238 SPECIAL SENSES. 



pairment of taste in animals, Bernard and others have suc- 

 ceeded in training dogs and cats so as to observe the effects 

 of colocynth and various sapid substances applied to the 

 tongue. In a great number of experiments of this kind, 

 made by Bernard, 1 Schiff, 2 and Lusanna, 3 it has been observed 

 that, after section of the chorda tympani, or of the facial so 

 as to involve the chorda tympani, the sense of taste is abol- 

 ished in the anterior two-thirds of the tongue on the side of 

 the section. However this result may be explained, the fact 

 remains, that section of the nerve in the lower animals is 

 followed by the same results as those observed in pathological 

 observations. In a remarkable case reported by Moos, 4 the 

 introduction of an artificial membrana tympani was followed 

 by loss of taste upon the corresponding side of the tongue, 

 and upon both sides, when a membrane was introduced into 

 each ear. This disappeared when the membranes were re- 

 moved, and the phenomena were referred to pressure upon 

 the chorda tympani. Experimenters are somewhat at vari- 

 ance with regard to the effects observed upon animals, some 

 asserting that the sensations of taste are simply delayed in 

 their manifestation ; but we must remember the difficulty of 

 such observations, and we are to rely mainly upon the unrnis- 



1 BERNARD, Systeme nerveux, Paris, 1858, tome ii., p. 122. 



2 SCHIFF, Digestion, Florence et Turin, 1867, tome i., p. 183. 



3 LUSANNA, Recherches experimentales et observations patJwlogiques sur les nerfs 

 du gout. Archives de physiologic, Paris, 1869, tome ii., p. 201. 



In some of the experiments referred to, it is stated that the gustatory im- 

 pression is retarded and not entirely destroyed. This is explained on the suppo- 

 sition that section of the nerve renders the mucous membrane dry", and that the 

 action of sapid substances is thereby delayed ; but it is equally reasonable to 

 suppose that, after a time, the articles are diffused and impress branches of the 

 glosso-pharyngeal. 



4 Moos, Alterations of Taste and Sensibility in the Tongue by the Application 

 of an Artificial Tympanum in a Case of Large Perforations in both Membrance 

 Tympani. Archives of Ophthalmology and Otology, New York, 1869, vol. i., p. 

 140, et seq. 



The symptoms in this case are rather indefinitely described by the patient, 

 and no very accurate observations were made. The patient also noted some in- 

 terference with the general sensibility of the tongue. 



