Book 4
22
Herophilus attributes a moving faculty to the nerves, arteries, and muscles, but believes that the lungs are affected only with a natural desire of enlarging and contracting themselves. Farther, there is the first operation of the lungs by attraction of the outward air, which is drawn in because of the abundance of the external air. Next to this, there is a second natural appetite of the lungs; the breast, pouring in upon itself the breath, and being filled, is no longer able to make an attraction, and throws the superfluity of it upon the lungs, whereby it is in turn sent forth by way of expiration; the parts of the body mutually concurring to this function by the alternate participation of fulness and emptiness. So that to lungs pertain four motions;—first, when the lungs receive the outward air; secondly, when the outward air thus entertained is transmitted to the breast; thirdly, when the lungs again receive that air which they imparted to the breast; fourthly, when this air then received from the breast is thrown outwards. Of these four motions two are dilatations, one when the lungs attract the external air, another when the breast dischargeth itself of it upon the lungs; two are contractions, one when the breast draws into itself the air, the second when it expels this which was insinuated into it. The breast admits only of two motions;—of dilatation, when it draws from the lungs the breath, and of contraction, when it returns what it did receive.
Chapter XXIII. OF THE PASSIONS OF THE BODY, AND WHETHER THE SOUL HATH A SYMPATHETICAL CONDOLENCY WITH IT.
