358 PHYSIOLOGICAL ACTION OF CONDURANGO. 



has been recommended especially in cases where a drug possess- 

 ing an influence over tissue change would be likely to be 

 serviceable. The experiments of Boeck have, however, shown 

 that those drugs, such as iodine, morphine, and quinine, which 

 have some effect upon tissue change, produce but very slight 

 alterations compared with those which result from variations in 

 food, and Toldt and Nowak have found that the amount of 

 nitrogen varies even in the flesh of the same animal, so that it 

 would be almost necessary to analyse the flesh eaten every day 

 a,s well as rigorously to fix its amount, and this would be more 

 than anyone could well undertake who could not devote his 

 whole time to the work. 



General Summary. 



Watery extract of Condurango has no action on frogs even 

 when injected into the dorsal lymph-sac in doses of 5 grains. 

 On rabbits it has no poisonous action when injected into the 

 peritoneal cavity. When a solution containing fine particles in 

 suspension is injected into the jugular vein the animal dies with 

 symptoms of opisthotonos. When the coarser particles are 

 removed this does not occur although the breathing is quickened. 

 It is not improbable that the quickening of the breathing is 

 due to the lodgments of fine particles in the pulmonary capil- 

 laries, and that the opisthotonos which I noticed in one experi- 

 ment (Exp. IX) and which has been supposed by Gianuzzi and 

 Bufalini to be due to the direct action of Condurango on the 

 nerve centres was really due to asphyxia caused by pulmonary 

 embolism. 



Unlike quinine Condurango has very little effect on reflex 

 action.* 



Condurango when injected into the peritoneum even in large 

 doses has no action on the blood-pressure. 



It does not exert any definite action on the arterioles nor 

 does it paralyse the peripheral terminations of the vagus. 



* Since the preceding experiments were made Mr. Pardington and I have 

 found that the diminution in reflex excitability which Chaperon described as 

 caused by the injection of quinine into the lymph- sac of the frog probably 

 depends on the local irritation produced by the acid in which the quinine is 

 dissolved. 



