8 ENGLISH MEN OF SCIENCE. [CHAP. 



tions of Darwin. In spectrum analysis the re- 

 marks of Stokes were anterior to and independ- 

 ent of the works of Kirch'hoff and Bunsen. Elec- 

 tric telegraphy has numerous parents, German, 

 English and American. The idea of conserva- 

 tion of energy has unnumbered roots. The sim- 

 ultaneous discovery of the planet Neptune on 

 theoretical grounds by Leverrier and Adams 

 is a very curious instance of what we are con- 

 sidering. In patent inventions the fact of 

 simultaneous discovery is notoriously - frequent. 

 It would therefore appear that few discoveries 

 are wholly due to a single man, but rather 

 that vague and imperfect ideas, which float 

 in conversation and literature, must grow, 

 gather, and develop, until some more perspi- 

 cacious and prompt mind than the rest clearly 

 sees them. Thus, Laplace is understood to 

 have seized on Kant's nebular hypothesis and 

 Bentham on Priestley's phrase, " the greatest 

 happiness of the greatest number," and each 

 of them elaborated the idea he had so seized, 

 into a system. 



The first discoverers beat their contemporaries 



