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BULLETIN OF THE UNIVERSITY OP WISCONSIN. 



that one whose sleep is not undisturbed will manifest the out- 

 come in a lessened amount of vigor which may be utilized in in- 

 tellectual work. 



Some of our students preparing for examinations deprive 

 themselves of sleep altogether for three or four nights. That 

 this is a serious mistake hardly needs argument, it seems to me. 

 It is probably not only a waste of energy in the long run, but 

 really defeats the purpose for which the individual remains 

 awake; for when the mind has been driven twenty-four hours 

 without relaxation, it is not in a condition to do vigorous think- 

 ing; and if the strain be kept up throughout an entire exami- 

 nation week, the intellect must suffer in all its operations, — per- 

 ception, memory, reason, and the rest. Some experiments have 

 been made by Patrick 1 respecting the effect of prolonged absence 

 of sleep upon muscular and intellectual capabilities, and these 

 should be of interest to those students who study all night pre- 

 paratory to an examination. The charts which follow indicate 

 the increasing uncertainty in and diminution of various mental 

 and physical powers as the period of constant waking life length- 

 ens. 



IPM 



Fig. 13. — The ordinates show the number of seconds required to add a given 

 number of figures. The abscissae show the progress of the hours during the wak- 

 ing period. The last interval, however, representing the period of sleep following. 

 (Patrick.) 



*At the University of Iowa. See Studies from the Psychological Laboratory of 

 the University of Iowa, Vol. I. 



