REST AND ACTIVITY. 233 



As a matter of interest it may be noted that 

 forces, such as the sound of soothing music, may 

 produce an inhibition of movements. Music may 

 cause a man to keep quiet and rest. As a matter 

 of speculation it seems to me probable that when 

 the kinetic function of the nerve-mechanism is in 

 abeyance the trophic action prevails, and more 

 nutrition takes place. One reason for this view, 

 among many others, is that a general good state of 

 nutrition of the body promotes rest. Conditions 

 of ill nutrition are often accompanied by signs of 

 irritability. 



In contradistinction to the state of rest we have 

 activity. The condition of activity is indicated by 

 actions, i.e. movements. In activity with strength, 

 the movements are probably fewer in number than 

 in the state of irritability, and the combinations 

 and sequences of movement differ in the two con- 

 ditions. 



Healthy activity is indicated by a quick response 

 of movement upon stimulation,, that is to say, for 

 example, that the movement follows quickly upon 

 *the sight of an object or on hearing a sound. 

 If such movements are looked upon as reflex 

 actions, the quick and ready answer is a reflex 

 series of movements where the period of latency is 

 short. This,, of course, implies also that impression- 

 ability is good. 



Impressionability, as a property of the nerve- 

 mechanism, is especially interesting as being an 

 essential factor among the properties of the brain 

 necessary to mentation. In the first two chapters 



