547 



SCIENTIFIC SIDE-LIGHTS 



Power 

 Prayer 



duced to a rudimentary state. There are 

 fishes also which have had to pay the same 

 terrible forfeit for having made their abode 

 in dark caverns, where eyes can never be 

 required. And in exactly the same way the 

 spiritual eye must die and lose its power by 

 purely natural law if the soul choose to 

 walk in darkness rather than in light. 

 DRUMMOND Natural Law in the Spiritual 

 World, essay 2, p. 99. (H. Al.) 



2697. PRACTISE, EFFECT OF Ma- 

 chine Runs More Easily by Use Exertion 

 Secures Increased Supply Nerve Stimula- 

 tion More Readily Set Up. A movement 

 which takes place again and again in the 

 same direction comes by degrees to follow 

 this direction more readily than any other, 

 and will presently be unaffected by influ- 

 ences which at first would have had no dif- 

 ficulty in diverting it. When water is 

 poured upon the ground it forms a channel 

 for itself. Its initial direction may have 

 been determined by the merest accident, but, 

 once determined, is adhered to, and the more 

 certainly the oftener we pour. When a ma- 

 chine is set in motion there is always the 

 same resistance of mass to be overcome in 

 its various parts; but friction is lessened 

 by the wearing and smoothing of part 

 against part, so that a machine which has 

 been going for some time usually runs more 

 easily than a new one or cne which has lain 

 for a long time unused. If you let your 

 watch run down, and do not wind it up for 

 a fortnight, you know that it is always 

 liable to stop until it has been going again 

 for a week or so. Now there is good evi- 

 dence for the view that the same thing holds 

 of neural processes. If we are in the habit 

 of executing some definite muscular move- 

 ment we know that it gradually becomes 

 easier t. e., can be made with less expendi- 

 ture of force. What we call " practise " 

 consists simply in changes of this sort. The 

 execution of a practised movement becomes 

 easier because the stimulation-process in 

 nerve and muscle is the more easily set up 

 the more frequently it is repeated. This 

 process is originated by an increased sup- 

 ply of the elements essential to the tissues; 

 so that exercised muscles show an increase 

 in the mass of their contractile substance. 

 WUNDT Psychology, lect. 9, p. 144. (Son. 

 & Co., 1896.) 



2698. PRACTISE MUST BE SUP- 

 PORTED BY THEORY Closet Workers Need- 

 ful to Sustain Industrial Achievement. To 

 keep society as regards science in healthy 

 play, three classes of workers are necessary : 

 Firstly, the investigator of natural truth, 

 whose vocation it is to pursue that truth, 

 and extend the field of discovery for the 

 truth's own sake, and without reference to 

 practical ends. Secondly, the teacher of 

 natural truth, whose vocation it is to give 

 public diffusion to the knowledge already 

 won by the discoverer. Thirdly, the applier 

 of natural truth, whose vocation it is to 



make scientific knowledge available for the 

 needs, comforts, and luxuries of civilized 

 life. These three classes ought to coexist 

 and interact. Now, the popular notion of 

 science, both in this country and in Eng- 

 land, often relates not to science strictly 

 so called, but to the applications of science. 

 Such applications, especially on this conti- 

 nent, are so astounding they spread them- 

 selves so largely and umbrageously before 

 the public eye that they often shut out 

 from view those workers who are engaged 

 in the quieter and profounder business of 

 original investigation. TYNDALL Lectures 

 on Light, lect. 6, p. 219. (A., 1898.) 



2699. PRACTISE TRANSFORMS 

 VOLUNTARY INTO AUTOMATIC MOVE- 

 MENT Practise always implies that an 

 action which at first was performed volun- 

 tarily has gradually become reflex and au- 

 tomatic. Thus when the child learns to 

 walk, the taking of each single step is ac- 

 companied by. a considerable effort of will; 

 but after a time and by slow degrees it be- 

 comes able to initiate a whole series of move- 

 ments without attending to their execution 

 in detail. In the same way we learn to 

 play the pianoforte or to execute other com- 

 plicated movements of the hands by frequent 

 repetition of particular and connected acts, 

 and their consequent transformation into a 

 chain of effects which follow each other 

 with mechanical certainty when once the 

 appropriate impulse has been given. Now 

 the modifications which the nervous system 

 undergoes during the life of the individual, 

 in consequence of the mechanizing of these 

 practised movements, must naturally, like 

 all other modifications of the same kind, 

 be summated and intensified in the course 

 of generations. The purposive character of 

 the reflexes becomes then readily intelligible, 

 if we regard them as resulting from the 

 voluntary action of previous generations. 

 WUNDT Psychology, lect. 15, p. 227. (Son. 

 & Co., 1896.) 



2 7 GO. PRAYER A UNIVERSAL IM- 

 PULSE Will Persist Spite of All Discussion. 

 We hear, in these days of scientific en- 

 lightenment, a great deal of discussion about 

 the efficacy of prayer; and many reasons 

 are given us why we should not pray, whilst 

 others are given us why we should. But 

 in all this very little is- said of the reason 

 why we do pray, which is simply that we 

 cannot help praying. It seems probable that, 

 in spite of all that " science " may do to 

 the contrary, men will continue to pray to 

 the end of time, unless their mental nature 

 changes in a manner which nothing we know 

 should lead us to expect. The impulse to 

 pray is a necessary consequence of the fact 

 that whilst the innermost of the empirical 

 selves of a man is a self of the social sort, 

 it yet can find its only adequate socius in 

 an ideal world. JAMES Psychology, vol. i, 

 ch. 10, p. 316. (H. H. & Co., 1899.) 



