106 THE DEATH-POINT OF BACTERIA 
itself appreciably later, and advanced much more 
slowly than in similar mixtures which had not been 
heated above 131° F.; whilst it has commenced even 
later, and progressed still more slowly, when occurring 
in mixtures previously heated to 149° F. Such facts 
might be accounted for by the supposition that ex- 
posure in these organic fluids to the slightly higher 
temperature suffices to retard the rate of growth and 
multiplication of the living units of the inoculating 
compound, although the facts are equally explicable 
upon the supposition that the later and less energetic 
putrefactions are due to the sole influence of the 
mere organic matter of the inoculating compound. 
2. So far as the evidence embodied in the Tables 
goes, it tends to show that the more unstable dif- 
ferent specimens of similar infusions are (that is, the 
stronger they are), the more rapidly and frequently 
does late turbidity ensue, and the more this late 
turbidity approaches, both in time of onset and in 
rate of increase, to that which occurs when inoculated 
infusions are not heated to more than 131° F.—when 
both living and not-living elements of the inoculating 
compound act conjointly as ferments. Such facts 
show quite clearly that where the intrinsic or pre- 
disposing causes of change are strong, there less 
potent exciting agencies are more readily capable of 
coming into play; but they still do not enable us 
