LETTERS TO BROTHER JOHN. 145 



do with the quantity of nourishment which we 

 derive from it : for, as the stomach, liver, &c. can 

 only furnish, at one time, enough of their several 

 juices to convert a certain portion of what we eat 

 into chyme and chyle, it is manifest, that only a 

 certain portion can be converted into blood. And 

 as blood is the sole aliment from which we can 

 derive sustentation, it is equally manifest that we 

 cannot derive any benefit from what we eat, ex- 

 cept from that portion of it which in due course 

 becomes blood. All that we eat, therefore, beyond 

 what can be converted into blood, is either changed 

 into that useless encumbrance called fat, or is left in 

 the stomach and bowels to run into fermentation ; 

 serving no other purpose than to distend these or- 

 gans with all sorts of pernicious and offensive gases. 

 You will also see, now, how true it is, that to 

 talk about strong stomachs is, in fact, only to talk 

 strong nonsense : for you have been reading for 

 the last ten minutes to but little purpose, if you 

 have not remarked, while tracing the food from its 

 existence as food to its existence as blood, that the 

 stomach answers no other purpose than simply 

 that of a bag, whose office it is to receive the food, 

 to detain it for a given time, and then empty it 

 into the bowels. The strength which is requisite 



