CHAPTER XIV
INORGANIC RESPONSE—FATIGUE, STAIRCASE, AND MODIFIED RESPONSE

Fig. 69.—Fatigue in Muscle (Waller)

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 only. Nothing is absolutely indefatigable. The exhibition 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 many days ([fig. 71]). While discussing the subject of fatigue in plants, I have adduced considerations which showed that the residual effect of strain was one of the main causes for the production of fatigue. This conclusion receives independent support from the records obtained with metals.

Fig. 70.—Fatigue in Platinum