138 LETTERS TO BROTHER JOHN. 



ticle of food must, therefore, return to the upper 

 part of the stomach, to be again submitted to the 

 agency of the gastric juice, before it can be permitted 

 to escape from the stomach into the bowels. Is not 

 this a beautiful exemplification of the importance of 

 the sensibility of our organs ? and said I not truly, 

 when I called it " our guardian angel"? For what 

 is the sensibility of the pyloric valve, by which it is 

 enabled to distinguish between perfect and imper- 

 fect chyme ? what is it, I say, but a watchman, a 

 sentinel, posted at the entrance into the bowels, in 

 order to watch over their safety; to see that no- 

 thing be allowed to enter which is likely to disturb 

 or irritate them; to take care that nothing inju- 

 rious, nothing offensive, nothing which may be in 

 any way hostile to their safety, nothing, in fact, 

 which has no business there, be permitted to tres- 

 pass within the sacred precincts of organs so impor- 

 tant to the health and welfare of the whole being, 

 of which they form so vital a part ? 



That imperfectly chymified food cannot enter 

 the bowels without injury to them is sufficiently 

 proved by the very existence of this valve. For 

 surely it is foolish to suppose that nature, who 

 does nothing in vain, would have been at the 

 pains' of establishing so beautiful, so wonderful 



