84 POLABIZED CONDITION OF THE CHAP. Vin. 



regard to the origin of the muscular or of the nerve 

 current in the experiments we have been lately con- 

 sidering, viz. when the two surfaces of a muscle or 

 of a nerve, the transverse section and the external 

 surface, are formed into a circuit. During nutrition, 

 the tissue is deposited as an anion, the cation passing 

 on in the blood; the negative electric condition of 

 the tissue is maintained by nutrition, and continues 

 in that state; it may, perhaps, be looked upon as 

 being in a state of tension, polarized ; and when the 

 muscular or nerve fibre, and any other part — for 

 instance, the sarcolemma or the neurilemma — are 

 formed into a circuit, an effect is produced upon the 

 needle, indicating the existence of a current. Under 

 these conditions, the results become analogous or 

 are identical with those that are observed with a 

 charged Leyden jar, when the inner and outer 

 surfaces are formed into a circuit; the tissue being 

 negatively electrized may, perhaps, render the sarcO; 

 lemma or neurilemma positive by induction^ 



In speaking, therefore, of the fibre as being in 

 a polarized condition, it would lead to erroneous 

 views if we supposed that one portion, taking its 

 longest diameter, was positive or negative to the other, 



^ This positive condition of the external surface will go far 

 to explain a circumstance which at one time rather perplexed 

 me. When the external surface of a muscle, and the venous 

 blood flowing from it, were formed into a circuit, the effect upon 

 the needle was but slight ; the external surface of the muscle 

 and the blood being both positive, will full; account for the 

 feebleness of the current then manifested. 



