vi CIRCULATION OF BLOOD: ITS DISCOVERY 167 



Riolan, Bartholin, and others indicates that he prudently avoided 

 a dispute in which he had much to lose and nothing to gain. 

 Willis, in order to explain Harvey's action, has recently advanced 

 the view that he was a freethinker, and anti-Trinitarian like 

 Servetus and Cesalpinus, whose works he certainly knew, and 

 with whose views he fully sympathised. As court physician to 

 Charles I., the severe persecutor of Anabaptists and anti- 

 Trinitarians, he could not own to these tendencies without grave 

 danger. Hence, being indisposed to martyrdom, he kept silence. 

 It is obvious, however, that while this might explain his attitude 

 towards Servetus, it could not apply in any way to Cesalpinus, who 

 was the Pope's chief physician, and is known to have performed the 

 necropsy of Filippo Neri, in describing which his orthodoxy is only 

 too apparent. 



^N evertheless, Harvey's little book of 72 pages which came out 

 at Frankfurt in 1628, Exercitatio anatomica de motu cordis et 

 sanguinis in animalibus, is unmistakably the masterpiece of a 

 man of genius. 



Even now, after more than two and a half centuries of scientific 

 discovery, this opuscidum aureum, as Haller termed it, arouses 

 the admiration of the reader by its lucid ideas, and the logical 

 arrangement of its observations, which were all founded on vivi- 

 section. With the exception of a few inaccuracies and errors every- 

 thing it contains is well observed and reasoned, and it may still serve 

 as the introduction to a deeper study of this interesting subject. 



After exposing the cardiac region in the living animal, Harvey 

 noted that the heart is alternately in a state of motion and of rest. 

 During systole it rises and strikes the thoracic wall with its 

 apex ; it contracts in all its parts, more particularly in the lateral 

 portions ; it hardens, like the muscles of the upper arm when they 

 contract ; and in cold-blooded animals it becomes pale when the 

 blood is emptied out of its cavity. The diastole or pulse of the 

 arteries coincides with the heart's systole. When the heart stops, 

 the arteries cease to pulsate. On opening an artery the blood 

 gushes out at every systole. Hence at the moment of systole the 

 blood is forced into the arteries, and cannot flow back, because 

 the valves hinder the reflux. 



The auricles contract and relax together like the ventricles, but 

 before them. The movement appears to start from the auricles 

 and then reaches the ventricles. When the heart dies the left 

 ventricle is the first to stand still, then follows the left auricle, 

 then the right ventricle, the ultimum moriens being, as noted by 

 Galen, the right auricle. If the apex of the heart be cut when the 

 right auricle alone is contracting, the blood is seen to gush out at 

 every beat. The blood, therefore, reaches the ventricles in conse- 

 quence of the contraction of the auricles, and not by aspiration 

 due to distension of the ventricles. 



