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used it in biology, an instrument which has 

 made science productive, and to which the 

 modern world owes its civilization. Our 

 every-day existence depends on the practi- 

 cal application of discoveries in pure sci- 

 ence by men who had no other motives than 

 a search for knowledge of Nature's laws, 

 a disinterestedness which Burnet claims to 

 be the distinctive gift of Hellas to humanity. 

 With the discovery of induced currents 

 Faraday had no thought of the dynamo. 

 Crookes's tubes were a plaything until 

 Roentgen turned them into practical use 

 with the X-rays. Perkin had no thought 

 of transforming chemical industry when 

 he discovered aniline dyes. Priestley would 

 have cursed the observation that an elec- 

 trical charge produced nitrous acid had he 

 foreseen that it would enable Germany to 

 prolong the war, but he would have blessed 

 the thought that it may make us independ- 

 ent of all outside sources for fertilizers. 



