1874.] Poison of Indian Venomous Snakes. 107 



in this instance became paralyzed before the motor nerves. It is indeed 

 difficult to say whether the motor nerves were paralyzed in this case or 

 not, as the muscles themselves were distinctly weakened. 



Experiment XLIX. 



Dec. 1st, 1872. The right leg of a frog was ligatured, excluding the 

 sciatic nerve, which was kept covered by a flap of skin to prevent its 

 becoming dry. A ligature was also put round the left leg in a similar 

 manner, but not tightened. 



2 P.M. Cobra-poison injected into the abdominal vein. 



The effect not being marked, the aorta was exposed. 



2.27. Some poison injected into the aorta. It seemed to take effect 

 at once ; all motion ceased immediately. 



2.30. The ligature was then tightened round the left leg. 



2.48. The frog has since moved ; but all motion has now ceased. 



2.52. Even when irritated by acetic acid there is no movement. The 

 heart is still contracting. 



No reflex action occurs when a strong interrupted current is applied 

 to the nose or limbs. 



Lumbar nerves exposed and irritated. 



Bight. Distinct contraction of thigh. Coil at 58*5. 



Left. Do. do. 



Eight. Distinct contraction of whole leg. Coil 50. 



Left. Do. do. 



Sciatics exposed and irritated. 



Eight. Contraction. Coil 77'0. 



Left. ' Do. 52*0. 



3.28. Eight. Do. 50. 

 Left. Do. 43. 



The poisoned leg seems to be losing its irritability more quickly than 

 the other. Irritability of spinal cord gone. 



3.35. The left still contracts, with the coil at 35. The other, when 

 irritated by a current of the same strength, contracts more strongly. 



The loss of power occasioned by the cessation of the circulation in the 

 ligatured limb (which is used as a standard with which to compare the 

 other) was diminished in this experiment, by injecting the poison directly 

 into the circulation, so as to enable it to reach the motor nerve-ends at 

 once. As soon as it had taken effect, the poisoned leg \vas likewise 

 deprived of its circulation, so as to bring the two limbs as nearly as 

 possible into the same conditions. The cause of death, in this experi- 

 ment, was paralysis of the cord, all reflex action having been almost 

 immediately abolished by the large dose of the poison injected into 

 the circulation, though the heart continued to beat. The motor nerves 

 were not at first affected ; but after a little while paralysis appeared in 

 the poisoned limb. This experiment is especially interesting in reference 



