252 



SCIENCE 



[N. S. Vol. XL VI. No. 1185 



all great problems, particularly those of 

 our national and state governments, will 

 be automatically placed in the hands of 

 trained specialists? Not self-seeking poli- 

 ticians, nor yet men with mere theories, but 

 engineers with a real command of funda- 

 mental principles, men with an unbroken 

 record of big achievements and no failures, 

 men ever ready to stake their all on their 

 ability to handle problems in their spe- 

 cialty. 



Professor Joseph Le Conte, in an ad- 

 dress years ago, remarked that each of the 

 great professions first attained high stand- 

 ing when it was taught as such in universi- 

 ties. When so taught, the professional 

 men turned out are no longer quacks, but 

 each has a real command of the funda- 

 mental principles in his chosen field of 

 action. The basic relation is that any pro- 

 fession has standing in so far as its funda- 

 mental principles have been developed and 

 applied. To retain standing, a profession 

 must be continually increasing its stock of 

 knowledge of fundamental principles 

 through research. The engineer of stand- 

 ing in his profession must not be content 

 with a mere working knowledge of rules of 

 thumb, but must have a real command of 

 basic principles in his chosen field and in 

 related fields. The illuminating engineer, 

 for example, should know not only lighting, 

 but should possess a working knowledge of 

 the laws of vision and of geometrical and 

 physical optics. So the great physician or 

 construction engineer has a command of 

 his own field and an intimate acquaintance 

 with related fields. 



So also with research as a profession, the 

 leaders have not only a taste for research 

 and logical minds to clearly analyze and 

 attack problems with thorough scientific 

 knowledge, but have a knowledge of the 

 principles of research ; getting the most out 

 of their own minds, avoiding side issues, 



cooperating with their colleageus and put- 

 ting their most valuable results in perma- 

 nent, readily available form. Research is 

 one of the youngest of the professions and 

 one with a promising future, but let no 

 one enter it without thorough knowledge 

 or a full understanding of its aims and 

 methods. With sufficient attention given 

 to research and to its application, this na- 

 tion with its great national resources 

 should at once attain and retain a perma- 

 nent lead among the nations of the earth. 

 P. G. Nutting 



THE PROOF OF MICROBIAL AGENCY 

 IN THE CHEMICAL TRANSFORMA- 

 TIONS OF SOIL 



Every now and then in the development of 

 a science it is well to stop and consider how 

 many of the current statements are based on 

 established fact and how many have arisen from 

 assumptions repeated so often that they have 

 come to be generally believed. Certain com- 

 mon statements in regard to the bacteriology 

 of soil may well bear such scrutiny. Has it, 

 for instance, been definitely proved that any 

 particular microorganisms cause any of the 

 well-known biological activities in soil? This 

 question is quite pertinent at present because 

 of statements frequently found in the liter- 

 ature that certain bacteria or groups of bac- 

 teria are responsible for certain chemical 

 transformations in soil, although complete 

 proof of the causal relation has never been 

 obtained. 



The cause of these loose statements is easy 

 to understand when it is considered that it is 

 practically impossible to obtain direct evi- 

 dence as to what actually goes on within the 

 soil. Laboratory experiments show what the 

 microorganisms do under laboratory condi- 

 tions, but not what they do in the soil. Even 

 though the activity of an organism be tested 

 in soil itself, its true activity in the field may 

 still remain unknown, because such laboratory 

 tests have to be carried out in pure culture, 

 and pure cultures do not occur in the field. 

 The activities of bacteria in soil are associ- 



