118 DAUGEEOUS EFFECTS OF TILE SHOCK. 
the animal’s body. The same vessels which penetrate be- 
tween the plates or leaves of these organs, and which cover 
them with blood when they are cut transversely, also send 
out numerous branches to the exterior surface of the air- 
bladder. I found in a hundred parts of the air of the swim- 
ming-bladder four of oxygen and ninety-six of nitrogen. 
The medullary substance of the brain displays but a feeble 
analogy with the albuninous and gelatinous matter of the 
electric organs. But these two substances have in common 
the great quantity of arterial blood which they receive, and 
w hich is deoxidated in them. We may again remark, on 
this occasion, that an extreme activity in the functions of 
the brain causes the blood to flow more abundantly towards 
the head, as the energy of the movement of the museles 
accelerates the deoxidation of the arterial blood. What a 
contrast between the multitude and the diameter of the 
blood-vessels of the gymnotus, and the small space occupied 
by its muscular system ! This contrast reminds the observer, 
that three functions of animal life, which appear in other re- 
spects sufficiently distinct, — the functions of the brain, those 
of the electrical organ, and those of the muscles, all require 
the afflux and concourse of arterial or oxygenated blood. 
It would be temerity to expose ourselves to the first 
shocks of a very large and strongly irritated gymnotus. If 
by chance a stroke be received before the fish is wounded 
or wearied by long pursuit, the pain and numbness are so 
violent that it is impossible to describe the nature of the 
feeling they excite. 1 do not remember having ever received 
from the discharge of a large Leyden jar, a more dreadful 
shock than that which I experienced by imprudently placing 
both my feet on a gymnotus just taken out of the water. 
I was alfected during the rest of the day with a violent pain 
in the knees, and in almost every joint. To be aware of the 
difference that exists between the sensation produced by the 
Voltaic battery and an electric fish, the latter should be 
touched when they are in a state of extreme weakness. The 
gynmoti and the torpedos then cause a twitching of the 
muscles, which is propagated from the part that rests on the 
electric organs, as far as the elbow. We seem to feel, at 
every stroke, an internal vibration, which lasts two or three 
seconds, and is followed by a painful numbness. Accord- 
