ON THE APPARENT PE,ODUCTION OF A 

 NEW EFFECT BY THE JOINT ACTION OF 

 DEUGS WITHIN THE ANIMAL ORGANISM. 



(From the Journal of Anatomy and Physiology, November, 1873, yol. viii, 



T). 91.) 



The admirable researches of Crum Brown and Eraser have 

 demonstrated that the physiological action of several alkaloids 

 may be completly altered by tlieir union with such bodies as 

 iodide of methyl. The compounds thus produced sometimes 

 act on organs which do not appear to be affected by either of 

 the components separately, the ends of the motor nerves for 

 example being paralysed by iodide-of -methyl-strychnia, though 

 neither iodide of methyl alone, nor strychnia alone, seems to 

 have much influence over them. Although chemical action 

 outside the body alters in this way the action of alkaloids, I 

 am not aware that any instance has been noticed in which a 

 similar modification appears to be produced by the joint action 

 of two drugs after their introduction into the animal organism. 

 I have lately observed an example of this sort in the case ot 

 strychnia and nitrite of amyl. The experiments which I made 

 on this subject were performed in several ways, but I will only 

 describe the two most important. In the first series of experi- 

 ments a solution of strychnia was injected into the dorsal 

 lymph sac of a frog, and as soon as tetanus came on the 

 animal was put into a vessel filled with the vapour of nitrite 

 of amyL A second healthy frog was also introduced along 

 with it for the purpose of comparison. They were left in the 

 vessel till both were motionless, when they were removed and 

 the sciatic nerves of both were exposed. On irritating these 

 nerves by the application of a Faradic current, vigorous con- 

 tractions occurred in the limbs of the frog poisoned by nitrite 

 of amyl alone, but those of the animal poisoned by strychnia 

 and nitrite of amyl together remained motionless. The skin 



