70 MOTION OF THE 



there is nothing, as Aristotle says, 1 which can be of service 

 either to it or aught that depends on it. And hence, by the 

 way, it may perchance be wherefore grief, and love, and envy, 

 and anxiety, and all affections of the mind of a similar kind 

 are accompanied with emaciation and decay, or with cacochemy 

 and crudity, which engender all manner of diseases and con- 

 sume the body of man. For every affection of the mind that 

 is attended with either pain or pleasure, hope or fear, is the cause 

 of an agitation whose influence extends to the heart, and there in- 

 duces change from the natural constitution, in the temperature, 

 the pulse and the rest, which impairing all nutrition in its 

 source and abating the powers at large, it is no wonder that 

 various forms of incurable disease in the extremities and in the 

 trunk are the consequence, inasmuch as in such circumstances 

 the whole body labours under the effects of vitiated nutrition 

 and a want of native heat. 



Moreover, when we see that all animals live through food con- 

 cocted in their interior, it is imperative that the digestion and 

 distribution be perfect; and, as a consequence, that there be a 

 place and receptacle where the aliment is perfected and whence 

 it is distributed to the several members. Now this place is the 

 heart, for it is the only organ in the body which contains blood 

 for the general use ; all the others receive it merely for their 

 peculiar or private advantage, just as the heart also has a supply 

 for its own especial behoof in its coronary veins and arteries ; but 

 it is of the store which the heart contains in its auricles and 

 ventricles that I here speak ; and then the heart is the only 

 organ which is so situated and constituted that it can distribute 

 the blood in due proportion to the several parts of the body, 

 the quantity sent to each being according to the dimensions of 

 the artery which supplies it, the heart serving as a magazine or 

 fountain ready to meet its demands. 



Further, a certain impulse or force, as well as an impeller or 

 forcer, such as the heart, was required to effect this distribution 

 and motion of the blood ; both because the blood is disposed 

 from slight causes, such as cold, alarm, horror, and the like, to 

 collect in its source, to concentrate like parts to a whole, or 

 the drops of water spilt upon a table to the mass of liquid ; 



1 De Part. Animal, iii. 



