SPONTANEOUS GENERATION 99 



The experiment was repeated by Pasteur who 

 confirmed Bastian's observations, although he 

 sought to explain them in a different manner. It 

 cost Pasteur and his co-workers, Joubert and 

 Chamberland, much work to get at the real solu- 

 tion of the difficulty. Chamberland showed that 

 in an acid medium some germs may be heated to 

 the boiling point, but will remain inert until the 

 medium is rendered alkaline when they again de- 

 velop. Again, germs, such as the spores of the hay 

 bacillus, may endure a temperature in an alkaline 

 medium several degrees higher than in a neutral or 

 acid medium. By heating to 115 or 120 C, the 

 materials used by Bastian it was found that all 

 bacterial development in alkaline urine was effec- 

 tually checked. Nowadays a practice is made of 

 heating to i2o°C. materials which it is important 

 to thoroughly sterilize. As Duclaux remarks, 

 "Bastian rendered a service to science; he lashed 

 it on its weak side, but he compelled it to ad- 

 vance." 



The interest aroused by these controversies and 

 the importance of the question involved drew sev- 

 eral investigators into the field. Many facts of 

 importance in regard to the vitality of germs under 

 different conditions were brought out as a result 



