NATURE OF THE EVIDENCE. 43 



widely entertained ; and now the antiseptic method of Lister 

 was found to remove the difficulty, and render the treatment 

 of wounds in such hospitals as effective and safe as the same 

 class of wounds in private practice, and in most cases even 

 more so. This grand achievement of the germ theory lent 

 an immense impulse to the study of the subject. Every great 

 surgeon became a student of fermentative change, and of the 

 influence of living organisms, no matter what his bias on the 

 subject. As might reasonably be expected a corresponding 

 advance has been attained. 



Up to that time no one particular organism had been 

 singled out and proven to stand in a causative relation to 

 any one disease. 



But now the study of the individual character of the 

 organisms found in wound secretions, and in the tissues 

 immediately after death from particular diseases, sprang to 

 the front, and has been carried forward by the most acute 

 minds of our times. 



NATURE OF THE EVIDENCE. 



We may now turn our attention to the examination of the 

 evidence upon which these views were based. The theory, so 

 far as it relates to the production of disease, has been founded 

 on fragmentary evidence, not upon demonstration. And it 

 must be said, also, that much of this fragmentary evidence 

 has been of the nature of what lawyers would call circum- 

 stantial evidence. The nature of the evidence, as a matter of 

 fact, may be thus stated : It had long been believed that fer- 

 mentation, decomposition, ruiasm and contagion were caused 

 by processes similar or identical in their nature. It has been 

 proven that fermentation and decomposition are dependent 

 upon the life and growth of certain microscopic organisms. 

 Therefore, miasmatic and contagious diseases are caused by 

 3* 



