118 RESPONSE IN THE LIVING AND NON-LIVING 
CHAPTER XIV 
INORGANIC RESPONSE—FATIGUE, STAIRCASE, AND MODIFIED 
RESPONSE 
Fatigue in metals—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 

Fic. 69.—FaticguE In Musciue Fic. 70.—FatTIcuE IN 
(WALLER) 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 
