212 
ON THE GERM THEORY OF PUTREFACTION 
“AND OTHER FERMENTATIVE CHANGES* 
AFIER some introductory remarks referring to the various 
other theories which had been entertained on this subject, 
viz., the oxygen theory, the theory of spontaneous generation, 
and that of chemical ferments, the author stated that the re- 
searches of Pasteur had long since made him a convert to the 
germ theory, which attributes the alteration experienced by 
exposed organic substances to the development within them of 
minute organisms springing, like larger living beings, from 
parents like themselves ; and that this belief had been since con- 
tinually strengthened by the results of the antiseptic system of 
treatment in surgery, which he had founded on that theory asa 
basis. 
But his attention had been afresh directed to the subject about 
a year and a half ago by a remarkable paper by Dr. Burdon- 
Sanderson,t in which experiments were recorded, leading to the 
conclusion that Bacteria, unlike the spores of fungi, are deprived 
of vitality by mere desiccation at a moderate temperature, so that 
while a drop of water from ordinary sources or the contact of a 
moist surface is sure to lead to Bacteric development and conse- 
quent putrefaction in an organic substance susceptible of that 
change, the access of dust from exposure to the atmosphere in- 
duces merely the growth of fungi and comparatively insignificant 
chemical alteration. 
If this were true it would be needless to provide an antiseptic 
atmosphere in carrying out the antiseptic system of treatment ; 
and all that would be requisite in the performance of a surgical 
operation would be to have the skin of the part about to be 
operated on treated once for all with an efficient antiseptic, 
while the hands of the surgeon and his assistants and also the 
instruments were similarly purified ; a dressing being afterwards 
used to guard against the subsequent access of septic material. 
Thus the use of the spray might be dispensed with, and no 
one would rejoice more than himself in getting rid of that com- 
plication. 
Such being the practical importance of the conclusion referred 
to, he determined to subject it to a searching experimental 
test. 
The material first employed was urine, not boiled, as 
it had commonly been in previous investigations, but ob- 
tained, by a very simple antiseptic process, perfectly un- 
contaminated in its natural condition, in which it proved 
a far more favourable nidus for the development of or- 
ganisms than in the boiled state, as indeed might have been 
anticipated, since it contains unaltered the complicated organic 
substance termed the mucus, which has been sometimes regarded 
as a chemical ferment of urine. Nevertheless, when a wine-glass, 
together with a small porcelain evaporating dish, to serve as a 
cover, had been heated, like the vessels used by Dr. Sanderson, 
far above the boiling-point of water, and allowed to cool (a pro- 
cess conveniently designated by the term “heated”), and after- 
wards charged with the unboiled urine, and placed under a glass 
shade as an additionai protection against dust, it was found that 
the fluid remained free from organic development or putrefactive 
change for months, till at last it dried up into a saline mass. 
On the other hand, if a glass so charged was exposed to the air 
by removing the shade and cover for a while, organisms appeared 
in it of various kinds, and among the rest, in several instances, 
Bacteria. Thus it was shown on the one hand that bacteria 
might arise from atmospheric exposure, and on the other hand 
that a porcelain cover and glass shade afforded absolute security 
against the introduction of organisms from without. If, there- 
fore, the exposure of such a glass for a limited period chanced to 
lead to the introduction of any one organism unmixed with others, 
the opportunity was afforded of studying the behaviour of that 
organism, either in the same medium for a protracted period or 
in other media in similar glasses, inoculated by means of a heated 
pipette or glass rod. For it was found as a matter of experience 
that exposure for the few seconds or fractions of a second necessary 
for performing the inoculation or withdrawing a little fluid for ex- 
aminaticn did not involve any considerable risk of accidental 
contamination. 
Early in the investigation it was ascertained that the putre- 
faction of urine might take place without the occurrence of 
Bacteria, in presence of minute granules in irregular groups, in 
* Abstract of a communication made to the Royal Society of Edinburgh, 
April 7, 1873, by Prof. Joseph Lister, F.R.S. 5 
t See 13th Report of the Medical Officer of the Privy Council. 
Pa OTN ae 
NATURE — 
Or SA tes ; 
tens oe Or = 
a7 a 
| Fuly 10, 1873 
such numbers as to make the liquid milky; their organio 
nature being clearly proved by fissiparous generation observed to 
take place in them, though in a different manner from that 
which is seen in Bacteria. To this form of organism the name 
‘*Granuligera” has been provisionally applied. 
In one of the experiments related, two drops of water from — 
the tap having been added to a glass of Pasteur’s solution, the 
result was not in the first instance the general opalescence due 
to Bacteria in a liquid, but a deposit which proved to be a 
minute filamentous fungus producing abundant spores (conidia) 
on its branches. These spores after separation often produced 
young plants like their parents; but there were also seen in 
abundance precisely similar spores multiplying by pullulation 
like a Torula (to retain the old use of the name as applicable to 
organisms like the yeast plant).* And there were also present 
multitudes of moreslender filaments which were seen to break 
up into Bacteria, while in several instances these filaments were 
observed springing from spores undistinguishable from those of 
the fungus. 
The view that some filamentous fungi may give origin to both 
toruloid and Bacteric forms was soon afterwards confirmed by 
another experiment. + A “heated” wine-glass was taken into 
the open air during a drizzling rain, and the cover being lifted, 
some rain-drops were allowed to fall into it, after which un- 
contaminated urine was introduced. The result was the pro- 
duction of a pullulating delicate Torula, totally different 
from the yeast plant; forming a granular deposit on 
the sides of the glass, and an abundant scum, both in the 
urine and also in Pasteur’s solution on repeated inocula- 
tions. Portions of both liquids containing this organism having 
been set aside under circumstances permitting only very slow 
evaporation, they were examined again eight months later, when 
a delicate filamentous fungus was found in both, bearing conidia 
resembling the cells of tne Torula, while similar spores were 
seen multiplying by pullulation, and some of the buds were in a 
slender form undistinguishable in character from the Bacteria 
which in the case of the urine were observed swimming in the 
liquid. 
me organism which in the first instance was observed for 
weeks together growing as a mere Torula having thus, as it 
appeared, developed into a filamentous fungus, after remaining 
for months in the same solution, hopes were excited that a 
corresponding observation might be made with regard to the 
yeast-plant, and this led to a careful examination of alow white 
mould, referable to the genus Oidium, which was observed in a 
glass of Pasteur’s solution to which yeast had been added several 
weeks previously. The hope was disappointed, but some inter- 
esting facts were elicited: for the fungus was found to vary 
remarkably according to the quality of the medium in which it 
grew, having sometimes the aspect of an Oidium with fructi- 
fying filaments, sometimesa purely filamentous structure, some- 
times a loosely-jointed growih producing abundant oval spores 
destitute of nuclei, and often pullulating like a Torula, and 
lastly a purely toruloid form of an entirely different aspect, com- 
posed of spherical nucleated cells, cccurring in urine, and 
operating as a power‘ul putrefactive ferment upon that fluid. Yet 
totally dissimilar as the different forms of this fungus might ap- 
pear, their identity was demonstrated by observing with the 
microscope the actual growth of one from another when trans- 
ferred to a new medium on aslide of thick glass excavated round 
acentral island, so as to provide a sufficient supply of oxygen 
to last the growing fungus for a long period. ‘The sliie and its 
thin covering glass were heated between metallic plates to diffuse 
the heat and prevent cracking of the glass, so arranged as to 
guard against the entrance of dust during cooling, and all instru- 
ments, such as forceps and needles, employed in the subsequent 
manipulations, were ‘‘heated” before beiog used, the thin covering 
glass being luted down with melted paraffin applied with a hot steel 
pen. ‘Glass gardens” of this construction stocked with various 
organisms in various media proved extremely useful means of 
investigation. Samples of the organism introduced were sketched 
with camera lucida immediately after introduction, and their 
subsequent development observed with perfect precision. In 
this way, in the case of the Oidium, spherical nucleated cells of 
* The toruloid pullulation of spores of some minute filamentous fungi had 
been previously observed by De Bary. See ** Morphologie und Phys.ologiz 
der Pilze,” &c., von. Dr, A. de Bary, p 183. 
t This view has been expressed by various other authors, but has been 
hitherto incapable of demonstration in consequeuce of the uncertainty 
whether things which seem to grow from one organism may not be merely 
the result of the accidental presence of others. 
