284 LETTERS TO BROTHER JOHN. 



not ; the eye sees not ; the olfactory nerves take no 

 cognisance of odours. 



SLEEP. 



Solidification that is, the conversion of blood 

 into the solid parts of the body goes on only 

 during sleep. The chief end, indeed, and object 

 and intention of sleep, would seem to be this final 

 assimilation of our food this solidification of the 

 blood into the several solid parts of the body. 



The accomplishment of this miraculous change 

 seems to have required the perfect concentration 

 of all the energies of the system upon itself. It 

 seems to have required, that the attention (if I may 

 so speak) of the brain and nervous system should 

 not be distracted by any other object. It seems to 

 have required, that every thing, both within and 

 without the body, should be hushed into profound 

 repose during the accomplishment of this nightly 

 wonder, in order that nothing might disturb or 

 interfere with the exquisite and miraculous pro- 

 cesses employed to effect it. To this end, the por- 

 tals of sensation are closed the eye sees not the 

 ear hears not the skin feels not the very breath- 

 ing is scarcely audible the pulsations of the heart 

 scarcely perceptible: all the living energies are 



