ELECTRICITY AND LIFE. 167 



sation called out by the first is almost insignificant, the 

 others, besides the permanent muscular contraction, pro- 

 duce a pain lasting as long as the nerve retains its excita- 

 bility. The spinal marrow is one of the most active parts 

 of the system. In the form of a thick, whitish cord, lodged 

 inside the vertebral column, it constitutes a real prolonga- 

 tion of the brain, of which, under some circumstances, it 

 takes the place. The unconscious depository of a part of 

 the force animating the limbs, by means of the nerves sent 

 out from it, it transmits to them their direction and power 

 to move, while the brain is unaware of its action. This 

 takes place in what are called reflex motions, and these 

 occur in beheaded animals, through the simple excitement, 

 direct or indirect, of the spinal marrow. Experiments may 

 be cited, showing the action of electricity on those phe- 

 nomena which have their seat in the spinal marrow. If a 

 frog is plunged into lukewarm water, at a temperature of 

 40, it loses respiration, feeling, and motion, and would die 

 if kept in it a long time. When taken out of the water, 

 and placed in this state under the action of the current, it 

 contracts strongly when its vertebral column is electrified 

 by an ascending charge ; but no motion follows if the de- 

 scending current is applied. On the other hand, if the 

 latter is sent into a beheaded animal, stimulated to reflex 

 motions, by the excitement of the spine, it tends, as ex- 

 periment shows, to paralyze these motions. In general, 

 this is the law discovered by Onimus and Legros the as- 

 cending battery-current, directed on the spine, increases the 

 excitability of that organ, and consequently its power of 

 producing reflex phenomena ; the descending current, on 

 the contrary, acts in the reverse way. 



When the brain of animals is directly electrified, the 

 modifications in circulation already spoken of result, but 

 no special phenomena are observed. The animal shows no 

 pain, and makes no movement, experiencing a tendency 



