228 ELECTRIC CURRENT. I.ECT. XII. XIII. 



serve, that the most violent contractions are those which 

 are excited during the first moments of the passage of the 

 direct current. Marianini observed, that if a man close the 

 circuit of a pile composed of a certain number of elements, 

 by touching one pole with one hand, and the opposite pole 

 with the other hand, the strongest shock is always felt in 

 that arm in which the direct current circulates. 



If we continue to experiment upon the same animal, all 

 these phenomena more or less rapidly cease, according to 

 the greater or less energy of the current, and the animal 

 gives no further evidence of the passage of it. If the ani- 

 mal be then left undisturbed for some time, or, if we aug- 

 ment the force of the battery, the previous phenomena re- 

 appear. 



But it is important to follow carefully the phenomena 

 which takes place in proportion as the action of the current 

 upon the animal is prolonged, and before they completely 

 cease. You will observe that, when the direct current is 

 interrupted, the contractions of the inferior muscles (those 

 which are placed below that part of the nerve to which 

 it is applied) become more feeble, whereas they continue in 

 the muscles of the back, and the agitation, and often the 

 cries, of the animal continue. We see, also, that for the 

 first few moments of the passage of the current, its effects 

 are limited to contractions of the inferior muscles. When 

 the current is reversed, the contractions of the muscles of 

 the back, the movements of the ears, and the cries, are riot 

 manifested except at the moment of closing the circuit ; 

 while the contractions of the inferior muscles are scarcely 

 perceptible. But the opposite effect takes place when we 

 interrupt the circuit ; that is to say, the contractions of these 

 latter muscles continue, whilst those of the back, and the 

 movements of the ears disappear, and the animal ceases to 

 utter cries. 



