TASTE 401 



VII 



TASTE 



Threshold Value. Prepare solutions of cane 

 sugar of the following strengths : 1 : 1000, 1 : 800, 

 1 : 600, 1 : 400, 1 : 200, 1 : 100. Take half a 

 teaspoonful of the weakest solution into the 

 mouth, roll it upon the tongue, arid swallow 

 it. Note whether a sweet taste can be per- 

 ceived. Rinse the mouth thoroughly. Proceed 

 with solutions of increasing strength until the 

 sweet taste is just perceptible. 



Topography. 1. Select a solution of sugar 

 slightly more concentrated than that just per- 

 ceived to be sweet. With a small camel's-hair 

 brush apply this solution to the several parts 

 of the tongue and the palate. Determine the 

 regions sensitive to taste. The mouth must be 

 rinsed frequently. 2. Dry the upper surface of 

 the tongue with a handkerchief. With a finely 

 pointed camel's-hair brush apply a twenty per 

 cent sugar solution to the individual fungiform 

 papillae and to the mucous membrane between 

 them. Determine whether only the papillae 

 perceive taste. 



Relation of Taste to Area stimulated. Swallow 

 a very small quantity of a minimal solution of 

 sugar, as determined in the experiment upon 

 26 



