352 



galvanic current on one set of lumbar nerves ; and, certainly, with 

 the key furnished by Dr. Rousseau, reflex nervous action is not 

 required to explain the phenomenon. 



The following diagram will give the case in which the lumbar 

 nerves on one side are acted upon by the inverse primitive current, 

 a a being the lumbar nerves, P N the poles of the galvanic appa- 

 ratus, the black arrow the primitive current, the dotted arrows the 

 derived current. The results, as seen in contraction in the limb 

 belonging to the same side, or in that belonging to the opposite side, 

 are seen in the Table below the figure. The case is plain. 



Fig. 1. 



On the side acted upon by the inverse primitive current, the por- 

 tion of nerve nearest to the muscles supplied by the nerve (the 

 muscles of the leg) is traversed, not by the inverse primitive cur- 

 rent, but by a direct derived current ; and hence we should expect 

 to find in the leg on this side (for at the time of these alternate 

 contractions the nerve is in the state in which the current produces 

 contraction alternately at the beginning of the direct current and at 

 the end of the inverse current) the effects of a direct current con- 

 traction at the beginning of the current. We should expect to find 

 this ; for of two currents acting upon the same nerve, it is the one 

 nearest to the muscles supplied by the nerve which acts upon these 

 muscles. In the limb on the opposite side we should expect, on the 

 contrary, the effects of an inverse current contraction at the end of 



