24 NATURAL HISTORY. 



strength robbeth and devoureth the nourishment 

 when they have drawn it : as great fishes devour 

 little. 



Experiments in consort touching purging medicines. 



36. The operation of purging medicines, and the 

 causes thereof, have been thought to be a great 

 secret ; and so according to the slothful manner of 

 men, it is referred to a hidden propriety, a specifical 

 virtue, and a fourth quality, and the like shifts of 

 ignorance. The causes of purging are divers : all 

 plain and perspicuous, and thoroughly maintained 

 by experience. The first is, that whatsoever can 

 not be overcome and digested by the stomach, is by 

 the stomach either put up by vomit, or put down to 

 the guts ; and by that motion of expulsion in the 

 stomach and guts, other parts of the body, as the 

 orifices of the veins, and the like, are moved to expel 

 by consent. For nothing is more frequent than mo 

 tion of consent in the body of man. This surcharge 

 of the stomach is caused either by the quality of the 

 medicine, or by the quantity. The qualities are 

 three : extreme bitter, as in aloes, coloquintida, &c. 

 loathsome and of horrible taste, as in agaric, black 

 hellebore, &c. and of secret malignity, and disagree 

 ment towards man s body, many times not appearing 

 much in the taste, as in scammony, mechoachan, an 

 timony, &c. And note well, that if there be any 

 medicine that purgeth, and hath neither of the first 

 two manifest qualities, it is to be held suspected as 

 a kind of poison; for that it worketh either by cor- 



