86 PHYSICAL BASIS OF CIVILIZATION 



finger towards any can be changed in many ways. 

 This practically infinite variety of relations and 

 positions undergoes infinite multiplication by the 

 opposability of the shorter, thicker, more sensitive 

 thumbs. These hands, these fingers, thumbs, and 

 their extreme ends are covered with a highly plastic 

 and equally elastic material, replete at its outer 

 surface with highly sensitive nerve filaments and end 

 bulbs, etc., susceptible to every kind of touch, from 

 the infinitesimal ether vibrations called heat, elec- 

 tricity, etc., to the violent collisions with hard and 

 sharp objects. 



As a means of educating and forcing the growth 

 of intelligence, the superiority of this kind of touch 

 over that residing in the end of a nose just above 

 a prognathous mouth is so vast that comparison 

 seems impossible. 



Then consider that the attaching sockets of the 

 large levers operating this human sense of touch 

 are in adults situated about five feet above the 

 ground, in a place favorably located for deriving 

 the utmost advantage from guidance and correc- 

 tion by and co-operation with the senses of sight, 

 hearing, smell, and taste. 



Adults who have been blind and who then receive 

 their sight are at first only confused and made 

 helpless by the lights, shadows, colors which they 

 perceive. They cannot interpret them. They have 

 to be taught by others the nature of the things 

 indicated by the lights, shadows, color, which they 



