202 ALBERT M. REESE 



tion was then used in the same way, w 7 ith the same negative 

 result. It was then concluded that the skin of this salamander 

 is, like the human skin, and unlike that of the dogfish, not sus- 

 ceptible to cocaine when applied superficially as may be done 

 with a mucous membrane. 



Experiment 10. In hopes of being able to distinguish between 

 the sense of smell and that of taste a 5% solution of cocaine 

 was used in the manner about to be described. Owing, however, 

 to the fact that the posterior nares, as in the frog, are compara- 

 tively wide and are situated far forward in the roof of the 

 mouth, it is probable that in this experiment the cocaine that 

 was used in the mouth always affected the nasal chamber about 

 as much as it did the oral mucous membrane; and that, as was 

 said above, when the cocaine w r as applied to the anterior nares 

 it leaked down into the mouth. 



Since the anterior nares are very minute, scarcely large enough 

 to admit an ordinary pin, it was useless to try to stop them up 

 with cotton as did Sheldon (9) in his experiments upon the sense 

 of smell in the dogfish. 



The results obtained in this experiment were, as will be seen, 

 somewhat conflicting, but they will be described as briefly as 

 possible. An animal that snapped vigorously at a bit of meat 

 was removed from the water and a small wad of raw cotton 

 saturated with 5% cocaine, was put into its mouth and held 

 there for about two minutes. The animal was then returned to 

 the water and offered the bit of meat.; it paid no attention what- 

 ever to the meat, though it was presented to its nostrils at inter- 

 vals of from ten to sixty minutes during the next seven ho.rs. 

 It also responded very slowly and weakly to 1 % acetic acid dur- 

 ing the first half hour after the removal of the cotton from the 

 mouth. 



Another animal that also snapped quickly at a bit of meat, 

 thus showing that it was hungry, was removed from the water 

 and a wad of clean raw 7 cotton, wet with pure water, was put 

 into its mouth as was done with the cotton wet with cocaine in 

 the first animal. On being replaced in the water this animal 

 immediately snapped at the meat, and did so again at the end 

 of ten minutes; this seemed to indicate that the raw cotton 

 had no effect upon the feeding habits of the animal. The cotton 

 was now soaked in 5% cocaine and again introduced into the 



