liv THE LIFE OF HARVEY. 



nothing more than the accredited opinion that the blood was 

 in motion \vithin the vessels, particularly the veins of the body. 

 In ancient times, indeed, the veins were regarded, as they are 

 esteemed by the vulgar at the present hour, as the principal 

 vessels of the body ; they only were once believed to contain true 

 blood; the arteries were held to contain at best but a little blood, 

 different from that of the veins, and mixed accidentally in some 

 sort with the vital spirits, of which they were the proper conduits. 



In former times, farther, times anterior to Harvey whether 

 more remotely or more nearly, the liver, as the organ of the 

 hsemapoesis, was regarded as the source of all the veins, i. e. of 

 all the proper blood-vessels ; the heart, as the generator of heat 

 and the vital spirits, was viewed as the mere cistern of the blood, 

 whence it was propelled by the act of inspiration, and whither it 

 reverted during the act of expiration, its flow to this part of the 

 body or to that, being mainly determined by certain excitations 

 there inherent or specially set up. By and by, however, the liver 

 was given up as the origin of the venous system generally; but 

 such anatomists as Jacobus Sylvius, Realdus Columbus, Bartho- 

 lomasus Eustachius, and Gabriel Fallopius, may be found op- 

 posing Vesalius in regard to the origin of the vena cava, and 

 asserting that it takes its rise from the liver, not from the heart, 

 as the great reformer in modern anatomy had maintained. 



In the progress of anatomical investigation, the valves in the 

 interior of the heart, at the roots of the two great cardiac 

 arterial trunks, and in the course of the veins at large, were 

 perceived and their probable uses and actions canvassed. The 

 general and prevalent notion was that they served to break or 

 moderate the force of the current in the interior of the vessels 

 or parts where they were encountered ; though Berengarius of 

 Carpi, 1 in describing the cardiac valves, had already said that 

 the effect of the tricuspid valves, between the right auricle and 

 ventricle, must be to prevent the blood in the former cavity 



1 Comment, super Anatomiam Muudini, 4to, Bonon. 1521. 



