EXPERIMENTATION AND PHYSIOLOGY 



neurologist differentiates the location of the 

 lesion between ataxic aphasia (that condition 

 in which words can be remembered but can not 

 be spoken) and amnesic aphasia (the condition 

 in which words can be spoken but can not be 

 remembered). 



This scientific study of the nervous system 

 has been founded upon animal experimenta- 

 tion. The discovery of the property of nerves 

 has depended on it. Certain nerves are incapa- 

 ble of feeling pain; and others are highly en- 

 dowed with this property. For example: the 

 two nerves distributed to the face, which are 

 known respectively as the tri facial and the 

 facial, may be taken. They are alike in their 

 external appearance, even under the micro- 

 scope they have similar structure. By ex- 

 amining the trunks of these nerves in the dead 

 body the anatomist could not detect an essen- 

 tial difference between them. But experiments 

 conducted upon the living animal show that 

 their actions are very different. The trifacial 

 is a nerve of sensation and supplies the face 

 with feeling. It is the nerve involved in facial 

 neuralgia. The facial is a motor nerve and 

 gives power to the muscles of the face. The 

 old mistake of dividing a motor nerve, with 

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