258 



SCIENCE 



[N. S Vol. XLII. No. 1078 



greater extent than the domain of agri- 

 culture. 



The applications of fermentations may 

 be followed into the management of the 

 soil, the plants which grow therefrom, and 

 the animals which in turn are fed by them. 

 Microorganisms are the initial agents which 

 work through their dynamic forces and 

 contribute the results of their energy to 

 the cause of agriculture and man. More 

 particularly these activities manifest them- 

 selves in the upkeep of the soil or in soil 

 fertility with its complications of ele- 

 mental reactions, in the growth and dis- 

 eases of plants, in the nutritional and 

 pathological processes of animals, in the 

 canning, drjdng, refrigerating, brining and 

 spoliation of food, in the production of 

 wine, beer, bread and vinegar, in the care 

 of water supplies, in sewage disposal, in the 

 manufacture of vaccines and serum prod- 

 ucts, in public health control, all of which 

 make the profession of agriculture more 

 definite and more scientific. 



It is peculiarly fitting to assign to Liebig 

 the synthetic initiative in scientific agricul- 

 ture, for through him agricultural knowl- 

 edge was first effectively arranged or syste- 

 matized, brought out of ignorant obscurity, 

 and placed in line for further and secure 

 development. Although he failed to grasp 

 the full significance of the true role of 

 microorganisms in nature, he nevertheless 

 provided the encompassing and essential 

 knowledge which enabled microbiology to 

 find the basis upon which to build its 

 superstructure. In other words, he ex- 

 cavated and placed the stone with the 

 cement, but it was left to Pasteur to pre- 

 pare the framework of the biological build- 

 ing to be placed upon this foundation. Re- 

 verting to the forces which focused in 

 Pasteur, Liebig was probably more success- 

 ful in converging them than any other 

 scientific investigator. 



It is especially easy to trace to Liebig 's 

 soil studies those pioneer observations bear- 

 ing on the formation of such compounds as 

 am m onia, and nitrates in the soil, and such 

 other facts as point the way to a utiUzable 

 knowledge of scientific agriculture. He 

 recognized the accumulation of nitrogen in 

 the soil, but failed to conceive, before his 

 death, the nature of the process concerned 

 with its accumulation, whether, as we 

 now view it, symbiotic or nonsymbiotic. 

 In advancing the theory that ammonia 

 was washed from the air by the rain, 

 he did not receive general support because 

 it was only a small fraction of the truth. 

 There was lacking apparently a link in 

 the chain of needed evidence. He wandered 

 into the present overwhelming subjects of 

 plant and animal physiology without fully 

 appreciating the labyrinth of scientific 

 dangers and difficulties he was likely to en- 

 counter, but he extricated himself with 

 wonderful tact after surveying thoroughly 

 the entrance chambers and the bearings of 

 the leads into the unknown. No one may 

 have brought to light so many experi- 

 mental data, demonstrated so many isolated 

 agricultural activities as had Liebig, but 

 they were unbounded, to a degree unre- 

 lated, and could not be carried fully and 

 successfully to application largely because 

 they lacked the vehicle of a consistent or 

 logical directive principle. In Liebig 's 

 day no guiding hand led the way and this 

 wilderness of observation remained dense 

 and impenetrable, for causes and their con- 

 sequences must include the processes in- 

 volved, and all must be determined before 

 true, intelligent and continuous progress 

 can be made. 



Pasteur, by an almost intuitive insight 

 into the operations of nature, was the first 

 who could with some authority suggest the 

 possibility that nitrification may be insti- 

 gated by microorganisms. This was later 



