DIFFICULTIES. 39 



urged to make improvements in object glasses, in order that 

 these minute, ever busy objects might be- better seen. And 

 the observer was compelled to await the tedious operations of 

 the maker of microscopes before he could proceed satisfactorily 

 with his work, and then usually found that the gain was but 

 slight. 



The subject became more and more complex the more it 

 was studied. It was found that in each decomposition there 

 were varieties of organisms. When one person found an 

 organism which he regarded as distinctive of a certain process 

 or disease, and published his results to the world, it was 

 usually quickly shown that this same organism was to be 

 found in widely different situations, entirely disconnecting it, 

 as a cause, with the processor disease claimed. 



This kind of disappointment recurred time after time, until 

 many of the best men turned away from the subject with dis- 

 gust, believing the theory incapable of demonstration. 



It was proven beyond question that many, at least, of the 

 bacteria were incapable of producing disease, and the view 

 that these forms were the accidents of the process, merely 

 accompaniments, were mere scavengers and had no causative 

 relation to it, gained wide credence. 



There was much reason for this view. It was in harmony 

 with what is seen to be going on around us every day. 

 Animals are found everywhere that do the work of the 

 scavenger. As the buzzards flock to the dead carcass, so the 

 bacteria swarm on the decompositions. 



However, a hawk is sometimes found among the buzzards, 

 for the want of the opportunity of attacking living prey, and 

 if the two were diminished in size to the mere specks -which 

 represent the bacteria, the work of distinguishing between 

 them would be difficult indeed. In surgery especially, cases 

 were continually occurring which seemed to indicate that the 



