ETHYL CHLORIDE,, CHLOROFORM, ETHYL BROMIDE 



61 



(b) Blow out the ether vapor with pure air and repeat 

 the stimulations. Does the nerve return to normal? 



(c) With a Gebauer or Kelene tube (Fig. 54) spray a 

 little ethyl chloride through the gas chamber. Do not 

 freeze the nerve. Quickly repeat the stimulations and note 

 the effects on the nerve. What do you observe? 



(d) Blow out the ethyl chloride from the gas chamber 

 and obtain new "normal" contractions of the muscle. If 



Fig. 55. Method of smoking drums (in a hood). Benzol is placed in the one pint 



milk bottle. 



the nerve is dead a new preparation should be made. Place 

 a few drops of chloroform in the ether bottle and blow the 

 vapor of this through the gas chamber. Again stimulate 

 the nerve with the needle and with the boot electrodes. 

 What do you observe? What can you say as to the relative 

 action of ether, ethyl chloride, and chloroform on isolated 

 nerve trunks? Ethyl bromide may also be tried similarly. 

 Before taking down the apparatus stimulate the muscle 

 itself directly a few times to determine its condition. This 

 is easily done if a very fine copper wire instead of a thread 



