Proceedings of the Ohio State Academy of Science 445 



described before, thereby claiming the discovery for himself. 

 There can be no doubt but that Columbus had known of this 

 new theory for Servetus is known to have sent a copy of his 

 book to Padua where Columbus was professor of anatomy and 

 had studied for some time with Vesalius. He may be excused 

 for this claim under the circumstances for if he had referred 

 to Servetus' work and agreed with him he would doubtless 

 have suffered the same fate at the stake, for if he had recog- 

 nized Servetus as a physiologist he would have been held as 

 respecting him as a theologian. There may be, however, some 

 question as to whether Columbus was familiar with the works 

 of Servetus but there can be no doubt about his understand- 

 ing the pulmonary circulation as well as could be understood 

 without knowing of the capillaries. 



Columbus says on the heart and arteries : "Cavities, that 

 is, two ventricles, are present in the heart, not three as Aris- 

 totle thought. Of these one is on the right side, and the other 

 on the left. The right is much larger than the left. The 

 right contains the natural blood, but the left the vital blood. 

 It is very interesting to observe that the substance of the 

 lieart surrounding the right ventricle is very thin but on the 

 left side is very thick ; and this is so arranged on the one hand 

 to keep up the balance and on the other to prevent the vital 

 blood which is exceedingly thin from transuding out of the 

 heart. Between these ventricles is placed the septum through 

 which almost all authors think there is a way open from the 

 right to the left ventricle ; and according to them the blood 

 is in the transit rendered thin by the generation of the vital 

 spirits in order that the passage may take place more easily. 

 But these make a great mistake; for the blood is carried by 

 the artery-like vein to the lungs and being there made thin 

 is brought back thence together with air by the vein-like ar- 

 tery to the left ventricle of the heart. This fact no one has 

 hitherto observed or recorded in writing; yet it may be most 

 readilv observed by anyone." He refers to the vein-like 

 arterv in the following terms: "Anatomists, not very wise, 



