222 MICRO-ORGANISMS AND DISEASE. [CHAP. 



particularly anxious to get hold of such an organism, in 

 order to see whether and how far it can again be made 

 harmless. For if ever there was a good case, a case in 

 which a previously harmless micro-organism had by some 

 peculiar conditions become specific, this was a case ; and 

 therefore it must be here possible by altering its conditions 

 of life again to transform it into a harmless being. The 

 theoretical and practical importance of such a case must be 

 evident to every one who has at all devoted any thought to 

 the relation of micro-organisms with disease. The whole 

 doctrine of the infectious diseases, I might almost say, is 

 involved in such a case, for if in one case it can be 

 unmistakably proved that a harmless bacterium can be trans- 

 formed into a pathogenic organism, i.e. into a specific virus 

 of an infectious malady, and if this again can under altered 

 conditions resume its harmless property, then we should at 

 once be relieved of searching for the initial cause in the 

 outbreak of an epidemic. But in that case we should be 

 forced to contemplate, as floating in the air, in the water, in 

 the soil, everywhere, millions of bacteria which, owing to 

 some peculiar unknown condition, are capable at once to 

 start any kind of infectious disorder, say anthrax (Buchner), 

 infectious ophthalmia (Sattler), and probably a host of 

 other infectious diseases, and thus to form the starting- 

 point of epidemics. And the only redeeming feature, 

 if redeeming it can be called, 'in this calamity would be 

 the thought that the particular bacterium would by and 

 by, owing to some accidental new conditions, again become 

 harmless. 



These were the reasons, and good reasons I think they 

 were, which prompted me to inquire into the jequirity 

 bacillus and jequirity ophthalmia, and after a very careful 

 and extensive series of experiments, to be described presently, 



