9 o RESPONSE IN THE LIVING AND NON-LIVING 



that KHO in minute quantities is an excitant, while in 

 large quantities it is a depressant. 



We have thus seen that we may obtain response 

 (1) by block method, (2) by the method of injury, or 

 relative depression of responsiveness of one contact, 



fa,) ft) fc) fd) 



r v 



A 



IV 



i 

 i 

 .j 



FIG. 54 



Perma- Current 



nent of 



Current Response 



B treated with so- 

 dium carbonate . 



B treated with ox- 

 alic acid 



B treated with very 

 dilute potash 



B treated with 

 strong potash 



Current of response is always towards 

 the more excitable point. 



(a) Response when B is treated with 



sodium carbonate. An apparent 



positive variation. 

 (6) Response when B is treated with 



oxalic acid. An apparent negative 



variation. 



(c) Response when B is treated with 



very dilute potash. Positive varia- 

 tion. 



(d) Response when B is treated with 



strong potash. Negative variation. 



The response is up when B is more ex- 

 citable, and down when A is more 

 excitable. 



Lines thus indicate deflection due 



to permanent current. 



and (3) by the method of relative exaltation of 

 responsiveness of one contact. In all these cases alike 

 we obtain a consistent action current, which in tin 

 is normally positive, or towards the relatively more 

 excited. 



