76 ON THE NATURE AND ACTION OF THE 



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 circula- 

 tion 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 was 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 experiment 

 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 to the cause of death when a 

 considerable quantity of poison enters the arterial system at 

 once. In warm-blooded animals, as is shown by Experiment 

 LXYIII, the heart is arrested in many instances, and death 

 thus occasioned ; but when this is not the case, the appearance 

 of paralysis is probably due to affection of the nerve-centres. 



Experiment L. 



September 13th. — A ligature was placed round the middle of 

 a frog, excluding the lumbar nerves. 



3 P.M. Some dried cobra-poison dissolved in water was injected 

 into the dorsal lymph-sac. Immediately after the injection the 

 animal could move all its limbs quite well. 



3.3. Eestless ; moves all its limbs. 



3.17. Can still move vigorously. 



3.21. Can kick vigorously with its legs, especially the right. 

 When it moves it seems to overreach itself and turns over, 

 apparently from the hind limbs remaining unaffected and the 

 arms becoming partially paralysed. 



3.40. Still moves voluntarily. 



3.52. No reflex motion can be produced by touching any of 

 the extremities with acetic acid. 



