CHAPTER XVIII. 

 THE GENERAL SENSES. 



The Body a Collection of Organs. We have been 

 considering the body as a collection of organs working 

 together to serve the brain, the mechanism through which 

 the mind operates. 



We have especially studied the muscles as the only 

 means by which the mind manifests itself to the outer 

 world. 



Influences from the External World. But how much 

 mind would we have if we did not receive something from 

 the outer world ? Read the story of Kaspar Hauser. We 

 are continually getting knowledge of the outer world and 

 of the condition of our own bodies through the afferent 

 nerves. We may never know fully what consciousness and 

 thought are, but we can understand that to the brain are 

 continually streaming nerve impulses that convey messages 

 which the brain more or less completely interprets. 



Classification of the Senses. These incoming currents 

 pass along myriads of nerve fibers. But the nerve fibers 

 are all essentially alike. And the kinds of sensations that 

 these currents arouse in the brain are but few. It is diffi- 

 cult to classify the senses, but it will serve our convenience 

 to divide them into two groups. 



General Sensations and Special Senses. In distinc- 

 tion from the special senses, sight, hearing, etc., are the 



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