INFLUENCE ON SECRETION. 23 



Nysten, Humboldt, and other eminent physiologists ; and it is 

 therefore needless here to dwell on the matter. 



Another curious fact connected with this interesting suhject is, 

 that to produce the convulsions of a muscle by this agent it is not 

 necessary that the electric current should extend to it, or that it 

 should be included in the circuit. It is quite sufficient that the 

 circuit should be completed through the smallest portion of the 

 nervous trunk which supplies the muscle. This fact is amply 

 proved by the experiments made by Nobili. 



From all the facts 'then that have been collected on the subject 

 of muscular contraction caused by the application of Voltaic 

 Electricity, the following conclusions may be deduced : 



1. The muscular fibre is sensible to the stimulus of Galva- 

 nism when applied directly to it. 



2. When an electric current is suddenly transmitted through 

 a nerve to a muscle, or in the inverse direction, the muscle is 

 thrown into spasmodic action. 



3. The same effect is produced upon suddenly interrupting the 

 electric current, when moving in either of the directions just 

 described. 



4. Precisely similar results are obtained upon completing the 

 circuit through a portion of the nervous trunk which is distributed 

 to a muscle, and upon interrupting it after being completed. 



5. The most powerful contractions are produced by trans- 

 mitting the direct current. 



6. The next in point of energy are those which occur upon 

 interrupting the inverse current. 



INFLUENCE OVER THE SECRETORY ORGANS. It was our cele- 

 brated countryman, Dr. Wollaston,* who published the earliest 

 conjectures in reference to the influence of Galvanism upon the 

 secreting organs. Reflecting upon the wonderful powers of 

 decomposition and transfer which Davy had lately shewn that 

 the pile was capable of exerting, and upon the fact of a distinct 

 electric apparatus having been detected in certain fishes, it 



Philosophical Magazine, vol. xxxiii. p. 488. 



