174 EXPLANATIONS. 



" If mental action is electric, the proverbial quick- 

 ness of thought, that is, the quickness of the transmis- 

 sion of sensation and will — may be presumed to have 

 been brought to an exact measurement," &c. I 

 leave the reader to judge if language more direct 

 and less illusive than this could have been 

 employed. With regard to the idea conveyed, the 

 critic has perhaps forgot, or never known, that the 

 merit of suggesting the identity of the electricity- 

 driven clockwork of Deluc with that operation of 

 the brain which produces the pulsations of the 

 heart, is claimed by his " model of philosophic 

 caution," Sir John Herschel.* The expression 

 used by that philosopher on the occasion, " If the 

 brain be an electric pile," &c., ought, doubtless, to 

 condemn him in the eyes of our critic as a man 

 enamoured of resemblances, and a user of unbe- 

 coming phraseology — if our critic be a man of im- 

 partiality. But he must (if critics be capable of 

 such weakness) revise his opinion on the subject 

 of resemblances. It might surprise even his self- 

 confident mind to find in what decisive terms 

 their utility as one of the means of advancing in 

 scientific observation is insisted on by this very 

 " model of philosophic caution." He will find the 

 passage at page 94 of the celebrated Discourse. 

 * Discourse on Natural Philosophy, p. 343. 



