LETTERS TO BROTHER JOHN. 129 



air exerts on the blood in the lungs, is not merely 

 to revivify old blood, but likewise to convert the 

 chyle into blood. This conversion of chyle into 

 blood is called " sanguification." 



There is another important office fulfilled by 

 respiration ; viz. the expulsion from the body of 

 such portions of the lymph as are no longer fit to 

 remain in it, in the shape of that watery vapour 

 which we denominate " breath." The mouth, there- 

 fore, is a portal, through which you receive the 

 materials for a new body, and also through which 

 you blow away the worn-out materials of the old. 

 Every time you breathe, you blow away a little 

 bit of your nose (would it were a larger piece!), 

 a little bit of your ears, a fragment of your eyes, a 

 particle of your brain, an atom of your heart ; in 

 short, a part of your whole person. If you chance 

 to be walking in the fields, a portion, mounting 

 through the air, assists in forming the clouds ; and 

 again, descending in showers of rain, contributes 

 its share towards the formation of the multitudinous 

 ocean. Another portion falls upon the green her- 

 bage of the meadow, and constitutes a part of the 

 nourishment upon which that herbage subsists. 

 Thus, not only " All flesh is grass," but grass, 



also, is flesh. 



G 3 



