44 



HI. Is the Power of localising the Source of Sound well 

 developed ? 



Test the power of localisation by making a faint clicking 

 noise as by closing sharply a pair of forceps in the neigh- 

 bourhood of the head of the subject whose eyes are closed. 

 The latter must make a definite statement as to where the 

 sound comes from. 



VI. HAVE WE THE POWER OF DETERMINING 



THE POSITION AND MOVEMENTS OF THE 

 VARIOUS PARTS OF OUR BODIES? 



METHODS. With the eyes closed, (a) put the various parts 

 of the arm, hand and fingers in any position, and try if the 

 position of each part can be determined ; (6) get some one 

 to put the same parts in any position, and again try if the 

 positions can be accurately described. 



(c) Take a weight in the hand and study how an estimate of 

 the weight held is arrived at. Has the condition of the 

 muscles, tendons, and joints anything to do with it, and if 

 so, what ? This may be called the MUSCLE-JOINT SENSE of 

 weight. 



To test this sense find the smallest difference of weight 

 which can be detected, as in Appreciation of Pressure, p. 31, 

 II., but keeping the hand free of the table and using the 

 muscles of the arm. 



(d) By passing the hand over some object with the eyes shut, 

 study how this sense, in conjunction with touch, gives informa- 

 tion as to the distance, shape and size of external objects. 



VII. HAVE WE THE POWER OF DETERMINING 

 THE MOVEMENTS OF THE BODY IN SPACE? 



Consider the absence of sensation of movement in smooth - 

 running trains, and the sensation of movement on starting and 

 stopping. 



