VASCULAR SYSTEM. 109 



Q. What then is the use of the heart? 



./?. It is purely to give a mechanical impulse to the 

 blood. 



Q. Where do you find this impulsive power greatest? 



A. In that circulation which is the most extensive: the 

 left ventricle has therefore more power than the right. 



Q. Has the heart any influence on the qualities of the 

 blood? 



A. It is not probable that any effect is produced on the 

 blood by the action of the heart other than a more intimate 

 mixture of its particles. 



Q. Can you suppose a case in which the heart could be 

 dispensed with? 



.#. The agency of the heart is required by the extent 

 of the circulations of red and black blood; as these are less 

 extensive, the impulsive influence of the heart will in pro- 

 portion be dispensed with; in no other view can the idea 

 suggested by the question be admitted. 



Q. Is there any motion independent of the heart's im- 

 pulse ? 



A. There is an oscillatory motion as in the branches 

 which terminate in the porta of the liver; this oscillation 

 keeps up circulation in syncope. 



Q. What are the general uses of the circulation with 

 red blood? 



Ji. It supplies the materials for secretion and nutrition. 

 The motion of the arteries which convey red blood is use- 

 ful in aiding functional action. 



Q. Does the red blood furnish the material for secretion 

 to every organ? 



Ji. To all except the liver. 



