SPECIAL SENSES 105 



room-topped (jwngiform), and large and wartlike (circum- 

 vallate). Draw an outline of the tongue and locate on it 

 the regions where these different forms are to be found. 



LXVIII. SENSATIONS OF TASTE AND SMELL. 



Apparatus. Onion, sugar, salt, vinegar, dilute ammonia, quinine. 



Directions. A. Location of Taste. Wipe the tongue 

 dry and place on its tip a little dry sugar. Has it any taste? 

 Let it dissolve. Has it any taste now? Repeat, placing 

 the sugar at the back of the tongue. Is its sweetness more 

 or less prominent? Repeat again, using quinine, vinegar, and 

 salt successively. Where are the sensations of bitterness, 

 sourness, and saltiness most prominent? 



B. Taste and Odor. Examine the various substances 

 named under " Apparatus." Which have taste? odor? 

 Place each of these substances on the tongue of a pupil 

 who has been previously blindfolded, and who is holding 

 his nose tightly. Record the substances recognized by 

 taste alone. Repeat, leaving the nose free but retaining the 

 blindfold. Record those substances recognized by smell 

 alone; by taste and smell combined. 



LXIX. HEARING; LAWS OF SOUND (OPTIONAL). 



Apparatus. Stretched wire, bridge to shorten length. 



Directions A. Strike the wire. Do you get any sound? 

 What is the wire doing? All sound depends upon vibra- 

 tion : test several sounding bodies to verify this statement. 



B. Move the bridge to the middle point of the wire and 

 strike again. Is the pitch higher or lower? Does a short 



