The science of psychology has lately been coming into closer relationship with the science of medicine, and much may be expected from this connection. Psychology, the science of mental phenomena, ought surely to contribute something to medicine, which cares for the preservation and restoration of health to both body and mind. But up till recently the contributions were most frequently the other way around. The greater part of our knowledge of abnormal states of mind has been the gift of medical science to psychology. However, as the latter grows and solves some of her own peculiar problems, she will doubtless turn and try to help medicine, one of her nearest neighbors. As a sign perhaps, of such an attempt, I wish to present the results of a psychologic study of mental fatigue.
The word fatigue may mean either a fact or a feeling. By the fact of fatigue one means