ae SS Pe Ee eee 
274 
these mere thin films of fluid dead ferments are as incapable of 
operating upon the organic fluids as they are upon the ammonic- 
tartrate solutions. : 
4. Because, in the case of the inoculation of fluids which are 
not easily amenable to the influence of dead ferments, such as 
asolution containing ammonic tartrate and sodic phosphate, this 
delayed turbidity does not occur at all. Such inoculated fluids 
become rapidly turbid when heated to 131° F., though they 
remain clear after a brief exposure to a temperature of 140° F. 
When the living units in the inoculating compound are boiled, 
there is nothing left to induce turbidity in such solutions. The 
mere fact that these fluids do not undergo change when ex- 
posed to the air proves conclusively that they are very slightly 
amenable to the influence of the ordinary dead organic particles 
and fragments with which the atmosphere abounds. The 
absence of delayed turbidity in these fluids serves, therefore, to 
throw much light upon the cause of its occurrence in the organic 
infusions. 
5. And, lastly, I can adduce crucial evidence supplied by the 
“Method of Difference,” speaking with its accustomed clear- 
ness. Two portions of the same hay- or turnip-infusion can be 
inoculated in such a manner as to supply us with the information 
we require. In the one case we mayemploy a drop of a turbid 
ammonic-tartrate solution previously heated to 140° F., in which, 
therefore, the living units would certainly be killed : whilst in 
the other we may add an unheated drop of the same turbid saline 
solution to the organic fluid, and then heat this mixture also to 
the temperature of 140°°F. The comparative behaviour of these 
two inoculated fluids (placed, in the ordinary manner, in pre- 
viously boiled corked phials) should be capable of showing us 
whether the living elements of the inoculating compound were 
able to survive when heated in the organic infusion. If they did 
survive, the fluids inoculated in this manner ought to undergo 
putrefaction earlier and more rapidly than those inoculated with 
the drop of turbid fluid, in which we know that the Bacteria, 
Vibriones, and their supposed germs would have been reduced 
toastate of potential death. With the view of settling this 
question, therefore, the following experiments were made :— 
Description of Experiments. Results. Inferences. 
That boiled ammonic-tartrate 
solution is a fluid inoculable 
by living Bacteria, &c., and 
favourable for their growth 
and rapid multiplication. 
That Bacteria, Vibriones, 
and thcir supposed germs 
are either killed or deprived 
of all power of multiplica- 
tion when heated to rgo” F. 
in this fluid. 
The precisely similar beha- 
viour of the turnip- and 
hay-infusions of series C 
and series D respectively 
shows that Bacteria, Vi- 
briones, and their sup- 
posed germs are as ino- 
perative in series D as 
they are known to be in 
series C ; whilst the beha- 
viour of the hay-infusions 
shows that they are little 
amenable to the influence 
of the drop of the saline 
fluid when its living units 
are killed. 
Shows that a heat of 131° F, 
is not sufficient to kill Bac- 
| 
A. Boiled ammonic-tartrate|Turbid in 40 
solution, inoculated with an} hrs, 
unheated drop of a similar 
solution turbid with Bacteria, 
c. 
B. Boiled ammonic-tartrate 
solution, inoculated with a 
drop of a turbid saline solution 
previously heated to rqo° F. 
Clear at Cg 
tion of &t 
day. 
Turnip-infu- 
sions turbid 
in 2} days. 
Hay-infusions 
clear at expi- 
ration of 8th 
day. 
Turnip-infu- 
sions turbid in 
24 days. 
Hay-infusions | 
clear at expi- 
ration of 8th 
day. 
C. Boiled turnip- and hay- 
infusions, inoculated with a 
drop of a turbid saline solution 
previously heated to ryo° F. 
D. Boiled turnip- and hay- 
infusions, inoculated with aj 
drop of an unheated turbid 
saline solution, the inoculated 
fluid being subsequently heat- 
ed to r40° F 
E. Boiled turnip- and hay-/Turnip-infu- 
infusions, inoculated with aj sionsturbidin 
drop of an unheated saline} 28 hrs. fo teria, Vibriones, and their 
solution, the inoculated fluid Hay-infusions supposed germs in organic 
being subsequently heated to| turbid in 38 infusions, and, again, that 
13r Ff. hrs. turnip-infusions are more 
rapidly influenced by such 
an inoculating agent than 
some hay-infusions.* 
No experiments could speak more decisively. Those of series 
B show that Bacteria, Vibriones, and their supposed germs are 
either actually or potentially killed when heated to 140° F. in 
the neutral saline fluid, which the experiments of series A show 
* These experiments of series C, D, and E were many times repeated with 
specimens of the same turnip- and hay-infusions, the specific gravity of the 
former being about roo8 and that of the latter 1005. Different specimens of 
hay especially vary so much that it becomes absolutely essential to use 
portions of the same infusion for the comparative experiments of these diffe- 
rent series, 
BO Bie Aha) SON 
NATURE 
[Fuly ai 187 
to be eminently favourable for their growth and reproductior 
Being certain, therefore, that the living units are killed in the 
drops with which the fluids of series C were inoculated (becaus 
they were drops of the same fluid as was employed in series B 
we may be equally certain that the turbidity and putrefaction 
which did ensue in the turnip-solutions of series C were du 
to the influence of the mere dead constituents of these drops 
the turbid saline fluid ; whilst, seeing that the behaviour of th 
fluids of series D was precisely Similar to those of series C, 
have a perfect right to infer that this series of fluids (D) was < 
devoid of living units as those of C are known to be—that i 
that Bacteria, Vibriones, and their supposed germs are killed b 
the temperature of 140° F. in organic fluids, just as they are j 
saline fluids, although, as shown by the experiments of series | 
they do not succumb toa heat of 131° F. 
The evidence now in our possession shows, therefore, 
whilst the temperature at which living ferments cease to 
operative varies within very narrow limits (131°--140° F.), th 
which destroys the virtues of non-living ferments varies withi 
much wider limits, and depends not only upon the amount ¢ 
heat employed, but also upon the nature of the putresci 
fermentable liquid to which such ferment is added, in conj 
tion with the degree of heat and other conditions to wh 
the mixture is subsequently exposed.* Here, therefore, 
have evidence as to the existence of a most important di 
ference between living and not-living ferments, which ha 
always been either unrecognised or more or less delib 
rately ignored by M. Pasteur and his followers. This differens 
is, moreover, thoroughly in accordance with the broad physic 
chemical theory of fermentation which has been so ably 6 
pounded by Baron Liebig and others, and the truth of whi 
may now be regarded as definitely established. According | 
this theory ‘‘living” matter, as a ferment, would take rar 
merely as a chemical compound having a tolerably definite cot 
stitution ; and this, we might reasonably infer, would, Iil 
other chemical compounds, be endowed with definite prope 
and amongst others that of being decomposed or radi 
altered by exposure to a certain amount of heat. Looked a 
also from this essentially chemical point of view, it would b 
only reasonable to expect that the molecular movements of livin 
ferments with a lowered vitality might not be more marked ¢ 
energetic than those which many not-living organic substance 
are apt to undergo ; and this being the case, we might exp 
that there would often be a great practical difficulty in asce 
taining whether a ferment belonging to the arbitrary and artifici: 
(though, in a sense, justifiable and natural) category of “ living 
things had or had not been in operation. d 
Dr. Bastian then refers to certain statements made by — 
Pasteur, and afterwards classifies the various fermentable fui 
under three main divisions :—I. Self-fermentable fluids; I 
Fluids which will not ferment without the aid of unheate 
organic matter, either not-living or living; III. Fluids whi 
will only ferment under the initiating influence of living matter 
Dr. Bastian’s conclusions from these investigations are thi 
expressed :— 
Thus it can now be proved, by evidence of a most unmis 
takable nature, that the process ef putrefaction which invariabl 
occurs in previously boiled putrescible infusions contain 
flasks with narrow but open necks is not commonly (is, perl 
only very rarely) initiated by living germs or organisms d 
from the atmosphere ; it can also be proved that putrefac 
and the appearance of swarms of living organisms may o 
in some boiled fluids when they are simply exposed to air whiel 
has been filtered through a firm plug of cotton-wool or thous 
1 
. 
the narrow and bent neck of a flask, to air whose particles hay 
been destroyed by heat, or even in fluids hermeticaliy seal 
* See “The Beginnings of Life,” vol. i. p. 437. 
+t See, for instance, all M. Pasteur’s celebrated experiments in whicl 
had recourse to an “ensemencement des poussiéres qui existent en 
sion dans I'air,” as recorded in chaps. iv. and v. of his memoir in “A 
Chimie et de Physique,” 1862. M Pasteur was engaged in an investiga 
one of the avowed objects of which was to determine whether fermentatic 
could or could not take place without the intervention of living organisi 
which M. Pasteur held (in opposition to many other chemists) to be the 
true ferments. In his inoculating compound (dust filtered from the 2 
sphere), there was, as M. Pasteur was fully aware, a large amount of 
his scientific opponents considered non-living ferment, whilst possibly ré 
existed a certain number of living ferments. In explaining the results of hi 
experiments, however, M. Pasteur and others thought he was pursuing : 
logical and scientific method when he attributed these results to the. 
of the possibly existing element of the inoculating compound, whils 
ignored altogether the other element which was certainly present in ¢ 
ratively large quantity, and the testing of whose efficacy was the ost 
object of his research, ~ 
