
IMPORTANT NEW EXPERIMENTS 145 
periments remains clear and apparently unaltered 
for an indefinite time ; while where the potash has 
been allowed to operate upon the sterilised fluid, it 
becomes turbid, lighter in colour, and swarms with 
organisms, on an average, in from 18 to 36 hours. 
The period, with different urines, is sometimes less 
and sometimes more, though no great prolongation 
occurs except through some alteration having been 
brought about in the proper ratio that should exist 
between the acidity of the boiled fluid and the 
amount of liquor potasse which is added thereto. 
Such delays in the occurrence of fermentation were 
common enough during my earlier trials with this 
method ; but now that I have more carefully studied 
and ascertained some of their causes, I am generally 
able to obviate them and ensure the supervention of 
fermentation within two or three days. 
This fermentation of urine to which liquor-potassz 
is added after boiling, unquestionably takes place 
more readily in a flask plugged with cotton-wool 
than in a sealed retort from which air has been ex- 
pelled by boiling. And that the slightly diminished 
readiness of the fluid to ferment in the airless retort 
is attributable to the absence of atmospheric oxygen, 
seems to be confirmed by other. experiments, in 
which an increased readiness to change is exhibited 
by urine and liquor potassze under the influence 
of nascent or less-diluted oxygen, liberated by 
electrolysis—the retorts in this case being provided 
with platinum electrodes.! 
I have also in two experiments with closed flasks 
1 L0c. Ctl. Pps'9-12. 
K 
