HISTORY OF SOIL MICROBIOLOGY 837 



as contributing to the advance of soil microbiology. Any discovery 

 in the field of chemistry or physics, which has a bearing upon soil 

 formation, composition and processes, upon the chemistry of plant 

 cells, as well as any new methods of analysis, are of direct importance 

 to the development of soil microbiology. 



It is argued, however ( Winogradsky) , that, while a great deal of 

 information has accumulated on the methods of isolation and culti- 

 vation of certain organisms present in the soil, while a great many 

 organisms have been isolated and described, while the biochemical 

 activities of a number of these organisms are known, there is still lacking 

 the science of soil microbiology proper, or the applied science. 



The beginnings of soil microbiology as an independent science date 

 back to the sixth and seventh decades of the last century. There are 

 two outstanding names in soil chemistry and bacteriology, whose 

 theories were far from agreeing, but whose researches have dovetailed 

 to give origin to the science; namely, those of Liebig (1840) and 

 Pasteur (1860). Liebig 's theories of soil fertility fell short because he 

 did not recognize the activities of microorganisms. Pasteur's work 

 was not concerned directly with soil microorganisms, but his bacterio- 

 logical investigations in general, and specifically the study of the 

 various fermentations including that of urea and butyric acid, pointed 

 the way to a new development. 



It remained for the practical agriculturist to combine the efforts 

 of the chemist and bacteriologist and call attention to the importance 

 of microorganisms in soil fertility. Kette 3 (1865) deserves the credit 

 for being the first to recognize this fact. He advanced the fermenta- 

 tion theory, in which he stated that the importance of the addition of 

 stable manure to the soil consisted in the fact that it cannot be replaced 

 by nitrogen compounds and minerals as well as by purely vegetable 

 matter, because the latter lack "a true vibrion fermentation." His 

 views have found ardent adherents, as can be recognized from the work 

 of Rosenberg-Lipinsky, 4 who stated that "milliards of lower animals 

 per acre are born every moment and die after a few days, sometimes 

 after a few hours, serving others as food." The birth, or rather 

 awakening, of medical bacteriology in the early part of the ninth decade 

 of last century was also accompanied by a rapid development in soil 

 bacteriology. The work of Koch on the gelatin plate method, of 



3 Kette, W. Die Fermcntationstheorie gegenuber der Humus-Mineral und 

 Stickstofftheorie. 2 Aufl. 1865. 



4 Rosenberg-Lipinsky. Der praktische Ackerbau. 3 Aufl., 2: 27. 1S69. 



