1901.] on the Response of Inorganic Matter to Stimulus. 



637 



students of physiological response but also in medical practice, that 

 of the opposite effects produced by the same drug when given in large 

 or in small doses. Here too we have the same phenomena reproduced 



Before 



After 



Fig. 17. — Photographic record, showing the killing action of 

 strong dose of KHO (1 per cent.) on tin. The electric response 

 is abolished after the application of potash. Compare the effect 

 of KHO on nerve in Fig. 18. 



Before 



After 



Fig. 18. — Killing action of KHO on electric response of nerve (Waller). 



in an extraordinary manner in inorganic response (Fig. 20). The 

 same reagent which becomes a poison in large quantities may act as 

 a stimulant when applied in small doses. 



