130 



EXPERIMENTAL PHARMACOLOGY 



ether valve are not used in this experiment. The opening 

 up into the cap should be closed with a cork.) Any ordi- 

 nary ether bottle with a side pass as shown in Fig. 107 may 

 be used for this purpose instead of the valve here shown. 

 Just to the left of the ether bottle is a smaller bottle con- 

 taining mercury. The cork in this bottle is perforated by 



-Flexible 

 Breathing 

 Bay 



Metallic muzzle 

 with rubber cushion 



Fig. 123. Schematic arrangement of an apparatus for administering nitrous oxide 

 (ether, etc.) to an animal. The gas or vapor (ether; is washed (by means of the air 

 pump) through NaOH solution (to remove CO 2 ) and through HoSO* (to remove watery 

 vapor). Oxygen is admitted as needed by the animal. The animal breathes into and 

 out of the ventilated bag. 



two holes through one of which a tube from the main air 

 way dips down just below the surface of the mercury. 

 This tube can be raised or lowered and thus serves as an 

 adjustable pop-off valve to regulate the pressure if it be- 

 comes too great. To the left of the mercury bottle a mer- 

 cury manometer and scale are placed. The manometer 



