Similar directions are given by Avicenna (i, 3, 2), and by Haly Abbas (Theor. v, 12.) Averrhoes gives the sum of the directions laid down by Galen and the other authorities. Strong friction, he says, braces and hardens the body; weak, rarifies and softens; moderate, operates in an intermediate degree. Besides, he adds, hard friction diminishes obesity; moderate, on the other hand, tends to remove emaciation. (Collect. ii, 3.) It was a general practice of the ancients to have recourse to friction in the morning and evening. Oribasius has many excellent observations on this practice. (l. c.) SECT. XIX.—ON VOCIFERATION, OR THE EXERCISE OF THE VOICE. In the exercise of the voice, regular and gentle modulation can contribute nothing to health, but the utterance of louder tones is beneficial, and is therefore to be practised. For, much air being inhaled thus by respiration expands the chest and stomach, and dilates and extends all the pores of the body. Wherefore, even in reading, it promotes the excretion of redundant humours, to those who read in a high tone, by inducing sweats; while in those who read with a moderate tone it promotes the insensible perspiration over the whole frame. For by attenuating the excrementitious matters which are hawked up, the saliva, mucus, and phlegm are discharged and consumed. And to those who stand in need of warming, on account of their frigidity, what mode of relief can be more proper than the action of respiration? Such persons ought therefore to read frequently, and, relaxing the whole body, so as to distend the windpipe and all the other passages of air, endeavour to utter the loudest sounds. And yet we must not have recourse to the exercise of the voice rashly, and without consideration, nor when the system is filled with depraved humours, or the stomach loaded with crudities, lest noxious vapours be thereby distributed over the whole body. * * * * * COMMENTARY. These remarks of our author are very pertinent; But Oribasius has given a more comprehensive view of the subject, from the works of Antyllus. He thus describes the mode of performing vociferation: The bowels being evacuated, the person’s body is to be first rubbed, and then the inferior parts and the face are to be sponged with water. He is to begin talking, at first, in a moderate tone, while at the same time he walks about, and afterwards, straining his voice to a louder tone, he is to repeat certain verses. (Med. Collect. vi.) Plutarch gives nearly the same account of it. He commends vociferation as giving strength to the internal parts, increasing the vital heat, purifying the veins, attenuating the blood, and dispelling the humours. He cautions, however, not to strain the voice to too great a pitch, lest it occasion rupture of any of the vessels. (De Sanit. tuendâ.)