n8 RESPONSE IN THE LIVING AND NON-LIVING 



CHAPTEE XIV 



INORGANIC RESPONSE FATIGUE, STAIRCASE, AXD MODIFIED 



RESPONSE 



Fatigue in nietals Fatigue under continuous stimulation Staircase effect 

 Reversed responses due to molecular modification in nerve and 

 metal, and their transformation into normal after continuous stimula- 

 tion Increased response after continuous stimulation. 



Fatigue. In some metals, as in muscle and in plant, 

 we find instances of that progressive diminution of 

 response which is known as fatigue (fig. 69). The 

 accompanying record shows this in platinum (fig. 70). 

 It has been said that tin is 

 practically indefatigable. We 

 must, however, remember that 

 this is a question of degree 



FIG. 69. FATIGUE IN MUSCLE 

 (WALLER) 



FIG. 70. FATIGUE IN 

 PLATINUM 



only. Nothing is absolutely indefatigable. The exhi- 

 bition of fatigue depends on various conditions. Even 

 in tin, then, I obtained the characteristic fatigue -curve 

 with a specimen which had been in continuous use for 



