2 Trans. Acad. Sci. of St. Ltniis 



iHidorstood. Tho activating atxcrit wliicli is to Itc traiis- 

 forrod to tli<' ncrv(» endiii.LC in tt-rnis of inijnilsc, 

 must ))(' applied directly t<> flic nerve ending 

 or to the cells which overlie the nerve ending. 

 This stat(>nient holds for the sensations of touch, of 

 pressure, of smell and of taste. We also recognize 

 that heat is transmitted llirou^h various substances 

 which may intervene between iho source of the 

 energy and the part which j)erceives the sensation. 

 Therefore when tlie end or^an is affected by the energy 

 which arises from the object rather than by the object 

 itself, we are dealinf2: with distance rather than contact 

 organs. The end or^an resolves the energy, not the ob- 

 ject, in terms of code messaji^e. We do not see heat; we 

 feel it. We do not feel lii^ht rays; we see them. It 

 would therefore follow as a matter of fi^ood loi^nc, that 

 we do not see or feel energy in the form of sound; we 

 hear it. 



Sound, next to heat, is the most dillieiiH form of eniM'- 

 gy to deal with satisfactorily. From an experimental 

 point of view it is the most dillicult form of ejierjjjy to 

 analyze. The reason for this is easily <^rasped. In so far 

 as sense organs are concerned, they are crude physical 

 instruments when compared with the scales for measur- 

 ing: pressur(\ the thermometer for measuring tempera- 

 ture, or the photographic plate for measurin;^: li^''ht. 

 However when it comes to sound the reverse is true. 

 All physical instruments for registering sound are ex- 

 tremely crude when compared with the Innnan ear. In 

 fact no instrumiMit for measuring sound has yet been 

 devised which does not have a human ear on one end of 

 it. The ])honodeik of Miller i>resents an instrument of 

 great di^licacy but with a limited range of registration. 



We are likely to visualize tlie w<irking of an ear much 

 in the same nuinner as we visualize the operation of an 

 eye by comparing it with some well-known i)hysical ap- 

 paratus. Bearing in mind the reservations in the pre- 



