XX. 



SOME DERMAL SENSATIONS. 



Touch, Smell, and Taste. 

 A. The Sense of Touch. 



I. LOCATION OF TOUCH. 



Close the eyes and have some one touch some part of 

 the body. Can you name the part touched? 



II. THE SENSIBILITY OF THE SKIN. 



Apparatus. A pair of dividers. 



Apply the blunted points of a pair of dividers simul- 

 taneously to some part of the body, as the finger tips, the 

 back of the hand, and the back of the neck. Determine 

 the distance between the two points that is necessary in 

 order that the points may be felt as two. Compare your 

 results with those given in any physiology. 



III. ARISTOTLE'S EXPERIMENT. 



Cross the middle finger over the forefinger, and with 

 the crossed ends rub along the bridge of the nose. What 

 is the sensation felt? 



B. The Sense of Temperature. 



Materials. Iron rods. Pieces of fur, silk, wood, and metallic 

 rods. Water. 



Apparatus. Bunseii burner. Large beakers or basins. 



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