NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
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Scientific Memoirs by
them occurred within the peritoneal cavity, numerous examinations and cultiva-
tions of the peculiar adhesive peritoneal secretion in cases of cholera were
made. In no instance were Schizomycetes of any form recognizable in any
considerable numbers in the fresh materials. In some cases a very few long,
straight filaments were present, in some a few patches of Micrococci occurred,
and in one case, at all events, minute groups of small curved Bacilli, resembling
choleraic commas, were present in small numbers. In no instance did choleraic
commas appear in the cultivations, but in one a distinct and peculiar curved
Schizomycete form was developed. The commas were larger and thicker than
choleraic ones; they did not liquefy the gelatine of the basis, but slowly
formed thick, prominent, shining growths of a pale salmon colour. When
subcutaneously injected into the bodies of guinea-pigs they produced no
appreciable effects.
IV.—Results of examinations of old specimens of Choleraic tissues
for " the Cambridge Cholera Fungus."
After the publication of the "Preliminary Report on the Pathology of Cholera
Asiatica (as observed in Spain in 1885)" by Messrs. Roy, Brown, and
Sherrington in the Proceedings of the Royal Society, 1 a n d t h e d i s c u s s i o n t o
which it gave rise in the pages of Nature,2 a c a r e f u l e x a m i n a t i o n w a s m a d e i n
order to ascertain whether any organisms, such as those described and figured
in the report, could be detected in choleraic tissues in Calcutta. A consider-
able amount of time was devoted to the matter, and a very large number of
preparations were made, as, quite apart from any special choleraic interest,
it appeared to be well worth while to expend time and trouble in the attempt
to obtain specimens of organisms of such unique characters as apparently to
resemble indifferently members of the Family Chytridiaceae and Bacteria in "an
involution form." The materials examined, like those in which the organisms
are described as occurring, were derived from cases of cholera which occurred
in 1885 and had been continuously preserved in absolute alcohol from the time
at which the post-mortem examinations were made shortly after death. They
consisted of small portions of the duodenum, jejunum, ileum, cæcum, liver,
spleen, kidney, and mesenteric glands. Numerous sections were cut from the
specimens belonging to six different cases, and various stains were employed,
special attention being naturally given to staining with methylene blue, particu
larly after Löffler's method, but in no single instance could a trace of any
organisms resembling "the Cambridge Cholera Fungus" be detected. The
examinations further showed anew how exceptional it is in Calcutta to meet
with cases in which there is any penetration of the intestinal tissues by the
1 Vol . XLI , No. 247, p .1 73. 2Vol . 35, pp. 171, 271, 295, 319.
Medical Officers of the Army of India. 7
choleraic commas, for in not a single case was there any evidence of the
presence of any such phenomenon.
V.—On 'Fungal contamination of the Gelatine and Agar-Agar in
sterilised tubes during the Rains in Calcutta.
On returning to Calcutta in 1886, after an absence of more than two months
during the rainy season, I found that almost all the sterilised tubes of com-
mon gelatine and agar-agar which I have left in the laboratory showed
manifest signs of contamination, the surfaces of the nutritive media being
covered with conspicuous white growths. As many of these 'tubes had
remained for months previous to my departure in the end of the hot weather
without showing a trace of any contamination, it appeared at first sight difficult
to account for the phenomenon. Microscopical examination of the nature of the
growths present in the tubes appeared, however, to afford a plausible explanation
of it. It was ascertained that in no case did the growth consist of Schizomy-
cetes, but that they were composed of 'filamentous mould-fungi. Now, the
conidia of such bodies are very much more abundant in the air in Calcutta
during the rains than at other times, and the general moisture of the surfaces
on which they may be deposited favours their germination. The infected tubes
were closed by two superimposed plugs of sterilised cotton wool, but were
not capped, so that particles of atmospheric dust were free to be deposited on
the upper surfaces of the superior plugs.
During the cold and hot weather, the number of conidial elements thus
deposited was relatively small and the cotton wool was too dry to favour their
germination, and at this time contamination did not occur. With the rains,
however, new conditions were established: the numbers of fungal elements
liable to deposition became greatly increased and the cotton wool became
gradually moist enough to allow of those which were deposited germinating
and to form a medium in which continuous mycelial filaments could readily
spread. Gradual penetration of the entire thickness of the plugs by mycelium
was therefore liable to occur, and when this had been established, any free
conidial elements arising on the under surface of the inferior 'plug would of
course be very likely to be deposited on the surface of the nutritive medium
in the lower part of the tube. The plugs remained effective obstacles to the
access of Schizomycetes, because they did not present suitable nutritive mate-
rials to allow of growth of Schizomycetes in such quantities as to penetrate
the thick obstructive strata. The higher fungi were at an advantage because
of the greater amount of store-nutritive materials which their ordinary repro-
ductive elements contain, 'and because of their mode of growth which permits
of the continuous progress of the protoplasm from one area to another, and
therefore render it possible that the comparatively small amounts of nutritive
materials present at different points should be successively utilised in assimi-
lation.
8
Scientific Memoirs by
VI.—On a destructive blight in Tea plants dependent on the invasion
of the tissues of the roots by the mycelium of a fungus.
During the cold weather of the current year I was asked by Dr. King, the
Superintendent of the Royal Botanical Garden, Calcutta, to examine some
specimens of root-blight in tea which had been submitted to him for an opinion
as to the nature of the disease. A thoroughly decisive determination of certain
points in connection with the disease could only be attained by means of experi-
ments on infection of living plants which I have had no opportunity of attempt-
ing in Calcutta,, and others certainly call for more extended observation than it
has yet been possible to give to them ; still, as the information at present avail-
able appears to be of some economic value, it has seemed better to put it on
record at once than to wait until the observations are theoretically perfected.
The specimens, as I obtained them, consisted of the lower parts of the
stems and the attached larger roots of the plants. The latter and the basal,
and probably subterranean, portion of the stems showed conspicuous malform-
ations. At intervals along the course of the roots there were a series of rough
swellings where the bark no longer retained its smooth surface and grey colour,
but was evidently broken up and mixed with masses of soil. Towards the
origin of the roots the swelling became continuous and was very great, extend-
ing thence over the lower end of the stems and thence gradually thinning off
and disappearing a .few inches above. The texture of the swellings was friable,
and they evidently consisted of a mixture of dead disintegrating masses of
bark tissue, mixed with earth in varying proportions. On examining them
closely they presented a variegated appearance, due to the deep brown of the
dead bark tissues mingled with the brownish-grey soil. Here and there, too,
masses of a yellowish or rusty colour could be seen projecting from the general
surface, and on detaching portions of the surrounding material these were found
to be continuous with sheets and strands of similar colour diffused throughout
the looser superficial portions of the swelling. Similarly coloured areas were
also present in the deeper, denser parts of the bark and cambium, and, imme-
diately over the external surface of the wood, they were spread out so as in
many places to form an almost continuous thin layer. The colour here was in
some places much paler than more superficially, in certain cases being almost
white. On transverse section the wood was found to retain its hardness un-
altered and in most places appeared to be entirely unaffected. Here and there,
however, there were more or less wedge-shaped areas of grey discolouration,
with narrow, sinuous blackish margins separating them from the surrounding
normal pale yellow wood.
On detaching portions of the rusty material and putting them into water
Scientific Memoirs by
mould, a small pink Stilbum, and an inconspicuous mucorine fungus, also appear-
ed on some specimens of the bark, but neither with the same constancy nor in
such profusion as the mould described above. In no case was there any
attempt at the development of any Hymenomycete form of fructification.
In some cases a distinct growth of the rusty mycelium occurred during the
course of cultivation. The newly developed portions were characterised by
their frequent septation and by giving off numerous erect filaments densely
clothed with short branches tipped with numerous radiating processes. These
suggested sterigmata, but in no case could any development of conidia from
them be detected. Those portions of the mycelium where such growth occur-
red came to present a dusty, bright orange-coloured surface due to the tufts of
branched filaments.
Owing to the failure of the cultivations in affording conclusive results in
the form of fructification, it is as yet impossible to identify the nature of the
mycelium producing such destructive effects on the bark tissues, and without
experiments on artificial infection it is even uncertain whether the disease be
really essentially of fungal origin or whether the presence of the fungal ele-
ments is due to antecedent morbid conditions in the bark. There can be no
doubt as to the destructive effect of the mycelium on the host tissues; the only
doubt is whether the mycelium is capable of attacking perfectly healthy tissues.
That it can, and that it is therefore the essential primary cause of the disease, is
rendered highly probable by the general similarity in the distribution and charac-
ters of the morbid changes to those present in the case of the root-blight which
is so destructive in European coniferous forests and which has unequivocally
been proved to be due to the invasion of the tissues by the mycelium of
Agaricus melleus (Vahl.). It does not, however, appear probable that the latter
is the destructive agent here, for the mycelium in the tea-blight does not show
any tendency to assume a truly Rhizomorphic habit as that of Agaricus
melleus does, and if the mould appearing in the cultivations really hold an
organic relation to the mycelium, the latter cannot, of course, belong to any
Hymenomycete, but must be of Pyrenomycete nature. These are questions,
however, which call for further investigation, and all that can be safely stated at
present is that in this blight we have to deal with a disease in which fungal
mycelium plays an important, if not a primarily essential part, and that it is
possible that an important agency in securing the diffusion of the disease lies
in the conidia developed in such abundance on the morbid surfaces when these
are exposed to damp air.
Even with the confessedly imperfect data at present available, there can be
no doubt as to the practical measures which should be adopted with a view to
preventing the spread of the disease. All blighted plants should be at once
and completely removed. The ground where they occur should be carefully
and deeply dug over, and all portions of the roots as far as possible removed
Medical Officers of the Army of India.
11
and, together with the other parts of the plants, at once burned. An area in
which the blight has appeared should be left unoccupied for some time, and, if
possible, should be isolated by means of encircling it with a trench excavated to
a level below that to which the roots of the plants descend. By means of such
measures a limitation to the spread of the disease may be looked for, but with-
out isolation, and specially without careful removal and destruction of all
portions of morbid tissue, the disease, once established, may be expected to go
on continuously radiating over areas of wider and wider radius.
On the Results of Cultivations of Choleraic Comma-Bacilli in Earth,
in Cowdung, and in Human Excreta.
One of the great objections to accepting the view that the choleraic comma-
bacilli are really the essential cause of the disease is their apparent incapacity
for assuming a resting condition and their apparent general feebleness in the
struggle for existence. There were many phenomena on record regarding the
occurrence of outbreaks of cholera within areas where the disease is only an
occasional epidemic visitor which certainly appear to indicate that, if the
morbific agent be of an organised nature, the causative organism must be
capable of enormous multiplication under exposure to the prevailing local con-
ditions at certain times, and that at others it must be able to pass for prolonged
periods into a condition of dormancy. Within the endemic area, too, certain
phenomena in the seasonal cycle of prevalence are very hard to explain, save as
dependent on the alternation of periods of activity and of rest, or, at all events,
of periods during which the local conditions favour or repress the multiplication
of the exciting cause. During the course of the past season, a renewed attempt
has been made to determine how far the choleraic comma-bacilli are capable
of holding their own under external conditions such as those prevailing in
Calcutta, and in media to which they are specially likely to gain access in
large numbers under ordinary circumstances. The media to which choleraic
materials are specially likely to attain access in bulk are, of course, water and
soil of varying degrees of purity or organic contamination, and as it appears to
have been clearly shown that the commas rapidly disappear from water without
any attempt at the development of resting forms, attention was specially direct-
ed to the subject of their behaviour in soil. A series of experiments was, there-
fore, initiated in the middle of December, that is, just at the time at which the
minor of the two annual periods of minimum prevalence of cholera in Calcutta
normally begins to manifest itself, on the effects following the introduction of
large masses of choleraic commas into portions of common garden soil.
On the 16th of December two small glass beakers were filled with garden-
earth which had been thoroughly triturated with a certain amount of fresh, nor-
mal human excreta. The contents of five tube cultivations of cholera commas
12
Scientific Memoirs by
were then added to them, each receiving the contents of one and a half tubes of
common gelatine and one tube of agar-agar gelatine mixed with a certain amount
of freshly-sterilised salt solution and full of healthy commas. They were then
set aside under a bell-glass on a table in the laboratory. Both beakers were
allowed to remain thus until the 6th of January 1887. At this time the surface
of the soil in each was still moist and showed scattered patches of greyish
gelatinous matter, seemingly remains of the gelatine of the cultivations, together
with a few heads of Pilobolus crystallinus. One of them was now set on the
incubator to dry, and materials for cultivation were removed from the other.
These consisted of portions of the gelatinous matter from the surface. Some
of these were broken up in sterilised salt solution and used to start plate-cultiva-
tions, while others afforded material for preparations. The material was faintly
alkaline. It contained no active Schizomycetes, but numerous fungal cells and
encysted fæcal amœbæ, and innumerable still Schizomycete forms, especially in
the spore-condition. The plate-cultivations yielded an abundant crop of colonies
of various kinds of Schizomycetes, but, in spite of careful examination, no com-
mas could be detected.
On the 18th January another preparation and a plate-cultivation were made
from the same sample of earth. On this occasion the materials were taken from
about a quarter of an inch beneath the surface. No comma-bacilli were recognis-
able in the preparation. The plate-cultivation yielded a very abundant crop of
Schizomycete colonies after it had been for twelve hours in the incubator. It
had a peculiar, strong, bat-like odour, very unlike that characteristic of cultiva-
tions of the choleraic comma-bacilli. Two distinct forms of Bacilli were present
in large numbers, but not a trace of commas could be detected anywhere.
On the 1st March another plate-cultivation from the same soil was initiated.
The soil was now fairly dry, and after the material required for cultivation had
been removed, some freshly-boiled tap water was poured over it. The cultiva-
tion yielded numerous Schizomycete colonies. They all consisted of straight
Bacilli of various sizes, and no signs of commas could be detected anywhere.
Subsequent cultivations of the same sample of earth also failed to yield any
commas.
On the 18th March the beaker which had been in the incubator since the
6th January was examined. The earth was found to be perfectly dry. A small
portion was removed and mixed with freshly-sterilised salt solution to form the
basis of a plate-cultivation, a large quantity of freshly-boiled distilled water was
then poured into the beaker, so as to flood the soil, and the beaker was replaced
in the incubator. On the following day the plate-cultivation showed numerous
colonies, consisting of two forms of straight Bacilli, but no commas could be
found. On the 21st March the surface water had disappeared from the soil in
the beaker. Materials for a plate-cultivation were removed, and the earth was
again flooded with freshly-boiled distilled water. On the following day the plate-
Medical Officers of the Army of India. 1 5
A mass of it was set in a sterilised watch-glass in a moist chamber, and a
plate-cultivation was started at the same time. Numerous colonies appeared
in the latter. They were of small size and yellowish colour, and were accom
-panied by a faint odour quite distinct from that present in cultivations of cho
-leraic commas. They all appeared to be alike and composed of very short,
thick, almost micrococcoid Bacilli. On the 31st March the cowdung was
inoculated with a mass of agar-agar full of commas. Numerous plate-cultiva
-tions were carried out from time to time up to the 20th April, but in no case
did any commas make their appearance. Numerous colonies developed in all
cases, but these never contained commas. The majority of them consisted of
short, thick Bacilli, which, when in mass, had a peculiar greenish-yellow colour,
and which imparted an odour to the cultivations very similar to that of cultiva
-tion of commas. Repeated cultivations showed clearly that they bred perfectly
true under conditions most favourable to the development of commas, and
that they, therefore, were specifically distinct from the latter. On the 20th April
a plate-cultivation was inoculated from the portion of agar-agar introduced into
the dung on the 31st March, and which was now, curiously enough, absolute
-ly crowded with the myceleum and zygospores, or, perhaps mote correctly,
oospores, of a small mucorine fungus, apparently parasitic on Pilobolus crystalli
-nus, which at this comparatively late period had begun to appear in abundance
on the surface. There were no recognisable commas in the agar-agar, and the
cultivation failed to produce anything save a few minute colonies of straight
Bacilli.
The above data appear to indicate that cowdung, apart from the organisms
normally present in it and destroyed by boiling, constitutes a highly favourable
medium for the development of choleraic commas, but that in its normal
state the development is either entirely repressed or very much enfeebled, due to
the influence exerted by other fungal and Schizomycete organisms. They
also clearly show that in this medium also the commas have no capacity for
the assumption of a resting condition.
The first set of experiments had appeared to show that human excreta did
not constitute a favourable medium for the growth of choleraic comma-bacilli,
but it appeared desirable to endeavour to ascertain how far the results then
attained were not due to the acid fermentation normally occurring in such
materials in connection with the abundant development of fungi usually occurring
in them during the earlier stages of decomposition. Some normal, fresh, almost
neutral human fæces were accordingly diluted with distilled water and strongly
boiled for some time, and a portion of the material was then set in a sterilised
watch-glass in a moist chamber. On the following day the re-action was
distinctly and permanently alkaline. A portion of agar-agar, full of healthy
choleraic commas, was now introduced. Forty-eight hours later the material
had a peculiar mawkish smell and was alkaline in re-action. From this, time
16
Scientific Memoirs by Medical Officers of the Army of India.
onwards repeated plate-cultivations were inoculated from it, but even when
the inoculated materials included portions of the agar-agar, they yielded no
commas, although producing an abundance of various other forms of Schizo
-mycetes. It would appear from this that human fæces are even less favourable
to the growth of commas than cowdung, the temporary repression in the growth
of other organisms consequent on boiling of the medium failing to produce
the effect that it does in the case of cowdung. All the data seem to
indicate that the choleraic comma-bacilli are, under ordinary circumstances
extremely feeble in the struggle for existence. In media, such as fresh cow
-dung appears to be, which in themselves afford everything necessary to their
continued vitality and multiplication, the presence of other organisms normally
present in the medium is sufficient to repress or absolutely suppress further
development, and in other media, such as human fæecal matter, even the aid
of artificial measures calculated to place them at an advantage in the struggle
are insufficient to be of any avail in securing their continued existence. Not
only are they weak in the active struggle for existence however, but they
are also apparently incapable of tiding over periods during which the media are
in any way unfavourable by assuming a resting state. It is, no doubt, true that
in many sterilised media in which they are not exposed to competition with
other organisms they are capable of enormous and rapid multiplication, but
under ordinary circumstances they do not gain access to sterilised media, but to
media already occupied by their normal inhabitants. If the choleraic commas
really be the essential cause of the disease, then the facts would lead us
to regard their agency in the production of epidemics as entirely subordinate to
the influence of local conditions securing the presence of media of peculiar
quality favouring their continued development. Normal water, soil, and excreta,
or the normal media to which choleraic commas are specially liable to gain access,
do not seem to provide against their speedy extinction, so that it can only
be where some very special medium is present, or where the common media
deviate from their normal standard, that there can be sufficient provision to
secure the multiplication and continued persistence of the commas to such
an extent as to accord with many of the phenomena of epidemic diffusion
of the disease.
CALCUTTA,
The 15th May 1887.