123 
suspicion. On the other hand, in what may be termed the 
hot weather condition of wells and springs, bacillus cloace 
is nearly always the only organism present, and, knowing 
as we do, that this bacillus is gifted with great longevity in 
soil, no very great significance can apply to the presence of 
these organisms, provided that the number is not too large. 
We can only therefore advise as follows: (1) look with grave 
suspicion on all fecal bacilli in well water ; (2) be guided more 
by the quantity of fecal organisms per c.c. than by the kind 
of organisms ; and (3) on no account ever give an opinion 
without an inspection of, or a report on the surroundings by a 
Medical Officer. It should be borne in mind that extremely 
valuable information, as to the possibility of the entrance 
of the fecal contamination, can be obtained by taking samples 
from the wells shortly after heavy rain ; and, in case the well 
water is the sole drinking supply of a community, such as a 
jail or school, a series of analyses of samples taken under 
different meteorological conditions should always be made 
in doubtful cases, before giving a definite opinion. 
Of course, these remarks apply mainly to surface wells. 
Deep wells are comparatively rare in India. There is no 
doubt that the surface well is an extremely bad source of 
water-supply, and that it is probably responsible for a large 
proportion of the water-borne disease in this country. 
Unfortunately in many places it is the only supply available. 
This brings us back to the question already referred to, 
viz., when may a badly polluted water be considered to have 
passed ‘‘ the safety change’’? The question is obviously one 
of very great importance, and one that is surrounded by very 
many difficulties. In the first place, it assumes a fact which 
is probably correct, viz., that all the important pathogenic 
intestinal organisms are in the most uncongenial environment 
when placed in water, and they die out with great rapidity 
when exposed to the action of sun, etc. For the truth of this 
statement there is now a considerable amount of evidence. 
The work of Houston on the viability of cholera and enteric 
organisms in water kept in a laboratory confirms this opinion. 
Horrock’s investigations on the symbiosis of Eberth’s bacillus 
and coli communis also supports the contention. It should 
