There are two points of some practical interest to which I desire for
a few moments to call your attention. The former has reference to the
group of organisms to which I have for so many years directed your
attention, viz., the "monads," which throughout I have called
"putrefactive organisms."

There can be no longer any doubt that the destructive process of
putrefaction is essentially a process of fermentation.

The fermentative saprophyte is as absolutely essential to the setting
up of destructive rotting or putrescence in a putrescible fluid as the
torula is to the setting up of alcoholic fermentation in a saccharine
fluid. Make the presence of torulæ impossible, and you exclude with
certainty fermentative action.

In precisely the same way, provide a proteinaceous solution, capable
of the highest putrescence, but absolutely sterilized, and placed in
an optically pure or absolutely calcined air; and while these
conditions are maintained, no matter what length of time may be
suffered to elapse, the putrescible fluid will remain absolutely
without trace of decay.

But suffer the slightest infection of the protected and pure air to
take place, or, from some putrescent source, inoculate your sterilized
fluid with the minutest atom, and shortly turbidity, offensive scent,
and destructive putrescence ensue.

As in the alcoholic, lactic, or butyric ferments, the process set up
is shown to be dependent upon and concurrent with the vegetative
processes of the demonstrated organisms characterizing these ferments;