364 NATURAL THEOLOGY. 



we be directed in a course of observation likely to 

 advance the science of Life. 



The chemist is in the habit of observing the lawrs 

 of invisible powders, of elective attraction, of heat, 

 and of electrical, or galvanic, or magnetic influen- 

 ces. He makes a step, from the observation of 

 the mere ponderable and visible qualities of mat- 

 ter, to the study of laws which govern that which 

 can neither be weighed nor confined ; and we 

 should imagine, therefore, that the process of his 

 reasoning would prepare him for comprehending 

 more easily the influence of hfe, as exhibited in 

 the phenomena of the animal body. But it has 

 been far otherwise. The chemist, when he com- 

 mences the study of physiology, instead of pausing 

 and considering that he is about to enter on a new 

 region, where phenomena unexampled before are 

 to be presented to him, or are to be seen through 

 diflferent media, and the forces estimated by dif- 

 ferent means, carries along with him habits of 

 thinking which promise no improvement in this 

 new field ; and, coming encumbered with all his 

 apparatus, proceeds to measure that property 

 which gives sensibility, motion, and thought, by 

 the instruments he has hitherto employed in 

 marking the current and force of electricity ; and 

 regards the brain as no more than an electric 

 pile discharging at intervals along the nerves the 

 fluid successively developed. Such are the false 

 analogies which satisfy ingenious minds, so that 

 they cease from inquiry, and leave science sta- 



