THE COMPOSITION OF MIND 



of undulatory movements by which myriads of 

 molecules are seeking to reach a position of 

 equilibrium. Accordingly, the end of the nerve 

 fibrils in the olfactory chamber or in the tongue 

 must be rapidly smitten by little molecular 

 waves, just as the auditory filaments are smitten 

 by atmospheric waves ; and thus there is indi- 

 cated a course of argument similar to that em- 

 ployed in the case of sound. It may be fairly 

 argued that if each wave does not produce some 

 sub-conscious psychical effect, the sum of the 

 waves will not produce a state of consciousness 

 known as smell or taste ; so that here too the 

 seemingly primitive sensation is really deriva- 

 tive and compound. 



M. Taine*s argument with reference to the 

 tactile sensations is singularly beautiful, but no 

 room is left for more than the briefest allusion 

 to a few of its salient points. All tactile sensa- 

 tions are either dermal or muscular ; that is, they 

 are due either to disturbances of nerve fibrils 

 embedded in the skin, or to disturbances of 

 nerve fibrils embedded in the extremities of the 

 muscles lying under the skin. In the first case, 

 the sensation is either of contact or of tempera- 

 ture ; in the second case, there is a sensation of 

 resistance or pressure ; and in both cases, when 

 the sensation proper to the nerve is prolonged 

 or intensified beyond a certain degree, it is at 

 first accompanied and finally supplanted by a 



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