Sound Waves by the Cochlea. 



353 



instance, if one squeezes A gently and slowly there is a move- 

 ment of liquid in the far limb of the U and also rapid 

 oscillations in the tube nearest to A. These rapid oscilla- 

 tions are due to irregularities in the muscular contraction, 



Fisr. 3. 



Diagram of apparatus for the analysis of pressure waves. 

 A = rubber bulb for producing' pressure variations. 



and with a proper apparatus it should be possible to show the 

 individual contractions of which the complete movement is 

 composed. In fact a similar apparatus is being used to 

 analyse various sorts of tremors in patients. 



Models more like the cochlea have been made, but they 

 are not so convenient for purposes of demonstration. 



Phil. Mag. S. 6. Vol. 43. No. 254. Feb. 1922. 2 A 



i 



