THE SENSE OF TASTE 



515 



/ 2 3 

 Homentrvtion der SHuren. 



5 6 7 



Mi III mo/ in II 



[HJCHiCOOH 



(H-)COOHCH(OH)CII(0/I)COOH 

 fl^Hi C03> 1— I 



FIG. 8. Equal sourness matches. Ordmates give concentrations of HC:l required to match the sour- 

 ness of other acids at concentrations shown on the abscissae. Broken lines give hydrogen ion concen- 

 trations of weak acid and salts. [From Paul-Munchen (158).] 



FIG. 9. Integrated response of the rat chorda tympani nerve to hydrochloric, citric, formic, ox- 

 alic, acetic and hydrochloric acids ^reading from left to rig/it') at pH 2.5. Duration of response, 10 to 

 20 sec. [From Beidler (20).] 



