48 FRAGMENTS OF SCIENCE 



up. A single experiment is frequently devised, by which 

 the theory must stand or fall. .Of this character was the 

 determination of the velocity of light in liquids, as a 

 crucial test of the Emission Theory. According to it, 

 light travelled faster in water than in air; according to 

 the Undulatory Theory, it travelled faster in air than in 

 water. An experiment suggested by Arago, and exe- 

 cuted by Fizeau and Foucault, was conclusive against 

 Newton's theory. 



But while science cheerfully submits to this ordeal, it 

 seems impossible to devise a mode of verification of their 

 theories which does not rouse resentment in theological 

 minds. Is it that, while the pleasure of the scientific 

 man culminates in the demonstrated harmony between 

 theory and fact, the highest pleasure of the religious 

 man has been already tasted in the very act of pray- 

 ing, prior to verification, any further effort in this direc- 

 tion being a mere disturbance of his peace ? Or is it that 

 we have before us a residue of that mysticism of the 

 Middle Ages, so admirably described by Whewell that 

 "practice of referring things and events not to clear and 

 distinct notions, not to general rules capable of direct 

 verification, but to notions vague, distant, and vast, 

 which we cannot bring into contact with facts; as when 

 we connect natural events with moral and historic 

 causes?" "Thus," he continues, "the character of mys- 

 ticism is that it refers particulars, not to generalizations, 

 homogeneous and immediate, but to such as are hetero- 

 geneous and remote; to which we must add that the 

 process of this reference is not a calm act of the intel- 

 lect, but is accompanied with a glow of enthusiastic 

 feeling." 



