139 



CHAPTEE XVI 



INORGANIC RESPONSE EFFECT OF CHEMICAL REAGENT 



Action of chemical reagents Action of stimulants on metals Action of 

 depressants on metals Effect of ' poisons ' on metals Opposite effect of 

 large and small doses. 



WE have seen that the ultimate criterion of the physio- 

 logical character of electric response is held to be its 

 abolition when the substance is subjected to those 

 chemical reagents which act as poisons. 



Action of chemical reagents. Of these reagents, some 

 are universal in their action, amongst which strong 

 solutions of acids and alkalis, and salts like mercuric 



Before ^ After 



FIG. 88. ACTION OF POISON IN ABOLISHING RESPONSE IN NERVE (WALLER) 



chloride, may be cited. These act as powerful toxic 

 agents, killing the living tissue, and causing electric 

 response to disappear. (See fig. 88.) It must, how- 

 ever, be remembered that there are again specific poisons 



