HERMANN VON HELMHOLTZ 



than that of the drumhead, and thus effective, but 

 very minute, pushes to and fro are communicated to 

 the delicate structures in the inner ear. Helmholtz 

 also investigated the little saddle-shaped joint between 

 the incus and the head of the malleus, showing 

 that when the drumhead was pushed in very strongly 

 there was a curious rotation of the surfaces of the 

 bones so that they interlocked, and thus further 

 pressure could not be communicated to the stapes ; 

 while, on the other hand, if the drumhead was 

 distended outwards, as by inflating the tympanum 

 through the Eustachian tube, there was no danger of 

 pulling the base of the stapes out of its place, because 

 the little joint opened up, the head of the malleus 

 swinging free from the depression in the incus. 

 Thus the danger of injuring the inner ear by violent 

 movements of the drumhead, either outward or 

 inward, is reduced to a minimum by these exquisite 

 arrangements. In this investigation Helmholtz proves 

 to the hilt his claim to be a competent anatomist. 



It was, however, in the region of the internal ear 

 that Helmholtz won for physiological science the 

 greatest triumphs. Up to the date of his investigations 

 this was known almost solely to the anatomists, who 

 laboriously described its various parts and covered it 

 over with a barbarous terminology, which is still the 

 terror of students. The physiologists had little to 

 say as to its probable functions, and the mathe- 

 maticians and physicists and writers on acoustics 

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