14th March, jgi6. 



Professor W. St. Clair Symmers, M.R., in the chair. 



iMENTAL AND PHYSICAL FATIGUE. 

 Hy Professor Valentine. 



{Abstract.) 



At the outset, a distinction was made between the sensation 

 of fatigue and real fatigue in the sense of reduced capacity 

 for work. The sensation of fatigue is a safeguard, or should be, 

 against excessive work., yet some persons do not experience this 

 sensation until exhaustion has set in. A sex difference appears 

 here, men responding more readily to the sensations of fatigue. 

 Stimulants can overcome the sensation of fatigue, with the result 

 that excessive work may be done. Dr. Rivers found that Cafeine 

 gave a spurt at first with a feeling of freshness, but a rapid drop in 

 work (physical) later. This means that sensations are deadened 

 by the drug so that we may work beyond our strength. Waste 

 products of the tissues are probably partly responsible for feelings 

 of fatigue; thus, massage by stimulating the circulation may get 

 rid of the waste products and so reduce the feeling of fatigue in 

 the muscle. 



Muscular Fatigue. 



The difificulty of calculating muscular fatigue is increased by 

 the fact that work may be shifted to new sets of muscles and so to 

 new brain cells, and so fatigue is concealed. Researchers have 

 attempted to isolate muscles, therefore, by means of the Ergograph, 

 in which only one finger works. Experiments with this instrument 

 showed that fatigue is not due to the muscle itself, for when the 

 will cannot work the finger any longer, it may be worked by 

 electrical stimulus of motor nerves. Then again, when the 

 electrical stimulus no longer works the muscle, the will may be 



