LETTER IV. 



SIR, 



I MUST acknowledge, that your third Lec- 

 ture abounds with many solid and striking ob- 

 servations on the extent and limits of human 

 science as connected with physiology : in which, 

 as you remark,* " we follow the links of an 

 ** endless chain, and by holding fast to it, we 

 " may ascend from one link to another; but 

 " the point of suspension is not within the 

 " reach of our feeble powers." 



<c To call life," you continue, " a property 

 " of organization would be unmeaning it 

 " would be nonsense." Now, Sir, permit me 

 to confront this opinion with the following sen- 

 tence in the ensuing Lecture. f " Such a kind of 

 " composition (viz. of solids and fluids) and such 

 " an arrangement of the constituent parts, is 

 " called organization ; and as the vital pheno- 

 " mena are only such motions as are consistent 

 " with these material arrangements, life, so far 

 " as our experience goes, is necessarily con- 

 " nected with organization. Life pre-supposes 

 " organization, as the movement of a watch 

 " pre-supposes wheels, levers, and other mecha~ 

 " nism of the instrument." 



* P. 82. f P. 93, and p. 104 



