BOOK TWO

[p. 165]through the veins to the principle of vacuum refilling alone, let him explain to us the assumption of food by the hypothetical elements

i.e.let him explain the diadosis.

. For it has been shown that at least in relation to these there is no question of the refilling of a vacuum being in operation, and especially where the parts are very attenuated. It is worth while listening to what Erasistratus says about these cases in the second book of his "General Principles": "In the ultimate simple [vessels], which are thin and narrow, presentation takes place from the adjacent vessels, the nutriment being attracted through the sides of the vessels and deposited in the empty spaces left by the matter which has been carried away." Now, in this statement firstly I admit and accept the words "through the sides." For, if the simple nerve were actually to take in the food through its mouth, it could not distribute it through its whole substance; for the mouth is dedicated to the psychic pneuma

"Spiritus animalis"; cf. p. 152, note 1. The nutriment was for the walls of the vessels, not for their cavities. cf. p. 319, note 3

. It can, however, take it in through its sides from the adjacent simple vein. Secondly, I also accept in Erasistratus' statement the expression which precedes "through the sides." What does this say? "The nutriment being attracted through the sides of the vessels." Now I, too, agree that it is attracted, but it has been previously shown that this is not through the tendency of evacuated matter to be replaced.

PART 7

Let us, then, consider together how it is attracted. How else than in the way that iron is attracted by