SCIENCE 



FRffiAY, July 9, 1920 



CONTENTS 

 The Scientific Basis of the Illinois System of 

 Fermanent Soil Fertilitij : Professor Robert 

 Stewart 21 



Radicalism and Research in America: Dr. 

 Neil E. Stevens 25 



Scientific Events : — 



Biometric and Eugenic Laboratories at Uni- 

 versity College, London; Fisheries of the 

 Gulf States; Boad-huilding Projects with 

 Federal Aid; The Brewster Collection of 

 Birds; Hawaiian Scientific Institutions ... 30 



Uc Notes omd News 32 



University and Educational News 35 



Discussion and Correspondence : — 



Modern Interpretation of Differentials: 

 Pkopessok Arthur S. Hathaway. Note 

 on Distribution and Spermatogenesis of 

 Myriapoda: Dr. Horace Gunthorp 35 



Quotations : — 



The Endowment of Biochemical Research in 

 England 37 



Scientific Books: — 

 Abel's Die Stamme der Wirbelthiere: Dr. 

 W. D. Matthew 37 



Special Articles: — 

 An Ultramioroscopic Study of the Two 

 Stages of Blood Coagulation: Dr. Arnold 

 EiCE EiCH 38 



The Kentucky Academy, of Science: Dr. Al- 

 fred M. Petee 41 



MSS. intended for publication and books, etc., intended for 

 review ehould be sent to The Editor of Science, Garrison-oa- 

 Hudson, N. Y. 



THE SCIENTIFIC BASIS OF THE 



ILLINOIS SYSTEM OF PERMANENT 



SOIL FERTILITYi 



It is practically impossible to cover, in an 

 adequate way, the scientific principles underly- 

 ing the Illinois system of permanent soil fer- 

 tility in the brief space of time allotted me on 

 the program. ISTevertheless, I shall point out 

 the fundamental principles underlying the sys- 

 tem without attempting to illustrate the pioints 

 made by definite data as I should like to do. 



Eighty years ago Liebig, the father of agri- 

 cultural chemistry, made the following state- 

 ment: 



Agriculture is, of all industrial pursuits, the rich- 

 est in facts, and the poorest in their comprehen- 

 sion. Facts are like grains of sand which are 

 moved by the wind, but principles are these same 

 grains cemented into rocks. 



The greait contribution made to American 

 agriculture by the late Dr. Hopkins was the 

 gathering together, classifying, interpreting 

 and unifying, by his own investigations the 

 known facts of agriculture, into a definite 

 whole as practised and taught by him in the 

 Illinois system of permanent soil fertility. 



Many of the facts upon which the Illinois 

 system rests have been known for many years 

 and even centuries and have been developed by 

 other men in other institutions and in other 

 times. It remained, however, for Dr. Hopkins 

 to bring together and unify these isolated facts 

 into a definite workable system and by his ovsoi 

 investigation to demonstrate clearly that the 

 system could be understood and used by the 

 average farmer on his own farm with very 

 profitable results. In his interpretation of the 

 facts upon which the system is based, all men 

 have not agreed and some even still do not 

 agree with him but the system rests on the 



1 An address given at the Hopkins Memorial, 

 January 22, 1920 



