118 



EXPERIMENTAL PHARMACOLOGY 



some oxygen into the bottle. What effect does this have on 

 the animals? It is to be noted that this experiment permits 

 comparison of the relative effects of the substances ad- 

 ministered on warm-blooded and cold-blooded animals. The 



Outlet 

 Gebauer's eihyl chlorid 



Fig. 115. Method for studying the action of nitrous oxide, ethyl chloride, carbon 

 dioxide, oxygen, increased (or decreased) atmospheric pressure on warm and cold-blooded 

 animals. 



skin absorption or excretion of the frog should be held in 

 mind. Increase the amount of oxygen in the bottle. Then 

 with the greatest caution raise the oxygen pressure in the 

 bottle by closing the outlet and opening the clip on the tube 



