in THE SENSE OF TASTE 157 



organs are altered in much the same way as by sulphuric acid, so 

 that pure water tastes sweet. 



Another interesting fact was noted by Zuntz and Heymens to 

 the effect that a solution of sodium chloride and quinine, so weak 

 as not to arouse any distinct taste, is still sufficient to exaggerate 

 the taste of a solution of sugar. 



There is at present no really satisfactory solution of these 

 facts, which correspond more or less to contrast phenomena, but 

 they do not appear to favour Oehrwall's theory, but rather to 

 support that of a single gustatory sense. Kiesow, moreover, 

 holds that Oehrwall's theory is contrary to direct experience, and 

 brings out the psychological fact that the different gustatory 

 qualities, however they may differ among themselves, have none 

 the less something in common which distinguishes them collectively 

 from every other category of sensation. 



In defence of his theory that the four elementary tastes 

 correspond to four distinct sense-organs, Oehrwall also questions 

 the phenomena of compensation. He holds that on mixing two 

 or more tastes (except when new chemical compounds arise from 

 the mixture) it is not possible to form a new taste, and that 

 the taste of the ingredients can always be recognised in the 

 mixture. 



Briicke expressly stated that some gustatory sensations are 

 able to compensate each other respectively, without thereby 

 reciprocally neutralising the stimulating substances. But the 

 instances he adduced are not convincing, nor are they comparable 

 with the results obtained by mixing two complementary colours 

 which neutralise each other and yield the sensation of white. 

 Sugar compensates or corrects the bitter taste of coffee and the 

 ^ acid taste of lemonade, but not in the sense of producing a new 

 taste. Both tastes persist, and there is a mixed and more agree- 

 able sensation. Sensations of contact, again, may obscure or 

 modify the affective tone of a sensation, e.g. mustard and pepper 

 frequently do so. \ 



The clearest example of a cpjngensatory effect in gustatory 

 sensation is mentioned by Kiesow, who, on mixing weak solutions 

 of sugar and salt in a certain ratio, obtained an insipid alkaline 

 taste which recalled neither sugar nor salt. If more concentrated 

 solutions are mixed the phenomenon of compensation is no longer 

 apparent. If a mixture of two substances is taken into the mouth, 

 one strongly sweet, the other bitter, various sensations are per.- 

 ceived at different times and on different spots of the tongue, 

 some bitter and others sweet. 



Kiesow saw that on combining the majority of primitive tastes 

 in certain proportions, but always very dilute (sweet and salt, 

 sweet and acid, sweet and bitter, salt and acid, salt and bitter, 

 acid and bitter), they are respectively diminished in different 



