346 



PHYSIOLOGICAL ACTION OF CONDURANGO. 



Experiment XL — Four frogs were suspended by their arms, 

 and their feet irritated by a very dilute sulphuric acid. After 

 each application of the acid the foot was carefully washed. 



In the following account R stands for right foot, L for left 

 foot, and the numbers under each indicate the number of 

 seconds before the foot was drawn out of the dilute sulphuric 

 acid. 



Time. 



Frog I. 



Frog II. 



Frog III. 



Frog lY. 



Eemarks. 



Frog I was tested first, 

 but on dipping its 

 right foot into the 

 acid, it became ap- 

 parent that it was 

 too strong. It was 

 therefore diluted 

 and again applied. 



Two grains of extract 

 of Condurango were 

 suspended in a few 

 drops of f per cent. 

 NaCI solution, and 

 injected under the 

 skin of the back of 

 Frog IV. 



On touching the feet 

 of Frogs II, III, and 

 IV, they drew them 

 away much more 

 readily than Frog I. 



Eeflex action again 

 tested by acid. 



Frog I was not so lively as the others, and it will be seen 

 from the next experiments that the diminution of reflex action 

 which occurred in it during this experiment is not a general 

 rule but due to an individual peculiarity. 



Experiment XII. — Two frogs were suspended by the head and 

 reflex action tested by dilute sulphuric acid (one part acid to 

 250 of water). 



