266 Proceedings of the Royal Irish Academy 



In the second place, I do not believe we can accept the purely 

 mechanical view of the cleaning of the tongue which Mr. Bultin has 

 embodied in these words : " The tongue is kept clean by free move- 

 ment, and by being rubbed against the interior of the mouth, gums, 

 and teeth . . . the fur is generally thickest in the morning, and dur- 

 ing illness, when the necessary cleansing is not properly performed." 

 It is scarcely necessary to remark that the state of the tongue varies 

 much in disease, and that even in the course of one affection, e. g., 

 typhoid fever, it may alter considerably in appearance. Again, in 

 some disorders, when there is no reason to suppose the tongue unduly 

 active, it becomes, so to speak, abnormally clean and red. 



If the proposition laid down were correct, then we should expect 

 to see the tongue furred in proportion to its inactivity. This, how- 

 ever, is not so. In the case of Mr. L , that side of the tongue 



from which the fur first cleaned off was precisely the side which was 

 paralysed as regards movement, and owing to the facialis paralysis, 

 the cheek had fallen away, flaccid, and did not press the food into the 

 cavity of the mouth, and towards the tongue, as was normally done on 

 the right side, where the fur, in spite of all friction, remained per- 

 sistently. Again, in cases where the tongue is more or less com- 

 pletely deprived of the power of motion, by paralysis or atrophy, it 

 should, if this theory held good, be thickly coated with fur. But the 

 fact is that the active tongue of (say) a scarlatina patient will be heavily 

 loaded, whilst the motionless tongue of a paralytic may be free, or 

 at least present no abnormal appearance. In labio-glosso-laryngeal 

 paralysis the tongue remains, at a certain stage, motionless, and yet, 

 as I can testify, it is not necessarily loaded. In this disease, first 

 described by my regretted master. Dr. Duchenne (de Boulogne) the 

 debility of the tongue is accompanied by an accumulation of viscous 

 saliva, as he observes, but he distinctly points out that, "neverthe- 

 less, neither redness nor any alteration whatever of the buccal or 

 pharyngeal mucous membrane is to be remarked." * Professor Char- 

 cot, in his great work on Diseases of the !N^ervous System, describing a 

 case of glosso-laryngeal paralysis,^ mentions that the patient could no 

 longer make herself understood, the only sound she could produce 

 being a nasal grunt : she could, indeed, protrude her tongue, and 

 move it from side to side, but she could neither turn up the tip, nor 

 apply its dorsal surface to the palate, — thus she could not rub it. 

 Nevertheless, the tongue appeared quite normal. It is useless to 

 multiply instances : enough has been said to prove that the production or 

 removal of fur does not depend, to any marked extent, on the less or 

 greater power of motion possessed by the tongue. 



I have already indicated that, when the nerve-action is enfeebled 

 or paralysed, the vitality (so to speak) of the corresponding region is 

 lowered, and the tissue then becomes less able to resist the activity of 



* Duchenne de Boulogne, Be V Electrisation localisee, p. 568: Paris, 1872. 



* Charcot, Lemons sur les Maladies du Si/steme Nerveux, p. 426 : Paris, 1877- 



