﻿BOTANICAL GAZETTE 



10 minutes the resistance rose to 850 ohms; during the next 

 10 minutes it fell to 800 ohms; it continued to fall rapidly during 

 the next 40 minutes, reaching 680 ohms at the end of this period. 

 The tissue was then placed in sea water; in the next 10 minutes 

 the resistance fell to 660 ohms. This fall in resistance was doubtless 

 due to the continued action of the ether, which required time to 

 diffuse out of the tissue. During the next 10 minutes there was 

 a rise of 20 ohms, which was probably due, either wholly or in 

 part, to the fact that the resistance of the sea water was greater 

 than that of the mixture from which the ether had partly evapo- 

 rated. 6 During the next 400 minutes no rise occurred. The 

 results are shown in table IV and fig. 3. 



TABLE IV 













760 ] 

 850 



Sea water con- 



780 



30 



60 



800 } 

 760 



0.293M 

 ether 





80 



480 



660 1 



Sea water 



760 



This outcome is very significant, for it shows that the increase 

 of permeability produced by ether is not reversible; while, as we 

 have seen, the decrease of permeability is easily reversed. Since 

 the essential characteristic of an anesthetic is the reversibility of its 

 action, we must associate anesthesia with the reversible decrease of 

 permeability and not with the irreversible increase of permeability. 



In view of the importance of this result the experiment was 

 repeated many times, the fall of resistance (before placing in sea 

 water) varying from 50 to 200 ohms, but always with practically 

 the same result. On placing in sea water there were sometimes 

 irregular fluctuations amounting to 20 or 30 ohms but no recovery. 



