106 POLARIZED OOKDITION OF THE CHAP. IX, 



be too strongly insisted upon. It is by nutritiob. 

 that the force is maintained, and it is by this act 

 that it is renewed. If the changes in each tissue 

 are not properly carried on, or should fail in one or 

 both of them, spasms or convulsions may be induced 

 at one time, or the contrary effect, such as paralysis, 

 might occur at another. 



It may be urged as an argument against the 

 views now taken, of muscular force and nerve force 

 being •polar, that they are considered as identical. 

 So far as they are polae they are identical ; but the 

 conditions under which the force exists in the two 

 tissues diflfer. In the muscle it is limited to, and 

 associated with, that tissue, and may be considered 

 as existing in a italic form. In the nerve it may 

 also exist in this form, the static, but it is capable 

 also of being transmitted from one point to the other, 

 in consequence of the peculiar organization of the 

 nervous tissue. The identity between the two forces 

 removes those difficulties that might otherwise arise 

 in considering their reaction one upon the other. 

 Muscular force and nerve force must not be supposed 

 to be produced by their respective tissues, but asso- 

 ciated with them ; the modes under which they *Fe 

 manifested differ, and would indicate that the form 

 under which nerve force exists would prove it to be of 

 a higher character than that o{ muscular force K 



' Fide Faradatt's Paper on the Gymnotus, (Ezpeiimental 

 Eesearohes, vol. ii. p. 16.) on the " Relation bettreen Nervous 

 Power and Electricity." 



