SANITARY NOTES ON POTABLE WATER. 55 5 
know, been the subject of separate inquiry, although numerous 
investigators have here and there commented upon it. 
This is the question whether ordinary putrefaction or fer¬ 
mentative processes, without being their original cause, may 
yet have a bearing on the diseases which are commonly caused 
zymotic. 1 have devoted a great deal of time to study indis- 
crimately the views and opinions of a number of prominent 
scientific gentlemen on this subject, which is of course largely 
a matter of speculation. Considering that preventive sani¬ 
tary measures must to some extent depend upon its issue, I 
think it may not be without interest to give a short summary 
of my notes. 
There are three possibilites. Fermentation may either 
favour or it may counteract the virulence of the specific 
contagia; or lastly, there maybe no connection at all between 
them. To state a case let us suppose we are dealing with 
typhoidal or choleraic discharges, which are in a state of 
gradual fermentation. The question then is, will the viru¬ 
lence of the the contagia be increased or diminished, or will 
it not be affected at all by being surrounded with putrid 
faecal matter. 
I have been able to discover only two statements to the 
effect that fermentation and contagia are antagonistic. One 
of them is made incidently in Dr. Maclagan's ‘ Germ Theory/ 
He says on page 22 :—“The fact that contagious fluids are 
most potent in the fresh state, and that their virulence 
diminishes in intensity as bacteria increase therein, is looked 
upon by Dr. Bastian as fatal to the germ theory.” I have 
not succeeded in tracing this quotation in Dr. Bastian's 
publications, but think I shall presently be able to show 
that he can scarcely hold such views without qualification. 
The other statement is by Davaine.* He found that whilst 
the disease, known by the name of " blood/' can always be 
reproduced in a healthy animal by inoculation of fresh dis¬ 
eased blood, the latter loses its infective power whenever it 
become putrid. In very hot weather he found this to be the 
case, even after the blood had been kept for only thirty-five 
hours. 
We must first bear in mind that it is possible or even 
probable that the specific contagion of different diseases may 
exhibit a different behaviour under the influence of ferment¬ 
ing matter. Secondly, as a matter of course, fermentation 
is capable of redissolving all organic matter without excep¬ 
tion into its more elementary inorganic constituents. If we 
therefore suppose that the specific virus is of an organic, or 
* Bastian, ‘ Beginnings of Life,’ i, p. 362.^ 
