PHYSIOLOGY OF GUSTATION 147 



the two persons experience different sensations, one sour 

 and the other alkaline. These and other like experi- 

 ments led Eosenthal to conclude that the electric current 

 itself was the stimulating agent and not the materials 

 produced by electrolysis. 



But it must not be forgotten that the electrical stimu- 

 lation of organs of taste is productive of a variety of 

 sensations. Thus in 1798 Bitter showed that after a cur- 

 rent had been passing for some time through the tongue 

 the sour taste of the anode changed first to bitter and then 

 to alkaline while the cathodic alkaline taste changed to 

 sour. Hofmann and Bunzel (1897) demonstrated that 

 during the passage of a current there is at the cathode 

 a burning bitter sensation which changes to a sour metal- 

 lic taste on breaking the current. The initial taste they 

 believed to be due to the products of electrolysis. Von 

 Zeynek (1898) also accepted this explanation for the elec- 

 tric taste. Gertz (1919), however, pointed out that the 

 alternating current is really more effective in exciting 

 taste than the direct current and that hence the electric 

 taste may be aroused by other means than the products 

 of electrolysis. It is not at all impossible that the gusta- 

 tory organs may be excited in both ways : by the materials 

 of electrolytic decomposition and directly by the electric 

 current. But how an electric current can stimulate gus- 

 tation without in some way bringing about a chemical 

 change, at least within the gustatory cell, is difficult 

 to imagine. 



The extreme sensitiveness of the organs of taste to 

 electrical stimulation is not only characteristic of man, 

 but is probably found throughout the vertebrates. 

 Among fishes the catfish or horned pout, Amiurus, is ap- 



