228 PHYSICAL EXPRESSION. 



not uncommon during sleep to find the condition of 

 muscular tone different on the two sides of the 

 body. We commonly say there may be different 

 depths of sleep ; sleep may be full and complete, 

 with loss of most forms of impressionability. Ob-! 

 jective observation of a subject during apparent 

 sleep does not necessarily give evidence as to 

 whether there be any impressionability or not ;. 

 it may be found that the outcome of impressions, 

 received is long delayed. Things said before a 

 child apparently asleep may not produce any 

 visible result at the time, but we may subsequently 

 learn that it was impressionable to sound at the 

 time of observation; the child may tell us what 

 was said before it. Here we know the impres- 

 sionability by its effects in subsequent speech 

 (movements). 



Fatigue is indicated by the slight amount of 

 force expended in movement, and by the small 

 number of movements. In the latter character we 

 see some distinction between fatigue and irrita- 

 bility, in which condition there is often an excess 

 of movement, and in particular an excess of speech. 

 Fatigue and irritability often coexist. The volun- 

 tary movements are apt to become uncertain, as 

 is illustrated by the change of handwriting when a 

 man is tired. The free hand assumes the " straight 

 extended posture with the thumb drooped,"- or the 

 posture of the feeble hand. The head is often in 

 an asymmetrical posture, and flexed. The direct 

 effects of gravity determine the position of the 

 body to a greater extent than in the condition of 



