vi PREFACE 



was to assert the claims of one of what may be 

 called the " pre-efficients " 1 of eminent men, the 

 importance of which had been previously over- 

 looked ; and I had yet to work out more fully 

 its relative efficacy, as compared with those of 

 education, tradition, fortune, opportunity, and 

 much else. It was therefore with no ordinary 

 interest that I studied M. de Candolle's work, 

 finding in it many new ideas and much con- 

 firmation of my own opinions ; also not a little 

 criticism (supported, as I conceive, by 'very im- 

 perfect biographical evidence,) 2 of my published 

 views on heredity. I thought it best to test 

 the value of this dissent at once, by limiting 

 my first publication to the same field as that on 

 which M. de Candolle had worked namely, to 

 the history of men of science, and to investigate 

 their sociology from wholly new, ample, and 

 trustworthy materials. This I have done in 

 the present volume ; and I am confident that 



1 Or, " all that has gone to the making of." The word 

 was suggested to me. 



Reference may be made to a short review by me of M. 

 de Candolle's work, in the Fortnightly Review, March 1873. 



