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Bacillus Pneumoniœ and Rhinoscleroma No. 68.—This organism is usually found
in small numbers in human fæces, cowdung and water-supplies. In point of power to
resist sunlight it falls into the large class 2.
Bacillus No. 67.—Is common in samples of fœes of both human beings and
cattle. It is also met with fairly commonly in water-supplies. In point of resistance
to the action of sunlight it belongs to class II.
Bacillus No. 69.—This has never been isolated from fœes by us. It was
found in water-supplies in October—vide the remarks about organism No. 10.
Bacillus No. 70.—Was found both in fœes of man and animals. The same
remarks as made about organism No. 10 apply to this bacterium.
Neapolitans No. 72 and Bacillus No. 74.—This is a fairly common organism
and remarkably constant at all times of the year and in all samples of human fœces
and cowdung. It is also constantly prevalent in water-supplies. About its resistibility
it certainly belongs to the large class No. 2.
Bacillus Nos. 73 and 75.---This is an organism that has been isolated.from cow-
dung and human fœces and is fairly prevalent in water-supplies. It has also been
isolated from the trenching ground earth a considerable time after pollution had taken
place. It is undoubtedly a resistant organism, but further work is necessary as to
which class it should go into. At present it is temporarily placed into class III
amongst the resistant organisms. The fact that it is somewhat rare renders it difficult
to put into its proper place without more work.
Bacillus Nos. 97, 98 and 99.—These have not, up to the present, been met
with by us.
Bacillus Nos. 100 and 101.—This is an organism about which we were at first
inclined to be sceptical in spite of the fact that several bacteriologists have claimed
to have isolated it. It is nearly always found in mixtures with lactis æ rogenes, and.
the difference between these two bacteria is mainly the presence or absence of Voges
and Proskauer's reaction. Thanks however to the improved methods of carrying out
the tests, we have come to the conclusion that there is no doubt that it is a different
organism. It is met with in the fœces of both man and cattle, but more frequently
in the latter. It is frequently met with in water-supplies as the figures show. It
is placed. in class II, but possesses very considerable power of resistance to the
action of sunlight.
Lactis Ærogenes etc.—This organism is an extremely common one, under certain
conditions, in water-supplies. It is extraordinary that it is not more commonly met
with in the fœces of man and animals; in these it is rather rare on the whole. The
circumstances under which it is extremely common in water-supplies are as follows :-
After heavy rain has occurred washing the pollution off the land into water courses
and lakes, and. some time having elapsed. for the subsidence of silt and the sunning of
t he wat er , l act i s ær ogenes i s al ways f ound. i n l ar ge number s. Consequent l y i t i s mor e
common in lakes than in rivers. The results given in Chapter IX confirm this opinion,
and also suggest that, it is in the middle layers of a deep lake, in which these organisms
are usually to be found. It was is not found in any large numbers in our work on
polluted earth. Its position as regards its power of resistance to sunlight is, we consider,
strictly half way between that of the susceptible and the very resistant organisms.
When these latter are present in large numbers lactis ærogenes is rare. Similarly it
is not common in very newly polluted. water, but makes its appearance after storage
and. sunning. When present in large numbers it is an indication that a fair amount
of purification has taken place—vide Chapters IX and X.
Coscoroba or No. 106.—This organism, next to grunthal group, has been found
by us to be the commonest in the fœces of man and. domestic animals. As the
analyses show its frequency varies greatly at different times of the year. It is very
common in water, particularly in such. water as we are certain are derived from washing
the surface of a polluted ground. It has not been found common in the samples of
earth we have taken. It belongs to class II in point of power of
r e s i s t a n c e .
Cloacœ—This organism is one of the most interesting of the whole series. It
is never very common in human fœces and is frequently absent from them. It is
occasionally extraordinarily common in the fœces of cattle, but is occasionally,