The Special Senses 241 



surface of the body touched. As we all know, the sense 

 of touch varies in different parts of the skin. It is most 

 acute where the outer skin is thinnest. The tips of the 

 fingers, the edges of the lips, the forehead, and the tip of 

 the tongue are especially sensitive. 



.372. How the Sense of Touch may be educated. The 

 sense of touch is capable of education and may be devel- 

 oped to an extraordinary degree in persons who are deprived 

 of some other special sense, as sight or hearing. We read 

 of a famous blind sculptor who was said to model excel- 

 lent likenesses, guided entirely by the sense of touch. An 

 eminent authority on botany was a blind man, able to dis- 

 tinguish rare plants by the fingers and by the tip of the 

 tongue. The blind learn to read with facility by passing 

 their fingers over raised letters. 



It is impossible to contemplate, even for a moment, the 

 prominence assigned to the sense of touch in the physical 

 organism, without being impressed with the manifestations 

 of design, the work of an all-wise Creator. 



^ Experiment 103. To illustrate how the sense of touch is a matter 

 of habit or education. Shut both eyes and let a friend run the tips 

 of your fingers, first lightly, over a hard plane surface ; then press 

 hard, then lightly again, and the surface will seem to be concave. 



? Experiment 104. Cross the middle finger over the index finger, 

 roll a small marble between the fingers ; one has a distinct impression 

 of two marbles. Cross the fingers in the same way and rub the 

 crossed ends against the point of the nose. A similar illusion is 

 experienced. 



/ Experiment 105. To test the sense of locality. Ask a person to 

 shut his eyes, touch some part of his body lightly with the point of 

 a pin, then remove it, and ask him to indicate the part touched. 



373. Muscular Sense. When a heavy object is laid upon 

 ' certain parts of the body it produces a sensation of pressure. 



