CORRESPONDENCE 107 



understanding of our views with regard to impulses and analy- 

 sis. With regard to the former he does not allude to the 

 effect of the initial and varying elastic resistances caused in 

 the basilar membrane, the ossicular muscles, the bending hair- 

 lets, the stalk of the tectorius, etc., all of which oppose the 

 pressures of the air-wave in accordance with Hooke's law. In 

 our book all this is investigated. It is also pointed out that 

 by the mechanism of the cochlea, the sine curve in air at its 

 position of highest amplitude where the change of pressure is 

 most gradual, is by these resistances entirely altered in form. 



In the sense of so altering the wave-form when it arrives 

 in the liquid that the four impulses become equally definite, 

 the cochlea may be regarded as having an analytic power and 

 creates or makes accurately definite, certain impulses which 

 are subjective and formed in the cochlea and cannot therefore 

 be detected by resonators acting in the air. 



Professor Barton next draws attention to our conclusions, 

 " That because liquids are incompressible the liquids present 

 in the cochlea must move in a piece and affect all the graduated 

 mechanism equally and simultaneously," and asks what is 

 there to prevent the various parts of this mechanism, and 

 those only, responding which are in tune with the pressure 

 wave arriving." This may appear simple when one tone alone 

 is sounding, but the ear can detect many such tones sounding 

 together. 



Under such conditions where does the Professor's hypo- 

 thesis for improving our theory land him ? 



With a number of notes sounding together, the strings of 

 the basilar membrane would move with different vibration 

 rates in the different positions of the membrane, and therefore 

 in constantly differing directions. What becomes of the dis- 

 placement ? and how are we to explain that, while some of the 

 strings are moving in one direction, due to the pressure of the 

 liquid, other strings should move in the opposite direction to 

 the pressure, which, according to the hypothesis, causes their 

 movement ? 



Further, what happens when the anatomists have demon- 

 strated that all these so-called resonators are not free to move 

 independently, but are cemented laterally together? 



Again, Resonance requires time to produce its effect. Mr. 

 Sedley Taylor found by experiment that, with two tuning-forks 



