152 rSYCIIOLOGY. 



the rapidity of the blows, tho tone undergoes the change of quality dis- 

 tinguished as rise in pitch ; and it continues to rise in pitch as tlie blows 

 continue to increase in rapidity, until it readies an acuteness beyond 

 which it is no longer appreciable as a tone. So that out of units of feel- 

 ing of the same kind, many feelings distinguishable from one another 

 in quality result, according as the units are more or less integrated. 



•' This is not all. The inquiries of Professor Helmholtz have shown 

 that when, along with one series of these rapidly-recurring noises, there 

 is generated another series in which the noises are more rapid though 

 not so loud, the effect is a change in that quality known as its timbre. 

 As various musical instruments show us, tones which are alike in pitch 

 and strength are distinguishable by their harshness or sweetness, their 

 ringing or their liquid characters; and all their specific peculiarities are 

 proved to arise from the combination of one, two, three, or more, sup- 

 plementary series of recurrent noises with the chief series of recurrent 

 noises. So that while the unlikenesses of feeling known as differences 

 of pitch in tones are due to differences of integration among the recur- 

 rent noises of one series, the unlikenesses of feeling known as differ- 

 ences of timbre, are due to the simultaneous integration with this series 

 of other series having other degrees of integration. And thus an 

 enormous number of qualitatively-contrasted kinds of consciousness 

 that seem severally elementary prove to be composed of one simple 

 kind of consciousness, combined and recombined with itself in multi- 

 tudinous ways. 



"Can we stop short here? If the different sensations known as 

 sounds are built out of a common unit, is it not to be rationally inferred 

 that so likewise are the different sensations known as tastes, and the 

 different sensations known as odors, and the different sensations known 

 as colors ? Nay, shall we not regard it as probable that there is a unit 

 common to all these strongly-contrasted classes of sensations ? If the 

 unlikenesses among the sensations of each class may be due to unlike- 

 nesses among the modes of aggregation of a unit of consciousness com- 

 mon to them all-; so too may the much greater unlikenesses between 

 the sensations of each class and those of other classes. There may be a 

 single primordial element of consciousness, and the countless kinds of 

 consciousness may be produced by the compounding of this element 

 with itself and the recompounding of its compounds with one another 

 in higher and higher degrees : so pi'oducing increased multiplicity, 

 variety, and complexity. 



"Have we any clue to this primordial element ? I think we have. 

 That simple mental impression which proves to be the unit of composi- 

 tion of the sensation of musical tone, is allied to certain other simple 

 mental impressions differently originated. The subjective effect pro- 

 duced by a crack or noise that has no appreciable duration is little 

 olse than a nervous shock. Though we distinguish such a nervous 

 shock as belonging to what we call sounds, yet it docs not differ very 

 much from nervous shocks of other kinds. An electric discharge sent 



