Heart and Blood 39 



of blood from the veins to the arteries, that a pulse 

 takes place, and can be heard within the chest. 



The motion of the heart, then, is entirely of this 

 description, and the one action of the heart is the 

 transmission of the blood and its distribution, by 

 means of the arteries, to the very extremities of the 

 body ; so that the pulse which we feel in the arteries 

 is nothing more than the impulse of the blood derived! 

 from the heart. 



Whether or not the heart, besides propelling the 

 blood, giving it motion locally, and distributing it to- 

 the body, adds anything else to it, heat, spirit, per- 

 fection, must be inquired into by and by, and decided 

 upon other grounds. So much may suffice at this 

 time, when it is shown that by the action of the heart 

 the blood is transfused through the ventricles from the 

 veins to the arteries, and distributed by them to all 

 parts of the body. 



So much, indeed, is admitted by all [physiologists], 

 both from the structure of the heart and the arrange- 

 ment and action of its valves. But still they are like 

 persons purblind or groping about in the dark ; and 

 then they give utterence to diverse, contradictory, and 

 incoherent sentiments, delivering many things upon 

 conjecture, as we have already had occasion to remark. 



The grand cause of hesitation and error in this 

 subject appears to me to have been the intimate con- 

 nection between the heart and the lungs. When men 

 saw both the vena arteriosa [or pulmonary artery] and 

 the arteriae venosse [or pulmonary veins] losing them- 

 selves in the lungs, of course it became a puzzle to 

 them to know how or by what means the right 

 ventricle should distribute the blood to the body, or 

 the left draw it from the venae cavae. This fact is 

 born witness to by Galen, whose words, when writing 

 against Erasistratus in regard to the origin and use of the 

 veins and the coction of the blood, are the following : 5 



1 De Placitis Hippocratis et Platonis, vi. 



