50 ON THE NATURE AND ACTION OF THE 



vened in half an hour after the injection of the poison, while 

 the muscles of another animal killed at the same time by 

 decapitation retained their irritability for many hours. 



Experiment XXVII. 



May 8th, 1873. — Eight thigh of a frog ligatured, with the 

 exception of the sciatic nerve. Animal poisoned by the intro- 

 duction of some dried cobra-poison dissolved in water into the 

 lymph-sac of the back. After the animal had become com- 

 pletely paralysed, the gastrocnemii of the two legs were 

 irritated by an induced current (1 bichromate cell). 



Left leg (poisoned), distance of coil 13'5, contraction ; right, 

 24*0, contraction. 



Experiment XXVII (a). 



Another frog prepared in the same way gave at first : — left leg 

 (poisoned), distance of coil 42*2, contraction ; right (ligatured), 

 distance 21*0, contraction. 



After some time : — left leg, distance 6*0, contraction ; right, 

 distance 25-0, contraction. 



Some time later : — left leg, distance 0, almost no contraction ; 

 right leg, distance 14'5, contraction. 



In this experiment, the poisoned muscle at first responded 

 more readily to the irritation than the one which had been 

 deprived of blood by the application of a ligature ; and this 

 renders more apparent the effect of the poison, in causing rapid 

 diminution and final extinction of irritability in the muscle to 

 which it had access, since the other lost its excitability very 

 slowly. 



Experiment XXVIII. 



September 5th. — About 2.35 p.m. injected f c.c. of a 2-per- 

 cent, solution of dried cobra-poison into the thoracic cavity of 

 a guinea-pig. It was uncertain whether the lung (right one) 

 was pierced by the point of the needle or not. Within a few 

 seconds the animal gave several convulsive struggles, and died 

 in half a minute or so. The head was then cut off. Immedi- 

 ately afterwards a second guinea-pig was killed by decapitation. 



