THE QUEST OF NITROGEN 113 



the matter finally was given the world. These men were 

 wide observers : they included the field, as well as the 

 laboratory, the fertile soil and the infertile soil, summer 

 crops and winter crops ; they sought the truth, and would 

 not be comforted so long as a single doubt remained. For 

 did not every field trial show that the legume produced 



A MAGNIFICENT CROP OF BEANS 



Legumes subsoil the land, contribute to the humus stores and add nitrogen to 



the soil 



abundantly, although in these same soils the cereal pro- 

 duced indifferently? Was it not true that in every case 

 where a legume occupied the land for a few years, when 

 succeeded by a cereal, a marked increase was apparent 

 over similar soil, unoccupied previously by some crop not 

 a legume? So spoke Yoelcher with conviction: the 



