i 
XI PHENOMENA OF ORGANIC NATURE 389 
taneous generation. He had succeeded in catching 
the germs and developing organisms in the way 
he had anticipated. 
— 
It now struck him that the truth of his conclu- 
sions might be demonstrated without all the appa- 
ratus he had employed. To do this, he took some 
decaying animal or vegetable substance, such as 
urine, which is an extremely decomposable sub- 
stance, or the juice of yeast, or perhaps some other 
artificial preparation, and filled a vessel having a 
long tubular neck with it. He then boiled the 
liquid and bent that long neck into an § shape or 
zig-zag, leaving it open at the end. The infusion 
then gave no trace of any appearance of spontaneous 
generation, however long it might be left, as all 
_the germs in the air were deposited in the begin- 
ning of the bent neck. He then cut the tube close 
to the vessel, and allowed the ordinary air to have 
free and direct access ; and the result of that was 
the appearance of organisms in it, as soon as the 
infusion had been allowed to stand long enough to 
allow of the growth of those it received from the 
air, which was about forty-eight hours. The: re- 
: sult of M. Pasteur’s experiments proved, therefore, 
in the most conclusive manner, that all the appear- 
_ ances of spontaneous generation arose from nothing 
~ more than the deposition of the germs of organisms 
prbich were constantly floating in the air. 
: 
To this conclusion, however, the objection was 
' made, that if that were the cause, then the air 
