CIRCULATION OF THE BLOOD. 137 



but which it does not seem expedient to enter upon here. 

 Before long, perhaps, I shall have occasion to lay before the 

 world things that are more wonderful than these, and that are 

 calculated to throw still greater light upon natural philosophy. 



Meantime I shall only say, and, without pretending to de- 

 monstrate it, propound with the good leave of our learned 

 men, and with all respect for antiquity that the heart, with 

 the veins and arteries and the blood they contain, is to be re- 

 garded as the beginning and author, the fountain and original 

 of all things in the body, the primary cause of life ; and this 

 in the same acceptation as the brain with its nerves, organs of 

 sense and spinal marrow inclusive, is spoken of as the one and 

 general organ of sensation. But if by the word heart the mere 

 body of the heart, made up of its auricles and ventricles, be 

 understood, then I do not believe that the heart is the fashioner 

 of the blood ; neither do I imagine that the blood has powers, 

 properties, motion, or heat, as the gift of the heart ; lastly, nei- 

 ther do I admit that the cause of the systole and contraction is 

 the same as that of the diastole or dilatation, whether in the 

 arteries, auricles, or ventricles ; for I hold that that part of the 

 pulse which is designated the diastole depends on another cause 

 different from the systole, and that it must always and every- 

 where precede any systole ; I hold that the innate heat is the 

 first cause of dilatation, and that the primary dilatation is in 

 the blood itself, after the manner of bodies in a state of fermen- 

 tation, gradually attenuated and swelling, and that in the blood 

 is this finally extinguished ; I assent to Aristotle's example of 

 gruel or milk upon the fire, to this extent, that the rising and 

 falling of the blood does not depend upon vapours or exhala- 

 tions, or spirits, or anything rising in a vaporous or aereal shape, 

 nor upon any external agency, but upon an internal principle 

 under the control of nature. 



Nor is the heart, as some imagine, anything like a chauffer 

 or fire, or heated kettle, and so the source of the heat of 

 the blood ; the blood, instead of receiving, rather gives heat to 

 the heart, as it does to all the other parts of the body ; for the 

 blood is the hottest element in the body ; and it is on this ac- 

 count that the heart is furnished with coronary arteries and 

 veins ; it is for the same reason that other parts have vessels, 

 viz., to secure the access of warmth for their due conservation 



