92 NERVOUS SYSTEM, 



Q. How are the external sensations divided ? 



4#. Animal sensibility with regard to external sensa- 

 tions is general and particular. The general refers to 

 impressions made by bodies on the external surface. The 

 particular relates to the sensibilities of particular organs 

 to peculiar impressions, as the eye to light. 



Q. But have not some organs of animal life both gene- 

 ral and peculiar animal sensibility? 



*ft. They have. For instance, the tongue may feel the 

 impression of a substance, without the sense of taste being 

 excited. The nerves of general and peculiar sensibility 

 are absolutely distinct. 



Q. How does opium relieve pain? 



/?. By suspending the action of the brain, so that nei- 

 ther external nor internal sensations are perceived. 



Q. Do the nerves possess animal contractility? 



A. Not at all; that property appertains to the muscles. 



Q. What agency then have the nerves in the muscular 

 animal contractility? 



Ji. They transmit the principle of motion. In animal 

 contractility there are three agents; viz. the brain that 

 wills, the nerve conveying cerebralvolition, the muscle 

 which obeys in action. 



Q. Do the nerves exercise much organic contractility 

 and sensibility? 



<flL. They do not. They exercise these properties of 

 life so far as nutrition requires them. The nerves abound 

 with animal sensibility. 



Q. Is there a difference in the size of the nerves of a 

 sound and paralytic side? 



#. They are alike. The nerves are not affected in 

 many diseases. Their nutrition goes on, and organic 



