LECT. XIV. XV. is ELECTRICITY EVOLVED? 271 



of elements all alike, and formed of an entire thigh, of a 

 portion of spinal marrow, and of a half- thigh. You can 

 easily understand how I compose a muscular pile with these 

 elements, by applying the external part of the entire thigh 

 to the internal part of the divided thigh of the following 

 element. Afterwards I plunge the two extremities of the 

 galvanometer into the liquid, in which the two extremities 

 of the pile terminate. By means of a slight modification in 

 the two extremities of the galvanometer, I have no occasion 

 to hold them with the hands in order to keep the circuit 

 closed. 



I have repeated this experiment many times, by employ- 

 ing piles of a dozen, sixteen, or twenty elements. The first 

 deviation, as well as the permanent one, is sometimes 

 weaker than that obtained with piles composed of a like 

 number of half-thighs. This difference must be ascribed 

 principally to the greater length and resistance offered by 

 the circuit. In all these cases, after having allowed the 

 needle to become stationary, indicating a deviation- which, 

 in my different experiments, varied from 10 to 12 or 15, 

 I rapidly touch the lumbar plexus of the elements of the 

 pile with a concentrated solution of potash ; excepting, 

 however, the two last, lest the solution should reach the 

 liquid in which the extremities of the galvanometer are 

 plunged. The muscular contractions became manifest after 

 the application of the alkali, and continued for some instants, 

 without scarcely ever being sufficiently strong to destroy 

 the contact, by separating the elements from each other. 

 During these contractions, if the experiment be made without 

 any interruption or change in the circuit, the needle of the 

 galvanometer undergoes no variation. 



In some cases, however, I have seen the needle descend, 

 in others augment, 2 or 3, but these variations are un- 

 certain; they are wanting in tke greater namber of cases, 



