156 BULLETIN OF THE UNIVERSITY OF WISCONSIN. 



after knowledge, and which retains from day to day the respira- 

 tory contributions of its occupants, is, to say the least, a poor 

 mount on which to entertain the Muses. Libraries in which 

 the atmosphere is rarely changed furnish occasion for idle and 

 even stupid gazing at books; one cannot drink deeply at the 

 Pierian spring in such a place. Morrison 1 has well said that 

 in a comfortable atmosphere of proper temperature and purity 

 as much labor can be accomplished in one hour as can be accom- 

 plished in six hours in an atmosphere rendered impure by respi- 

 ration. 



* 



§ 2. Exercise. — Doubtless every one is familiar with the most 

 important effects of physical exercise upon the somatic func- 

 tions. Hygiene has taught us these many years that muscular 

 activity quickens circulation, stimulates the organs of elimina- 

 tion, arouses lethargic cells in all parts of the body, creates 

 a need for oxygen which results in increased respiration ; and, 

 in short, produces a general feeling of euphoria, of well-being, 

 which must be of distinct advantage to the organism from what- 

 ever point of view it is regarded. That which heightens the 

 tide of life as a whole must be considered as fostering more 

 vigorous and efficient mentation ; so that if exercise produced 

 directly only physiological effects in the organism, it would 

 still be of inestimable benefit to the mind. But there are other 

 .ways in which it is of marked advantage to the mental life. 

 For one thing, it relieves muscular tensions which sap the vital- 

 ity of the physical medium of mind, a matter which will be 

 discussed at length later. 2 The point which must receive 

 special attention here relates to the value of exercise in pro- 

 moting metabolism in the cerebral motor areas, and hence in 

 augmenting the total energy-producing capacities of the brain. 

 According to a now prevalent view of which Flechsig 3 is the 

 most illustrious exponent, energy generated in one nerve cen- 



1 The Ventilation and Warming of School Buildings. 

 2 Chap. X. 



s See Gehim und Seele. See also Curtis: Inhibition, Pedagogical Seminary, 

 Vol. VI, No. 1 ; Burk. op. cit., and Newsholme, School hygiene, Chap. XII. 



