ANIMAL AND VEGETABLE 233 



measure of the nerve-current in it as compared with the 

 nerve- current present in the auditory nerve of a healthy 

 person of similar hand-to-hand deflection. If it is partially 

 atrophied the first step should, I think, be to restore it to 

 its normal condition of an active closed circuit ; by, say, 

 ionic medication. 



In the case of catarrh of the middle ear, or of the 

 presence of inspissated mucus in the middle ear, our object 

 should be to introduce a harmless solvent into what is, 

 practically, a closed cavity. 



