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 1t 1s 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 nghly 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 poimt,—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, 1s transformed into electricity; and, in the 
case of phosphorus and many other bodies, a 
portion of this electricity into hght. This latter 
