156 Circulation of the Blood 



physicians proving of any avail, he fell in the course of 

 a few years into a scorbutic and cachectic state, became 

 tabid and died. This patient only received some little 

 relief when the whole of his chest was pummelled or 

 kneaded by a strong man, as a baker kneads dough. 

 His friends thought him poisoned by some maleficent 

 influence, or possessed with an evil spirit. His jugular 

 arteries, enlarged to the size of the thumb, looked like 

 the aorta itself, or they were as large as the descending 

 aorta ; they had pulsated violently, and appeared like 

 two long aneurisms. These symptoms had led to trying 

 the effects of arteriotomy in the temples, but with no 

 relief. In the dead body I found the heart and aorta 

 so much gorged and distended with blood, that the 

 cavities of the ventricles equalled those of a bullock's 

 heart in size. Such is the force of the blood pent up, 

 and such are the effects of its impulse. 



We may therefore conclude, that although there may 

 be impulse without any exit, as illustrated in the experi- 

 ment lately spoken of, still that this could not take 

 place in the vessels of living creatures without most 

 serious dangers and impediments. From this, however, 

 it is manifest that the blood in its course does not 

 everywhere pass with the same celerity, neither with the 

 same force in all places and at all times, but that it 

 varies greatly according to age, sex, temperament, habit 

 of body, and other contingent circumstances, external 

 as well as internal, natural or non-natural. For it does 

 not course through intricate and obstructed passages 

 with the same readiness that it does through straight, 

 unimpeded, and pervious channels. Neither does it 

 run through close, hard, and crowded parts, with the 

 same velocity as through spongy, soft, and permeable 

 tissues. Neither does it flow and penetrate with such 

 swiftness when the impulse [of the heart] is slow and 

 weak, as when this is forcible and frequent, in which 

 case the blood is driven onwards with vigour and in 

 large quantity. Nor is the same blood, when it has 



