THEORY. 189 



part of the nerve. As soon as electricity meets 

 with the nerve, it finds the necessary medium for 

 transforming itself into another kind of vibration, 

 which we call nervous force, and this passes into 

 muscular motion, or contraction. Reciprocally, 

 when we hold in our hands the two wires of a 

 galvanometer, and, by a muscular contraction, 

 set the needle of the instrument in motion, we 

 cannot say it is nervous force which moves the 

 needle ; this motion is owing to electricity, result- 

 ing itself from the transformation of a certain 

 amount of nervous force. 



It is highly probable that this doctrine of trans- 

 formation may apply to nervous force and instinct 

 or will ; though we enter here into considerations 

 which are beyond our present means of experi- 

 ment. 



In nature, we can almost always connect light 

 with electricity as a starting point, especially 

 when it concerns bad conductors. When an elec- 

 tric current passes through a bad conductor, a 

 great amount of electricity is transformed into 

 light, and the body experimented on becomes 

 luminous. Again, in the combustion of phos- 

 phorus, as in every chemical action, a certain 

 amount of what we call chemical force or chemical 

 affinity, is transformed into electricity ; and, in the 

 case of phosphorus and many other bodies, a 

 portion of this electricity into light. This latter 



