698 THE century's great men in science. 



Of all men of the ceiituiT Faraday had the greatest power of draw- 

 ing ideas straight out of hi.s experiments and making his physical 

 apparatus do his thinking, so that experimentation and inference were 

 not two proceedings, but one. To understand what this means, read 

 his "Researches on Electricity." His genius was thus higher than 

 that of H(dmholtz, who fitted a phenomenon with an appropriate con- 

 ception out of his store, as one might tit a bottle with a stopper, llie 

 most wonderful capacit}' for "catching on" to the ideas of nature 

 when these were of a complicated kind was shown l)}^ Mendeleef in 

 making out the periodic law of the chemical elements, as one might 

 make out the meaning of a pantomime, from data so fragmentjiry, 

 and in some cases erroneous, that the interpretation involved the cor- 

 rection of sundr}'^ facts, corrections since confirmed, as well as the 

 prediction of the very peculiar properties of the unknown gallium, 

 scandium, and germanium, which were soon afterwards actually met 

 with. Minute examination of all his utterances convinces one that 

 Mendeleef's mental processes in this unparalleled induction were 

 largely subconscious and. as such, indicate an absorption of the man's 

 whole being in his devotion to the reason in facts. 



A great naturalist, as well as I can make out, is u man whose 

 capacious skull allows of his being on the alert to a hundred different 

 things at once, this same alertness being connected with a power of 

 seeing the relations between different complicated sets of phenomena 

 when they are presented in their entirety'. The eighteenth century 

 had its Linnams. whose greatness even I can detect as I tui"n over his 

 pages; its Huber. discovering through others' eyes what others could 

 not discern with their own; its Goethe, its Haller, its Hunter, and 

 mixed with practical greatness, its Pinel and its Jenner. Then, there 

 was Lavater, who showed how pure aesthetic estimation might be 

 turned to the discovery of truth — a man depreciated because logicians 

 and philodoxers can so much more easily detect his weakness than 

 discern his strength. The nineteenth century, with its great thinker, 

 Darwin; its Pasteur (great in chemistry as well as in biology, a man 

 who impressed me personally, and impresses me in his works, as much 

 as any l)ut two or three of the century); its Lamaroll, Weissmann, 

 Cuvier, Agassiz, von Baer,. Bichat, Johannes Miiller, Robert Brown, 

 and I know not whom besides, has certainly garnered a magnificent 

 harvest of great men from this field. 



Those sciences which study individual objects and seek to explain 

 them upon physical principles — astronomy, geology, etc., correspond- 

 ing to history and biography on the psychical side — demand the great- 

 est assemblage of different powers. Those who pursue them have 

 first to be mathematicians, physicists, chemists, naturalists, all at once, 

 and, after that, astronomers or geologists in addition. It is almost 

 beyond human power. In the eighteenth centurj" A. G. Werner broke 



