KAIILENBERO — ACTION OF SOLUTIONS ON TASTE. 31 



intense is the taste; but there are many exceptions that show 

 that the intensity of the taste produced by the ions is not simply 

 determined by the readiness with which they can get at the 

 nerve endings, but also by the reactions they undergo with the 

 protoplasm, which of course are determined by the chemical 

 character of the ion. 



9. The intensity of the taste of solutions of substances con- 

 taining amido-acid, acid-amido, alcoholic hydroxyl, and aldehyde 

 groups was investigated, and it was found that the results, ob- 

 tained are in general such as one would expect viewing the mat- 

 ter simply in the light of Overton's determinations of the rel- 

 ative readiness with which these substances permeate plant and 

 animal membranes. 



10. It was pointed out that in general the alkaloids have a 

 pronounced bitter taste, that according to Overton nearly all 

 permeate protoplasm readily and that furthermore, they are 

 known to exert a strong physiological action on the nerves. 



11. Colloidal solutions are tasteless because the substances 

 they contain diffuse very slowly and are chemically very inert. 



Laboratory for Physical Chemistry, 



University of Wisconsin, 



Madison. 



