480 THE INTELLECTUAL RISE IN ELECTRICITY. 



is still more curious, the very ones, the metals, which it 

 was most difficult or apparently impossible to charge 

 simply by rubbing them, now receive more electricity than 

 "" all others on mere approximation of the excited tube. 

 Here are two capital discoveries made at the very thres- 

 hold of his labor. 



This is not altogether unusual, as many a later investi- 

 gator can testify. Long study and thought produces a 

 sort of mental polarization that somehow dulls the percept- 

 ive faculties, or results in an intellectual inertia which 

 renders it difficult for the mind to turn itself out of the 

 path in which it has been moving. And, as a consequence, 

 the power of original thought, of invention, is apt to 

 weaken even in those most highly gifted with creative 

 genius, unless the brain-work be differently directed for a 

 time, or wholly intermitted for a period of rest. There 

 seems to be no exhaustion of energy, for the thinking 

 mechanism may continue its operation, although fruit- 

 lessly, with even greater assiduity than ever. It is rather 

 a new condition of the apparatus which causes a change 

 in the quality of its accomplishment. Therefore when a 

 new mind not polarized attacks the problem, it is very 

 apt not only to perceive solutions which evade the recog- 

 nition 'of those which have long grappled with it, but to 

 see the most prominent and general ones first. It is an in- 

 cident of progress, and apparently a necessary one, that 

 obstacles shall be attacked by a succession of new minds; 

 and it constantly happens that a new mind without exper- 

 ience is often more potent in overcoming them than one 

 rich with accumulated knowledge. 



Gray had almost instantly discovered that electricity 

 would pass from the excited body to one not excited: from 

 the glass tube to the cork. Dufay also at once finds all 

 bodies capable of electrification. Gray was halted by doubts 

 as to the effect of the physical conditions of the body to which 

 the charge is communicated. So Dufay similarly pauses be- 

 cause of misgivings as to the influence of color these not 



