NATURAL SCIENCES OF PHILADELPHIA. 381 



These experiments show, that, if an animal is poisoned by conia 

 after the spinal cord has been cut, galvanic irritation applied to the 

 nerves whose communication with the brain is destroyed, like gal- 

 vanic irritation applied to the nerves still in communication with 

 the brain, fails to excite contractions in the tributary muscles. 

 They also show that the moment that paralysis occurs in those 

 extremities still in communication with the brain, reflex move- 

 ments cease in the extremities whose communication with the brain 

 has been destroyed. 



Having thus proved that the paralysis is not cerebral, there still 

 remain two possible causes : first, paralysis of the spinal cord ; 

 second, paralysis of the peripheral ends of the motor nerves. To 

 determine which of these was the cause, I made a long series of 

 experiments, a number of which will now be recorded. 



Exp. 29. The left femoral artery of a cat was tied, and three 

 drops of conia were injected into the peritoneum. In three minutes 

 paresis occurred in the right posterior extremity, and in four min- 

 utes paresis occurred in both anterior extremities, while the left 

 posterior extremity moved freely. The cat continued in this 

 state for about an hour, when it commenced to recover. 



Exp. 30. Into the femoral vein of the same cat six drops of 

 conia were injected twenty-four hours after the above experiment. 

 In ten seconds, complete paralysis except in the ligatured leg, 

 where movements continue though they are slightly impaired. 



Exp. 31. Tied the left femoral artery of a very lai'ge cat. 3.03, 

 injected four drops of conia into the femoral vein. 3.03^, paraly- 

 sis of all the limbs except the ligatured one, where movements 

 continue though they are slightly impaired. 3.04, galvanization 

 of the right sciatic nerve causes no contractions, but galvanization 

 of the left sciatic causes contractions in its tributary muscles. 



Exps. 32, 33, 34, and 35. Repeated the last experiment on four 

 cats, with similar results. 



Results similar to these were obtained when frogs were experi- 

 mented with, as will be shown by the following experiment. 



Exp. 36. Tied the abdominal aorta of a medium-sized frog. 

 4.13, injected one-fourth drop of conia into the anterior portion ot 

 the body. 4.17^, paralysis is complete anteriorly, but voluntary 

 and reflex movements persist posteriorly. 4.20, the sciatics re- 

 spond to a weak current, but the median nerves will not respond 

 to the strongest current. 



