158 Circulation of the Blood 



the fact that in almost every affection, appetite, hope, 

 or fear, our body suffers, the countenance changes, and 

 the blood appears to course hither and thither. In 

 anger the eyes are fiery and the pupils contracted ; 

 in modesty the cheeks are suffused with blushes ; in 

 fear, and under a sense of infamy and of shame, the 

 face is pale, but the ears burn as if for the evil they 

 heard or were to hear ; in lust how quickly is the 

 member distended with blood and erected ! But, above 

 all, and this is of the highest interest to the medical 

 practitioner, how speedily is pain relieved or removed 

 by the detraction of blood, the application of cupping- 

 glasses, or the compression of the artery which leads 

 to a part? It sometimes vanishes as if by magic. 

 But these are topics that I must refer to my " Medical 

 Observations," where they will be found exposed at 

 length and explained. 



Some weak and inexperienced persons vainly seek 

 by dialectics and far-fetched arguments, either to upset 

 or establish things that are only to be founded on 

 anatomical demonstration, and believed on the evidence 

 of the senses. He who truly desires to be informed 

 of the question in hand, and whether the facts alleged 

 be sensible, visible, or not, must be held bound either 

 to look for himself, or to take on trust the conclusions 

 to which they have come who have looked ; and indeed 

 there is no higher method of attaining to assurance 

 and certainty. Who would pretend to persuade those 

 who had never tasted wine that it was a drink much 

 pleasanter to the palate than water ? By what reason- 

 ing should we give the blind from birth to know that 

 the sun was luminous, and far surpassed the stars in 

 brightness ? And so it is with the circulation of the 

 blood, which the world has now had before it for so 

 many years, illustrated by proofs cognizable by the 

 senses, and confirmed by various experiments. No 

 one has yet been found to dispute the sensible facts, 

 the motion, efflux and afflux of the blood, by like 



