186 THE EVOLUTION OF LIFE 
Micrococci can survive an exposure in fluids to 
100° C. Yet micrococci alone always appeared. 
(6) Ls ordinary unbowled liquor potasse a germ- 
containing medium ? 
That liquor potassze when boiled is not, as Pasteur 
at first contended, a germ-containing medium, is 
obvious from the fact which I mentioned to him, 
that when in too small a quantity, and even when 
in too large a quantity, it would not fertilise boiled 
urine on addition thereto. He did not venture to 
attempt any proof of his contention. He might 
easily have recognised his error in regard to this, 
by doing what I have since done, in order to show 
that even liquor potassze which has not been heated 
is a germ-free liquid. 
I inoculated twelve flambé flasks, plugged with 
cotton wool, containing sterile urine, which had been 
in the incubator unchanged for six or seven days,! 
each with a drop of liquor potasse taken with a 
flambé pipette from a bottle which had been very 
frequently opened and exposed to the air. These 
tlasks were placed in the incubator at a temperature 
of 110 F., and after twenty-four hours the fluid in 
one of them was found to be turbid with short 
Bacilli, that in all the others being clear.2 At the 
1 They were some of the fluids in which I had been testing the 
death-point of Bacilli spores, as detailed in Chapter x. 
2 Of course, there is always a slight risk of accidental contamina- 
tions during the removal of a cotton wool plug, to permit of inoculation, 
and its subsequent reintroduction, though I tried to guard against 
this, as much as possible, by brushing round the top of the flask 
between its edge and the plug with a camel hair pencil wet with a 
20 per cent. solution of carbolic acid. 

