THERMAL DEATH-POINTS 61 

the contained fluids after the first or second day ; 
and 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, 
together with a smaller number of Torule. But 
the fluids in the flasks which had been exposed to 
the higher temperatures of 140°, 1497, 158°, and 
167° F., showed not the slightest trace of turbidity, 
and no diminution in the clearness of the fluid while 
they were kept under observation—that is, for a 
period of twelve or fourteen days. 
One kind of conclusion only was to be drawn 
from these experiments, 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 con- 
tained in a fluid which had been proved to be 
eminently favourable for their growth and multipli- 
cation. If those inoculated fluids, which have been 
raised to 122 and 131 for ten minutes, are found 
in the course of a few days to become turbid, 
obviously the organisms cannot have been killed by 
such an amount of exposure to heat ; while if similar 
fluids, similarly inoculated, which have been raised 
to temperatures of 140°, 149°, 158°, and 167° F., 
remain sterile, such sterility seemed only explicable 
by the supposition that the multitudes of Bacteria 
and Torulz, introduced into the nourishing solutions, 
have been killed by exposure to these temperatures. 
Thus 140° F. (60° C.) was shown to be the thermal 
death-point of Bacteria and Torule. 
Somewhere about the same time Baron Liebig 
