154 BENEDICT— THE INFLUENCE OF [February 4, 



the men during the mental tests and during the control periods. 

 This, to the layman, is certainly a most surprising outcome, for, as 

 you know, it is the popular impression that a sustained mental effort 

 results in a complete physical exhaustion. Here, then, is a problem 

 that is pretty thoroughly solved by means of this large apparatus 

 which had been constructed for experiments of exactly this kind. 



I ought to add here, perhaps, that incidentally among the old 

 legends that have been handed down to us and still find credence in 

 public opinion is the belief that fish is an excellent brain food. 

 This has long been wholly exploded. In fact, it has been easily 

 traced to an old saying of Professor Moleschott, — " Ohne Phos- 

 phor kein Gedanke," and as fish is known to contain phosphorus, 

 it was thought that fish was an excellent brain food for mental 

 workers. As a matter of fact, there are no researches that show 

 that there is any influencing of the chemical processes of the body 

 as a result of mental exertion. 



Of special interest, perhaps, from the standpoint of hygiene in 

 these experiments is the fact that several of the men expressed a 

 feeling of restraint and a lack of freedom to stretch themselves and 

 possibly to move about somewhat as a result of staying in the cham- 

 ber. Of course our experiments would have been seriously incon- 

 venienced if the men had moved about freely, so that we asked them 

 to diminish as much as possible all extraneous muscular exertion 

 other than that required in using the pen. This longing for the 

 use of the arms and body during mental exercise is simply another 

 means of indicating that our bodies need as perfect circulation 

 in all parts as possible, that when long-continued and cramped 

 positions are maintained, there is a feeling of uneasiness and dis- 

 comfort. 



It is a most wise and growing custom for book users to vary the 

 body position during sustained mental work. The increasing use 

 of the standing desk while reading, and the pacing of the floor 

 during mental work or dictation of addresses and literary produc- 

 tions testify to the fact that for best mental effort, there should be 

 physical exercise, though this is far from affirming that the center 

 rushes invariably become literary men. In our studying we should 

 certainly pay more attention to physical exercise and fresh air, and 



