440 THE POPULAR SCIENCE MONTHLY. 



ment of the finger is the movement thovg/tt of, and in the second 

 place because its movement and that of the key are the movements 

 we try to perceive, along with the results of the latter on the ear. The 

 more often the process is repeated, the easier the movement follows, on 

 account of the increase in permeability of the nerves engaged. 



" But the more easily the movement occurs, the slighter is the 

 stimulus required to set it up ; and the slighter the stimulus is, the 

 more its effect is confined to the fingers alone. 



" Thus, an impulse which originally spread its effects over the 

 whole body, or at least over many of its movable parts, is gradually 

 determined to a single definite organ, in which it effects the contrac- 

 tion of a few limited muscles. In this change the thoughts and per- 

 ceptions which start the impulse acquire more and more intimate 

 causal relations with a particular group of motor nerves. 



"To recur to a simile, at least partially apt, imagine the nervous 

 system to represent a drainage-system, inclining, on the whole, toward 

 certain muscles, but with the escape thither somewhat clogged. Then 

 streams of water will, on the whole, tend most to fill the drains that 

 go toward these muscles and to wash out the escape. In case of a 

 sudden 'flushing,' however, the whole system of channels will fill it- 

 self, and the water overflow everywhere before it escapes. But a 

 moderate quantity of water invading the system will flow through 

 the proper escape alone. 



"Just so with the piano-player. As soon as his impulse, which has 

 gradually learned to confine itself to single muscles, grows extreme, 

 it overflows into larger muscular regions. He usually plays with his 

 fingers, his body being at rest. But no sooner does he get excited 

 than his whole body becomes ' animated,' and he moves his head and 

 trunk, in particular, as if these also were organs with which he meant 

 to belabor the keys." * 



Man is born with a tendency to do more things than he has ready- 

 made arrangements for in his nerve-centers. Most of the perform- 

 ances of other animals are automatic. In him, most of them must be 

 the fruit of painful study. If practice did not make perfect, nor habit 

 economize the expense of nervous and muscular energy, he would 

 therefore be in a sorry plight. As Dr. Maudsley say»,f "If an act 

 became no easier after being done several times, if the careful direc- 

 tion of consciousness were necessary to its accomplishment on each 

 occasion, it is evident that the whole activity of a lifetime might be 

 confined to one or two deeds — that no progress could take place in 

 development. A man might be occupied all day in dressing and un- 

 dressing himself ; the attitude of his body would absorb all his atten- 

 tion and energy ; the washing of his hands or the fastening of a button 



* G. II. Schneider, "Dcr menschliche Willc," 1882, pp. 417-410 (freely translated). 

 For the drain-simile, cf. Spencer's " Psychology," Part V, chap. viii. 

 f "Physiology of Mind," p. 155. 



