PREFACE Vil 



are distributed among the sciences as follows : Chemistry, 175 ; physics, 150 ; zoology, 

 150 ; botany, 100 ; geology, 100 ; mathematics, 80 ; pathology, 60 ; astronomy, 50 ; 

 psychology, 50 ; physiology, 40 ; anatomy, 25 ; anthropology, 20. The star means that 

 the subject of the biographical sketch is probably among the leading thousand students 

 of science of the United States ; but its absence does not necessarily mean that the sub- 

 ject of the sketch does not belong in this group, as the name may not have been con- 

 sidered in making the arrangements. 



My object in determining the thousand leading American men of science was to se- 

 cure a group for scientific study. I have also selected for this purpose the thousand lead- 

 ing men in the history of the world arranged in the order of eminence, and I am select- 

 ing a thousand students of Columbia University. My original interest in this work of 

 reference was to secure data for a statistical study of the conditions, performance, traits, 

 etc. , of a large group of men of science, and I had intended to include the results of this 

 study in the book. It seems, however, unwise to postpone the publication of the bio- 

 graphical sketches until the scientific study has been completed.* 



I am under unusual obligations to a large number of men of science for assistance in 

 this work. I should be glad to give a list of about two hundred to whom I am partic- 

 ularly indebted, but perhaps some of them would prefer not to have their names men- 

 tioned. I have been assisted in the compilation by Mr. Wm. Harper Davis, then assist- 

 ant in psychology at Columbia University and now assistant professor in Lehigh Uni- 

 versity, by Dr. H. D. Marsh, then scholar in psychology at Columbia University and 

 now instructor in Ohio Wesleyan University, by Miss M. C Ennis, and most of all by 

 Dr. Vivian A. C. Henmon, now lecturer in psychology at Columbia University. So 

 much completeness and accuracy as the w T ork may have is largely due to them. 



J. McKeen Cattell 

 Columbia Univeesity, 

 January, 1906 



* Two papers on the subject have been printed ' Homo Scientificus Americanus : Address of the presi- 

 dent of the American Society of Naturalists,' Science, N. S., 17 : 561-570, 1903, and 'Statistics of Ameri- 

 can Psychologists,' Am. Jour, of Psychol., 14 : 310-328, 1903. A further series of articles, which is now 

 nearly ready, will probably be printed in Science. Cf. in regard to the other groups ' A Statistical Study of 

 Eminent Men,' Pop. Sci. Mon., 53 : 359-378, 1903, and ' Physical and Mental Measurements of the Students 

 of Columbia University,' Psychol. Rev., : 618-648, 1896. 



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-UJ LIBRARY S 





