100 LOUIS PASTEUR 



of efforts to arrive at a definite settlement of the 

 problem. It was found that in a dried condition 

 germs may resist degrees of heat considerably 

 above the boiling point. Bacteria may lodge upon 

 the sides of glass vessels or the necks of glass re- 

 torts and remain there in a living condition while 

 the fluid contents have been subjected to boiling. 

 As Duclaux observes, "The heating to 120 C. of 

 a flask half full of liquid may sterilize only the 

 moistened part, allowing life to persist in the 

 regions which are not in contact with the liquid. 

 In order to destroy everything, it is necessary to 

 subject the dry walls to 180 C. Hence the utility 

 of flaming all the receptacles used in microbiology, 

 and behold once more a practice arising, like the 

 autoclave, from the laboratory of Pasteur, and 

 which, along with it, established a good technique 

 and made the future secure." 



As knowledge of micro-organisms became more 

 extensive and precise, the position of the opponents 

 of spontaneous generation grew steadily in strength. 

 In England the problem was investigated with great 

 ability and manipulative skill by the physicist, 

 John Tyndall, who approached the problem by a 

 route very different from that of Pasteur. Tyndall 

 was led to it from his investigations of the way in 



