Proceedings of the Ohio State Academy of Science l\1 



made the veins hollow for the sake of their function tliat like 

 streams they might pervade the body." Although he make> 

 great claims for his discovery he failed to appreciate the im- 

 portance of it, as many did after his time. 



Andreas Caesalpinus differed greatly from Columbus. 

 Columbus lacked culture. His education was C(Mnparatively 

 limited. \'esalius refers to him as the smalterer. The exact 

 reyerse of this was Caesalpinus. lie was versed in all of tho 

 knowledge of his time. Born in 151!); we find him prt)fessi)r 

 nf medicine at Pisa from lotvT to l.")!)2. lie was an ardent fol- 

 lower of .\rist()tle's jjhilosophy. He was a naturalist, for we 

 find him teaching botany as well as medicine at Pisa. Being 

 more of a philosopher than a naturalist he was inclined to 

 dispute everything. He went so far as to not only dispute all 

 that Galen said but to hold that all that Galen opposed was 

 correct. He understood the working of the valves of the 

 heart. "For the membranes are so placed at the orifices that 

 they are opened when the heart is dilated and are closed when 

 the heart is contracted." He still holds to the idea of the 

 spirits and the two kinds of blood. He associated the ])ulsc- 

 in the arteries with the beat of the heart and explained the 

 working of the heart correctly in reeci\ing ;incl discharging 

 the blood. He notices that the arteries expand when the 

 heart contracts and that the x'alves are so placed that the blood 

 can not get back from the arteries when the heart relaxes. 

 "If therefore the arteries were dilated and constricted at tlie 

 same time as the heart, it would follow that thev would be 

 dilated at the time when the material tilling tliem from tin- 

 heart was denied them, and constricted at a time when ma- 

 terial was flowing itito them from it. P)Ut it is manifest th;it 

 this is impossible." He is the first to grasp tlie idea that the 

 l)lood is discharged from the heart into the arteries and that 

 the heart receives the blood from the veins, not only from the 

 pulmonarv vein but also from the \enae caxae. He seems to 

 uet the idea of a connection of the arteries witli the \eins in 



