CHAPTER II 



HOW THE IMPORTANCE OF MICROORGANISMS 

 WAS DISCOVERED 



Louis Pasteur, bom in 1822 in the family of a simple 

 French tanner, was destined to become one of the most 

 picturesque and most famous men of the nineteenth cen- 

 tury. His keen scientific mind led him to explore new fields 

 hitherto uninvestigated, and thus he became one of the 

 world's leading scientists ; while his great depth of feeling 

 led him into those phases of science which gave most 

 promise of relieving suffering, and he may well be con- 

 sidered one of the greatest benefactors to mankind that 

 the world has ever known. Not many of his discoveries 

 had a direct bearing on household problems ; but indirectly 

 they are of importance in every home, and every one should 

 know about him. 



Pasteur began his career as a chemist, and he gave 

 promise, while still a young man, of becoming one of the 

 leading chemists of his day. But he happened then to get 

 interested in fermentation, not dreaming that in this way 

 he was headed away from chemistry. The study of fer- 

 mentations was a part of chemistry in those days, and it 

 was not imtil Pasteur himself had founded the science of 

 bacteriology that any one thought of the two subjects as 

 distinct. 



His study of fermentations brought him into direct con- 

 troversy with one of the most prominent chemists of his 



