ROBERT KOCH I9 



its failure upon his personal fame that concerned him ; he 

 had become genuinely attached to the little boy and was 

 prajang with all his heart that he might be saved. The 

 boy lived. All the world to-day has heard of those sleepless 

 nights of Pasteur and how he finally became convinced that 

 either his treatment or some unknown miracle had saved 

 the boy. To-day the Pasteur treatment is used so generally 

 that we know it was no miracle; human ingenuity had 

 conquered a dreaded disease. 



While Pasteur in France was making these discoveries, 

 Germany also produced a bacteriologist who achieved in- 

 ternational reputation, Robert Koch. Koch has never been 

 called the father of bacteriology ; but he made great dis- 

 coveries. He learned the cause of tuberculosis, among 

 other things ; but in another way he made a still greater 

 contribution, which the public has never appreciated. Bac- 

 teria are such tiny objects that, when they were discovered, 

 it was a puzzle how any one could ever study them. You 

 cannot pick one up with your fingers or even with the 

 tiniest forceps made; you can barely see it with the 

 highest-powered microscope. It took a genius like Pasteur 

 to study them. Then Koch showed a simple method. To 

 be sure you cannot handle a single bacterium ; but Koch 

 showed how you could fasten it down on a plate of jelly 

 so that it could not move and its descendants could not 

 swim away from it until finally a mass of bacteria (a 

 colony) developed large enough to be seen with the naked 

 eye. There was something large enough to handle; you 

 could not pick up a single organism, but you could make 

 a culture from one of these colonies, and if the work were 

 done carefully you could be reasonably sure that the cul- 



