PHILOSOPHIC ANTS 189 



are distinguishable and pulse through us, and the 

 more the vibrations are separable, the more they are 

 felt as mechanical shocks, the less as sound. How- 

 ever, we know perfectly well that all sounds as a mat- 

 ter of fact depend on vibratory disturbance, and that 

 it is only some peculiarity of the registering ma- 

 chinery, in ear or brain, which enables us to hear a 

 note as continuous. 



Still more remarkable are the facts of vision. As 

 I write I see the tulips in my garden, red against the 

 green grass: the red is a continuous sensation; but 

 the physicists appear to be justified in telling us that 

 the eye is being bombarded every second with a series 

 of waves, not the few hundred or thousand that give 

 us sound, but the half-billion or so which conspire to 

 illuminate our vision. 



With sound, we alter the frequency of the waves 

 and we get a difference of tone which seems to be 

 merely a difference of more or less : but alter the fre- 

 quency of light-waves, and the whole quality of the 

 sensation changes, as when I look from the tulips to 

 the sky. The change of registering mechanism is 

 here more profound than the change in outer event. 



Or again, to choose an example that depends more 

 on size than rhythm, how very, difficult it is to re- 

 member that the pressure of air on our bodies is not 

 the uniform gentle embrace of some homogeneous 

 substance, but the bombardment of an infinity of 

 particles. The particles are not even all alike: some 

 are of oxygen^ others of nitrogen, of carbonic acid 



