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SCIENCE 



[N. S. Vol. XXXIII. No. 843 



that our first and most sacred duty is to 

 ascertain the facts in the life history of 

 microorganisms, to describe the laws gov- 

 erning them and to bring this knowledge 

 into bold relief, in order that so far as pos- 

 sible it may be utilized for the benefit of 

 humanity. 



It is often the tendency of men who 

 spend their lives in the seclusion of scien- 

 tific research to become less mindful of the 

 possible practical application of their work 

 than they are of the technical details and of 

 the truth which it reveals. This is of ne- 

 cessity a natural tendency, for application 

 can not go in advance of the discovery of 

 the facts to be applied. History is replete 

 with illustrations of unsuccessful efforts to 

 benefit humanity by applying theory or 

 dogma in the place of knowledge which 

 perhaps at the time did not exist. On the 

 other hand, the results of investigations of 

 the men of pure science have often led to 

 the formulation of exceedingly practical 

 procedures. In the development of the 

 theory and of the application of a science, 

 therefore, we have to deal with two factors, 

 namely, the intellectual longing for truth 

 regardless of its immediate significance, 

 and the desire to apply specific knowledge 

 for the benefit of society. Occasionally 

 these two elements are equally marked in 

 the same individual. As an example of a 

 mind dominated by the experimental 

 method, as well as the desire to alleviate 

 the suffering and to improve the life con- 

 ditions of mankind, there is no name that 

 can be mentioned with greater fitness than 

 that of Louis Pasteur, the founder of bac- 

 teriology as a practical science. 



Almost from its inception, bacteriology 

 has been a technical subject with important 

 practical applications. It has been the 

 agent that has revolutionized the medical 

 professions, vegetable pathology, dairying 

 and soil economics. The bacteriological 



work that is being done at the present time 

 is for the most part aimed directly at some 

 one or other of the problems in these prac- 

 tical fields. There are few sciences in 

 which the newly discovered facts or laws 

 have been so quickly utilized for some real 

 or hoped-for benefit to man or beast, as in 

 microbiology. The result of this haste to 

 apply new theories has tended to confuse 

 the public relative to the possibilities of a 

 knowledge of microorganisms. It is diffi- 

 cult to have the truth crystallized that 

 bacteriology is a technical subject which 

 can be understood by the specialist only. 

 The tendency to immediately apply newly 

 cited facts, before they are properly demon- 

 strated, has not infrequently permitted 

 errors to be proclaimed as truth, with 

 ultimate disappointment for both those 

 looking for beneficial results and those at- 

 tempting to attain them by the use of 

 methods based on somewhat hypothetical 

 data. 



This is illustrated by the present con- 

 fusion relative to the various groups of 

 bacteria. The discovery of the tubercle 

 bacillus was followed by the declaration 

 that it was the same in all mammalian 

 tuberculosis. This assumption was ap- 

 plied in the prophylactics of tuberculosis 

 before the important fact was ascertained 

 that there are varieties or races of tubercle 

 bacilli, and also that there exists a large 

 group of bacteria morphologically and 

 micro-chemically at least related to them. 

 Laymen and even medical men are having 

 difficulty to reconcile more recent findings 

 with the original teaching relative to the 

 identity of mammalian tubercle bacteria. 

 I do not refer to this disparagingly, for 

 progress is sometimes made by retreats as 

 well as by advances, but could the truth 

 concerning the tubercle group of bacteria 

 have been determined before the applica- 

 tion of the hypothesis that the etiological 



