138 The Mieroscopic Germ Theory of Disease. By H. C. Bastian, 
abnormal conditions. Grapes, for instance, suspended in an atmo- 
sphere of carbonic acid will undergo fermentation, so as to generate 
alcohol and other products, even without the presence of torulae or 
allied organisms. Other fruits and vegetables treated in the same 
way behave more or less similarly. Organic multiplication of 
independent organisms has therefore now been shown by Pasteur 
himself and his followers, not to be an essential factor in the 
process of fermentation. With this admission I believe it will be 
found impossible hereafter consistently to entertain an exclusively 
" vital " theory of fermentation, and equally impossible to resist 
accepting the broader physico-chemical theory, and with it the 
almost inseparable correlative doctrines of archebiosis and hetero- 
genesis. 
M. Pasteur, in fact, now proves that fermentation takes place 
under the influence of altered chemical (nutritive) processes taking 
place in unhealthy vegetal tissue, just as we know that similar pro- 
cesses may be initiated under the influence of a physico-chemical 
process brought about by finely divided platinum. As Dobereiner 
pointed out, this material "has the power — and many organic 
substances have a similar power — of absorbing oxygen from the air, 
and bringing it into a condition in which it can unite with other 
substances with which it would not otherwise enter into combina- 
tion at low temperatures."* 
And MM. Lechartier and Bellamy, following up the recent 
experiments of Pasteur, have found t that in these modified processes 
of fermentation, taking place in vegetal tissues, independent 
organisms, though they are usually absent at first, not unfrequently 
make their appearance after a time. In the process as it occurs in 
beet-root and in the potato, on the other hand, bacteria habitually 
spring into existence or reveal themselves in great abundance soon 
after the commencement of a well-marked process of fermentation. 
M. Pasteur will, I suspect, find it difficult consistently to account 
for these facts without admitting his long-postponed acceptance of 
doctrines of "spontaneous generation." 
2. Eespecting the degree of relationship existing between fer- 
mentations and zymotic processes, something more definite may 
now be said. Between the ordinary previously known forms of 
fermentation and zymosis, a most fundamental difierence exists 
which has hitherto been far too much lost sight of. It is this: 
"Whereas in an ordinary fermenting fluid the changes initiated by a 
ferment take place in a mere isolated mixture of organic substances, 
in zymotic processes the changes initiated by contagium occur in 
the fluids and tissues of a complex living body. That this latter 
fact does exercise a very important influence, and that the two 
* * Beginnings of Life,' vol. i. p. 409. 
t * Compt. Rend.,' November 2, 1874. 
