends it. If the three different kinds of frictions as to quantity be joined to the same number as to quality, they will produce nine combinations, as is stated below. For one of the kinds, as to quantity, for example _much_, being complicated with the three differences as to quality, I mean the _hard_, the _soft_, and the _moderate_ as to hardness, will produce three combinations; and, again, the _little_ being joined to the other three will produce three more; and the _moderate_ as to quality being complicated with the same three, will produce three more, as is shown below: QUANTITY. QUALITY. Much } { Hard. Much } and { Soft. Much } { Moderate. Little } { Hard. Little } and { Soft. Little } { Moderate. Moderate } { Hard. Moderate } and { Soft. Moderate } { Moderate. * * * * * COMMENTARY. The brief but comprehensive rules of Hippocrates for the application of friction, are thus given in the language of Celsus: “Hippocrates dixit, frictione, si vehemens sit, durari corpus; si lenis, molliri; si multa, minui; si modica, impleri.” Celsus adds, that, according to circumstances, the body may be braced by it, if relaxed; may be softened, if indurated; may have its superfluities expelled, if loaded with plethora; and have nourishment attracted to it, if emaciated. He remarks, that it is mostly applicable in the decline of a disease. His other directions for the application of it are very apposite, (ii, 14.) Pliny delivers the rules of Hippocrates in nearly the same words as Celsus. (Hist. Nat. xxviii, 14.) Our author’s account of friction is taken from Oribasius (Med. Collect. vi), or from Aëtius (iii.) All, however, are indebted to Galen, who handles the subject most scientifically. (Hyg. ii.)