in THE SENSE OF TASTE 147 



elementary qualities of taste can be elicited by the action of the 

 ions on the gustatory nerve-endings. Hober and Kiesow believed 

 that by comparing the tastes of the solutions of a great number 

 of electrolytes the taste of many kinds of ions and molecules 

 could be determined. But this would not explain the origin of 

 the different qualities of taste, because nothing is known about 

 the relation of the latter to the peripheral taste organs on which 

 sapid substances act. Still it is shown by the work of these 

 authors that the compound taste of many substances results from 

 the sum of the tastes of their individual components, broken up 

 by the dissociative force of the water. 



Herlitzka arrived at somewhat different results. On examining 

 the taste of over seventy salts he came to the conclusion that 

 the taste of the salts was due to the free ions and not to non- 

 dissociated molecules, and in confirming the conclusions of Kichard 

 and Kahlenberg that the acid taste is due to hydrogen ions, and 

 of Hober and Kiesow that the aajt taste, is dependent on the 

 anions, he affirms that the elementary kations (excepting, of 

 course, the hydrogen ions) have a sweet or bitter taste, or both 

 together. The taste of a salt would thus result from the conflict 

 between the taste of the anions and of the kations, some salts! 

 having only the taste of one, some of the other, some of both. 



Attempts have also been made to determine the relations 

 between different tastes and the relative position of the atoms 

 and the various groups of atoms in the molecule. We are mainly 

 indebted to Haycraft (1887), Sternberg (1898-1903), and Herlitzka 

 (1908-9) for these interesting researches. 



Haycraft found that the molecular weight of a substance, 

 even if it affects the intensity of a taste, has no important 

 influence upon quality of the taste sensations. On the contrary, 

 the different groups of Mendeleeff's system show a marked agree- 

 ment in their gustatory qualities. The chlorides of the first 

 group (Li, Na, K, Cu, Kb, Ag, Cs, Au) all have a salt taste, while 

 the sulphates have a bitter-sweet taste. The chlorides of the 

 second group (Mg, Ca, Zn, Sr, Cd, Ba) are bitter-salt, except the 

 salts of beryllium. The chlorides of the seventh group (I, Cl, On, 

 Br), again, have a bitter taste. Another fact discovered by 

 Haycraft is that the organic compounds containing the group 

 COOH have an acid taste; the alcohols, with the exception of 

 the lowest members of the series, are sweet. 



Sternberg, too, attempted to ascertain the relations between- 

 given groups of molecules and certain tastes. He called these 

 groups sapiforous, and included in them the groups OH, NH 2 , 

 N0 3 , which in various combinations of the organic molecules 

 have different tastes. 



Herlitzka took up the relations between the taste of the ions 

 and their position in Mendeleeff's periodic system, and pointed 



: 



