3S CDKBENT FORCE CHAP. IV. §. I. 



thus found that a deeper insight into a knowledge of 

 Faraday's opinions in respect both to the origin of 

 the power in the voltaic circle, and to that of current 

 jorce in particular, viz. as an axis of power having 



CONTRARY FORCES EXACTLY EQUAL IN AMOUNT IN CON- 

 TRARY DIRECTIONS, was absolutely essential. I have 

 endeavoured in chap. ii. to give a brief account of 

 his views on this point; and I may also refer to 

 Whewell's Philosophy of the Inductive Sciences, 

 vol. i. p. 331. first edition, to the chapter ' On the 

 Scientific Application of the Idea of Polarity.' 



Dismissing the notion that the stomach and liver 

 are related to each other in the same manner as the 

 'poUs of a galvanic circle are mutually dependent, and 

 with a more correct knowledge of the origin of the 

 power in the galvanic circle derived from Faraday's 

 memoirs, the thought arose that it might be during 

 the formation of the secretions where the changes 

 were actually going on, that the evidence sought 

 for could possibly be obtained. How far these 

 surmises were correct wiU now be seen. 



Sect. I. On the Manifestation of Current Force during 

 the formation of the Secretions in the miicous mem- 

 hrance of the alimentary canal, viz. the stomach and 

 intestines. 



The mode of employing the galvanometer and of 

 conducting the experiinents, together with the pre- 

 cautions necessary to be observed, have been alluded 

 to in chap. iii. 



