22 BULLETIN OF THE UNIVERSITY OP WISCONSIN. 



line, etc. Even when this salt is taken into the mouth in 

 very concentrated solution the taste is not salty. Indeed, 

 the taste is not pronounced and it is most difficult to describe 

 it in words. From the taste of sodium acetate solutions it 

 follows then, that neither Xa ions, CH 2 COO ions, nor undis- 

 sociated molecules of sodium acetate possess a strong taste. 

 The taste of sodium ions is but slight, they seem to produce a 

 smooth sensation that can not be detected in very dilute solu- 

 tions. Tins together with the fact that sodium salts are most 

 strongly dissociated admirably adapts the latter for investigating 

 the taste of anions of various kinds. Since sodium ions mi- 

 grate only 4 as fast as hydrogen ions their rate of diffusion is 

 relatively slow and this may in part account for the fact that 

 they do not affect the sense of taste more. There seems but 

 little room for doubt that in the presence of an ion of pro- 

 nounced taste, the taste of the sodium ion is completely 'masked. 



The Taste of Cathions. — The tastes of hydrogen and sodium 

 ions have already been discussed in connection with the taste of 

 the anions. To find the taste of a cathion we shall choose a 

 solution of a salt the anion of wdiich has little or no taste at a 

 dilution at which the salt is fairly nearly dissociated and at which 

 the cathion can still be tasted. 



The taste of potassium ions is rather bitter and disagreeable. 

 Solutions of the nitrate, sulfate, and acetate of potassium that 

 can be plainly tasted produce, especially on the back of the 

 tongue, a bitter and rather disagreeable taste. The correspond- 

 ing sodium salts do not produce this effect, and as potassium 

 salts even in fairly strong solution are highly dissociated, this 

 effect is to be ascribed to the action of the potasium ions. Thus 

 the individuals tested could taste KX0 3 solutions that were 

 -£; the report was that the taste of the solution was smooth, 

 alkaline (?) . In ^ solution the same taste together with a bit- 

 ter sensation was reported, while ■£ solution was found to be de- 

 cidedly disagreeable. In -^- and y£- solutions KN0 3 is disso- 

 ciated about 77 per cent, and 87 per cent, respectively; as the 

 corresponding sodium salts at these concentrations do not pro- 



