NITRITES AND STIIYCIIXIN'E. 391 



was then removed from the legs of Loth and the muscles 

 irritated by the application of the current directly to them. 

 In many instances, those of the frog poisoned by the nitrite and 

 the strychnia together contracted nearly as strongly and readily 

 as those poisoned by the nitrite alone. It is therefore evident 

 that their failure to contract when the nerves were stimulated 

 must have been due to paralysis of the nerves themselves, just 

 as it is in poisoning by woorara. The second series of experi- 

 ments was made by ligaturing the artery supplying one leg of 

 a frog before injectiug strychnia into the lymph sac. The 

 poison was thus carried by the blood to every part of the 

 body except the leg whose artery had been tied. The animal 

 was then placed in a vessel filled with the vapour of nitrite 

 of amyl as before, and after motion had ceased the sciatic 

 nerves were exposed and irritated. It was then found that 

 the muscles of the ligatured leg which had been exposed to 

 the nitrite of am.yl, but preserved from the strychnia, con- 

 tracted vigorously when the corresponding sciatic was irritated, 

 while those of the other leg did not respond at alL When the 

 skin was stripped olT, however, and the muscles irritated directly, 

 in many instances no great difference could be noted between 

 their irritability. 



The muscles of frogs which had been poisoned either with 

 strychnia and nitrite of amyl, or with nitrite of amyl alone, 

 passed more quickly than nsual into a state of rigor mortis ; 

 and I therefore regard nitrite of amyl as a muscular poison. 

 It is not improbable that the apparent paralysis of the motor 

 nerves may be partly due to diminution of the irritability of 

 the muscle itself, but the results of direct stimulation show 

 that this is not sufficient to explain it entirely, and we must 

 therefore believe that the nerves themselves are also paralysed. 

 Besides nitrite of amyl, I have tried the nitrites of sodium, 

 ethyl, butyl and capryl; but my researches on these are not 

 yet completed. They seem, however, to show that the nitrites 

 are muscular poisons, but their actions differ according to the 

 bases which they contain. 



