The pulsation of the heart and arteries was regarded by Aristotle as a sort of ebullition in which the liquids were inflated by the vital or innate heat, the fires of which were cooled by the pneuma taken in by the lungs and carried to the heart by the pulmonary vessels.
(29) De Generatione Animalium, Oxford translation, Bk.

II, Chap.

6, Works V, 743 a.
In Vol.

IV of Gomperz' "Greek Thinkers," you will find an admirable discussion on Aristotle as an investigator of nature, and those of you who wish to study his natural history works more closely may do so easily--in the new translation which is in process of publication by the Clarendon Press, Oxford.

At the end of the chapter "De Respiratione" in the "Parva Naturalia" (Oxford edition, 1908), we have Aristotle's attitude towards medicine expressed in a way worthy of a son of the profession: "But health and disease also claim the attention of the scientist, and not merely of the physician, in so far as an account of their causes is concerned.