38 On the Effects of Certain Fhysica I and 



means of the platinum wire, movements are observed on con- 

 necting the plates a and h. The nerve d has become affected 

 with the electrogenic state, and this is discharged with mus- 

 cular phenomena, on uniting a and h, 



Ex. 17. Our next experiment is pourtrayed in fig. 7. 

 The plates of platinum connected with the " couronne de 

 tasses" are laid across the lumbar nerve at d and g, the di- 

 rect current passing through the intervening portion of nerve. 



On completing the circle, muscular movements were ob- 

 served in the right posterior extremity b. On connecting a 

 and 5, there were slight movements in b, but none in c. On 

 connecting a and c, no movements occurred either in b or c. 

 On connecting b and c, energetic movements were excited in 

 both these limbs. On connecting d and/, e and/, and </and 

 e, movements occurred in b. After these experiments, on 

 connecting d and a, there were movements in both limbs, the 

 induced nerve and the spinal marrow being a part of the cir- 

 cuit. On connecting a and b, there were movements in 6, and 

 reflex movements in c. 



If the Voltaic circle now be broken, — if the whole Voltaic 

 arrangement be removed, a series of phenomena are still ob- 

 served ; thus, — if under these circumstances we unite d and c, 

 and e and c, there are movements in the limbs b and c ; if we 

 connect d and 6, and e and 6, there are still movements in 6, 

 greater in the former case, less in the latter ; the right lum- 

 bar nerve being and remaining in the electrogenic condition, 

 and being then discharged with muscular movements. 



Ex, 18. If the experiment be arranged as in fig. 8, there 

 are movements on connecting c and a, c and 6, and c and d\ 

 but none on connecting a and 6, b and d^ and d and a. 



It will be observed, that movements take place whenever 

 the connections are so made as to admit of new or superadded 

 circles, including the zinc and silver arc, but not otherwise ; 

 that is, in the first instance ; for one such connection with its 

 attendant movements is sufficient to effect an electrogenic 

 state of the nerve, the action of which may be independent, 

 and persist after the Voltaic apparatus is removed. 



Ex. 19. This experiment is represented in fig. 9 ; the cur- 

 rent from the ** couronne de tasses" is direct in the limbs a 



