DEVELOPMENT OF BACTERIOLOGY 9 



briefest period of time. The infusion of meat had been 

 protected from the entrance of bacteria after it had been 

 heated; therefore it was believed the forms found in the 

 decomposing infusion must have arisen in some way from 

 the lifeless material. 



Many experimenters tried to disprove this theory. 

 Schultze, in 1836, heated infusions to the boiling-point, and 

 the air that entered his flasks when removed from the fire 

 was pass.-d t hrough strong acid or alkali. In 1837, Schwann 

 passed the air that entered the flasks through tubes heated 

 by a direct flame. Schroeder and von Dusch, in 1853, 

 plugged the tubes leading from the flasks with cotton wool, 

 which filtered the air as it was drawn into the flasks wlu-n 

 they cooled. Usually infusions thus treated did not decom- 

 pose. 



The adherents of the theory claimed that the exposure of 

 air to the high temperature of the heated tube, to acid or 

 alkali, or even to cotton wool, removed some life-maintaining 

 principle therefrom. It was not possible by such experi- 

 ments to disprove the theory. In 1860, the Paris Academy 

 of Science ottered a prize for an attempt to throw new light 

 by suitable experiments on the question of spontaneous 

 generation. 



Pasteur, the father of bacteriology. Louis Pasteur was 

 born in the Jura district of Prance in 1822. He was a dili- 

 gent student of chemistry, and became interested in the ef- 

 fect of certain crystalline substances and their solutions on 

 polarized light. Among the substances he studied was tar- 

 taric acid and its salts, products of one of the great fermen- 

 tation industries, the wine industry. In 1854 he was made 

 a member of the Faculty of Sciences in the University of 

 Lille, a great industrial city. He began the study of the 

 manufacture of alcohol from beet-sugar. In 1857 he read 

 a paper on the lactic-acid fermentation. He had discovered 



