CIRCULATION OF THE BLOOD IIS 



deeper tint in the diastole; and almost all things else are 

 seen by which I have already said that the truth I con- 

 tend for is established, only that here everything takes 

 place more slowly, and is more distinct This point in 

 particular may be observed more clearly than the noon- 

 day sun: the vena cava enters the heart at its lower part, 

 the artery quits it at the superior part; the vein being 

 now seized either with forceps or between the finger and 

 the thumb, and the course of the blood for some space 

 below the heart interrupted, you will perceive the part 

 that intervenes between the fingers r id the heart almost 

 immediately to become empty, the blood being exhausted 

 by the action of the heart; at the same time the heart 

 will become of a much paler colour, even in its state of 

 dilatation, than it was before; it is also smaller than at 

 first, from wanting blood: and then it begins to beat more 

 slowly, so that it seems at length as if it were about to 

 die. But the impediment to the flow of blood being re- 

 moved, instantly the colour and the size of the heart are 

 restored. 



If, on the contrary, the artery instead of the vein be 

 compressed or tied, you will observe the part between the 

 obstacle and the heart, and the heart itself, to become 

 inordinately distended, to assume a deep purple or even 

 livid colour, and at length to be so much oppressed with 

 blood that you will believe it about to be choked; but the 

 obstacle removed, all things immediately return to their 

 natural state and colour, size, and impulse. 



Here then we have evidence of two kinds of death: 

 extinction from deficiency, and suffocation from excess. 

 Examples of both have now been set before you, and you 

 have had opportunity of viewing the truth contended for 

 with your own eyes in the heart 



CHAPTER XI 

 THE SECOND POSITION is DEMONSTRATED 



THAT this may the more clearly appear to everyone, I 

 have here to cite certain experiments, from which it seems 



