202 The Action of Yohimbine on Medullated Nerve 



clearly dependent on the amount of previous activity than is 

 the case when other agents are used to depress the function 

 of nerve. 



4. The anaesthetic action of yohimbine lactate as applied in 

 solution to the outside of a dissected nerve is characterised by 

 great evenness and regularity. Partly for this reason, and 

 partly because of the unusual prolongation of the refractory 

 period due to yohimbine, it has been shown that nerve is a very 

 convenient tissue on which to study the process of fatigue and 

 recovery from fatigue. 



5. In spite of the ready fatigability of 3'ohimbinised nerve, 

 complete restoration of function seems in every case to follow 

 the katabolic changes due to activity. 



6. The refractory period of nerve has been prolonged to 

 •25 second; while fatigue changes lasting for more than five 

 seconds have been demonstrated. 



The expenses of this research were defrayed by a grant from the 

 Carnegie Trust. 



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