322 TEANSACTIONS LIVEEPOOL BIOLOGICAL SOCIETY. 



III., pt. iii, p. 127) are in millimetres and not in micro- 

 millimetres as there stated. 



The aim of my investigation has been, not to find an 

 explanation of the sensation of sound, at least not in the 

 first instance, but merely to lay a solid foundation for 

 future explanations by considering the physical changes 

 produced in the ear by the impact of- sound waves upon 

 the tympanic membrane. 



From this point of view it is equally important to follow 

 out to the end the whole chain of effects in the case of 

 every part, however little may seem the probability of 

 finding in them a solution of the physiological problem 

 of hearing : the problem to be attacked is indeed in the 

 first instance not a physiological one at all, but one in 

 pure physics, and as such it must be treated ; leaving 

 altogether out of account any and every physiological 

 consequence which may follow, and carefully avoiding all 

 those suggestive analogies with musical instruments 

 which have led previous investigators into erroneous 

 assumptions as to " functions " of one part or another. 

 Each part must be considered, in the first instance, as an 

 inert body whose properties are to be determined only 

 by observation and not assumed beforehand on the 

 strength of any preconceived notion as to the way in 

 which they " must " act in order to produce certain effects. 



For this reason the first portion of the theory is 

 addressed to physicists rather than to physiologists and 

 to the latter only is so far as they are physicists as well 

 as physiologists. 



The Physical Effects oe Changes pboduced in the 



Middle Eae by the Impact of Sound Waves 



on the Tympanic Membeane. 



The movement of the membrane, due to changes of 



