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LABORATORY EXERCISES. 



45. SENSATION OF TOUCH. 



Materials: Pen and ink, pin, ruler, pair of scissors. 



A. Blindfold a person, touch lightly some portion of 

 his body with a pen dipped in ink, and ask 

 him to point out with a pin the point touched, 

 as soon as you have removed the pen. 



1. Measure the distance with a rular between 



the ink-dot and the point touched with 

 the pin. Record result as directed be- 

 low in 4. 



2. Try the experiment several times on the 



same region of the body. Do the results 

 agree ? 



3. Try the experiment on different parts of the 



body. 



4. Record results in tabular form as follows: 



B. Apply lightly the points of a pair of scissors (sep- 

 arated about a quarter of an inch) to the palm 

 of your hand. 



1. Can the points be felt as two, or do they feel 



as one ? 



2. Separate the points of the scissors a little 



more than a quarter of an inch, and ap- 



