122 



EXPERIMENTAL PHARMACOLOGY 



bottom of the large pan shown in Fig. 116 pour a layer of 

 strong (not saturated) sodium (or potassium) hydrate solu- 

 tion about three-fourths inch deep. The solution must not 

 be warm. Stretch the thin rubber bath cap air-tight over 

 the rim of the large pan as illustrated. Thereafter do not 

 iip set the pan nor splash out the solution. If the dog strug- 



Wheei wrench 



-Yoke 



Oxyqen 

 tank 



Fig. 116. Apparatus used for closed ether (ethyl chloride, chloroform, nitrous oxide, 

 etc.) anesthesia. A large, shallow, round cake pan covered by a thin bath cap holds 

 the vapors or gases. The animal breathes into and out of the pan through a spout. 

 Strong sodium (or potassium) hydrate solution (which must be cold) in the bottom of 

 the pan absorbs the CO 2 eliminated. A diagrammatic view of the pan as seen from above 

 is shown in Fig. 118. Oxygen is admitted as needed by the animal from the tank (or 

 from the apparatus shown in Figs. 176 and 177). Ether or chloroform or ethyl bromide 

 may be injected through the burette. Ethyl chloride can lie sprayed in through one of 

 the inlets. (See Journal of Laboratory and Clinical Medicine, 1916, ii, p. 94; also ibid., 

 1916, ii, p. 145.) 



gles this might occur, but such an accident is much more 

 likely to happen as the result of awkwardness. Etherize 

 the dog on the floor in the usual manner (Fig. 71). Then 

 place it quickly on the operating board, tie it down and 

 insert the tracheal cannula. The straight end of the can- 



