OF VITAL MOTION. 91 



time when the slight contractions take place in the 

 limbs. These contractions, however, are accompanied 

 with signs of pain and suffering, and Matteucci has 

 shown that they are due to the reactions of the nervous 

 centres, and not to the direct agency of electricity, 

 for they cease when the nervous communication with 

 the spinal cord is destroyed. 



In all these experiments, where free electricity is 

 used, it is immaterial whether it be procured from a 

 metallic battery or from the muscular pile. In each 

 case the effects are the same, and the contraction 

 would seem to be coincident with the removal or 

 neutralization of the agent. 



There is some reason also for supposing that the 

 operation of galvanism and of nervous influence har- 

 monizes more closely than would appear at first sight. 

 It seems, indeed, as if the galvanism gave rise to 

 instant contraction when passed in the same direction 

 as the motive nervous influence ; but it must be re- 

 membered that we have found some reason to believe 

 that the nervous influence is abstracted during con- 

 traction and not communicated, and hence it may be 

 necessary to change our ideas in relation to the transit 

 of nervous fluid in the motor nerves, the current being 

 to and not from the brain, that is to say, in the same 

 direction as the natural electrical current. Be this as 

 it may, however, it is not with nervous influence that 

 we are concerned when speaking of the effects of elec- 



