ORIGIN OF LOWEST ORGANISMS. 55 



after two or three more days, the fluid in each became 

 quite turbid and opaque, owing to the presence and 

 multiplication of myriads of Bacteria, Vibr tones and 

 Torulcz ; the fluids in the flasks, however, which had 

 been exposed to the higher temperature of 140, 149, 

 158, and 167 R, showed not the slightest trace of 

 turbidity, and no diminution in the clearness of the 

 fluid while they w r ere kept under observation that 

 is, for a period of twelve or fourteen days. One kind 

 of conclusion only is to be drawn from these experi- 

 ments, the conditions of which were in every way 

 similar, except as regards the degree of heat to which 

 the inoculated fluids were subjected seeing that the 

 organisms were contained in a fluid, which had been 

 proved to be eminently suitable for their growth and 

 multiplication.* If inoculated fluids which have been 

 raised to 122 and 131 F. for ten minutes, are found 

 in the course of a few days to become turbid, then, 

 obviously, the organisms cannot have been killed 

 by such exposure ; whilst, if similar fluids, similarly 

 inoculated, which have been raised to temperatures 

 of 140, 149, 158, and 167 F. remain sterile, such 

 sterility can only be explained by the supposition 

 that the organisms have been killed by exposure to 

 these temperatures. 



Some of these experiments have been repeated 



* Fluids which had remained sterile would always, in the 

 course of thirty-six or forty-eight hours after inoculation with 

 living Bacteria, become more or less turbid. 



