48
•
quarter,. iu all the water-supplies, there was a great falling off in the number of
-
cloacæ, accompanied by a decline of its numbers in cowdung and. fœces. Another
striking example is the rapid. increase in the prevalence of coscoroba in both human.
fœces, cowdung and the water samples contemporaneously (vide the natural waters,
table XIII (a), (b), (c), Chapter XIII). The third and perhaps the most important
example is furnished by the October results in Chapter V.
In order to explain these parallel variations we have come face to face with the
question, is it the flora of the fœces which determines the organisms in the water ?
or is the reverse true, and have the organisms present in the water any influence on
the contents of the fœces ? There can be little doubt that under some circumstances
the first of these questions may be answered in the affirmative. Although we are at
present entirely in the dark as to what caused the rare organisms to appear in the
discharges of man and animals in the month of October, there can be no reasonable
doubt that the monsoon conditions, existing at the time, washed them in the water-
supplies. This may also explain the coscoroba prevalence in December, January
and February, for rains had been more or less common in November, December and the
first week in January. But it certainly cannot explain the relation between the
.prevalence of cloacm in both water and fœces in August for, firstly, during the
months of July and August there was practically no rain; and secondly, we know
what natural influences caused cloacæ to be so numerous in the water at this.
time, viz., that the organisms is one of the last to survive in a stored water- (vide
Chapter IX).
Therefore, as it is certain that the fœces did not directly contaminate the various
water-supplies at this time, it is all the more remarkable that the prevailing bacteria
present in water and fœces should be identical, and it suggests that a reverse action is
taking place, namely, that the organisms prevalent in the water-supplies are influen-
cing the bacteriological contents of the intestines. At one time in the course of our
investigations we were somewhat inclined to this view. , The experiment given by
MacConkey (Journal of Hygiene, 1905), where he inoculated the food of a cat with
an outside organism, and recovered it in the fœces 24 hours afterwards, seemed to
support this theory. In order to test the truth or otherwise of this surmise, certain
experiments were made in the King Institute, to see if it were possible to demonstrate
any relation between the organisms present in an artificially contaminated drinking
water-supply, and the fœces of animals drinking such water. Altogether about eight
calves were selected. They were given King Institute well water morning and
evening ; but to each bucket, a large number of one of the following organisms were-
added—oxytocus perniciosus, organism No. 97, cloacæ, lactis ærogenes and coli
communis. At periods varying from one day to a week (the feeding experiments
being kept on all this time), the fœces were examined ; in no case were we ever able
to recover in the fœces of the calves the organism that was present in the drinking
water. Great care was taken so as not to alter the daily routine of the animals' life,
no drinking supply, other than the artificially contaminated water, was allowed. Very
large quantities of the organisms were given. It is true the bacilli used were derived
from laboratory cultures, but this would not be likely to vitiate the results. The
negative results obtained these experiments would appear to show, that, the organisms
taken in drinking water produced no alteration in the intestinal flora.
There is also a further point which may be mentioned. Throughout the months
of October, November and December, lactis ærogenes was an extraordinarily common
organism in all the water-supplies. Yet there was no correspondingly increased
prevalence of this organism in the samples of fœces examined at that time of year.
Consequently, one is forced to the conclusion, that, the presence contemporaneously of
bacillus cloacæ in both fœces and water-supplies is not yet satisfactorily explained.
It will be very interesting to note whether a similar state of affairs recurs at the same
pe r i od t hi s ye a r ; pe r s ona l l y we t h i n k i t wi l l , a s t h e r e a r e a l r e a d y s o me i n d i c a t i o n s o f
its approach. It will be noticed that we are still without any trace of explanation,
as to what conditions bring about these changes in the bacteriological contents of the
intestinal canal of man and animals, and at this time we are not prepared to make any
suggestions. That such influences exist, and that they are active over a very wide
area is certain, as shown by the facts reported in Chapter V.