DUAL CHARACTER OP THE BRAIN. 21 



that even adults can come to make use of their left arm. A 

 person who has lost his right arm can learn to write (with 

 difficulty, it is true, because in adult life it is much more diffi- 

 cult to produce these effects than in childhood), and the left 

 arm can be used in a great variety of ways by persons who 

 wish to make use of it. It is perfectly well known that the left 

 arm is employed in pla^'ing on the piano or on certain other 

 instruments almost as well as the right arm. Therefore there 

 is no difficulty in training children to make use of both sides 

 of the body equally. 



There is also another fact as regards the influence of training. 

 Even in adults, who have lost the power of speech from disease 

 of the left side of the brain, it is possible to train the patient to 

 speak, and most likely then, by the use of the right side of the 

 brain, the left side of those patients, with great difficulty, will 

 come to learn. They always have more difficulty than do 

 children, but they learn if they are taught in the same way. It 

 is the same kind of teaching that we employ for a child when 

 we try to make it speak; it is the same way that should be em- 

 ployed to teach an adult who has lost the power of speech. It 

 is so, also, as regards gesture, and the rest. I have trained 

 some patients to make gestures with the left arm, who had lost 

 the power of gesture with the right, and who were quite uncom- 

 fortable because their left arm, when they tried to move it, at 

 times moved in quite an irregular way, and without any 

 harmony. There is an aptness acquired by training, therefore, 

 even in adults, and, if so, that capacity exists in children, and 

 as we well know that we can make a child naturally left-handed 

 to become right handed, in the same way we can make a child 

 who is naturally right-handed to be left-handed also. But the 

 great point should be to equall3^ develop the two sides. To 

 point out this has been the principal object of this lecture ; and 

 I have now to thank you for having listened to these long and 



tedious details. 

 35 



