55
SAMPLE IX.—OLD OoTACAMUND CISTERN.
N u m b e r .
I a c t o s e .
S a c c h a r o s e .
D u l c i t e . A d o n i t e . I n u l i n .
V o g e s a n d P r o e k .
I n d o l . M o t i l i t y .
G r o u p .
Name of Bacilli.
Group and
Remarks.
Total colonies per cc. on agar at 37°—150.
Bile salt lactose, medium.
+
—
1 tube of 20 ce. o f w a t e r t a k e n .
. . 1
No lactose fermenters could be isolated.
2 t u b e s of 10 cc.
" .. .. 1
1
3
"
5 c c
„
.. . .
. .
3
3 „ 1 cc. „
. . . .
. . 3
3 „ -1 cc. „
. .
. .
. .
3
3 "
- 0 /
c c . "
..
..
. .
3
No fœcal bacilli in 60 co.
No vibrios in 100 cc.
REPORT.
The analyses of the samples taken this quarter give the same sort of conflicting results that have been
noticed on previous occasions. The water of the Old Ootacamund Cistern heads the list on this occasion as
regards purity, and both bacteriologically and chemically is of exceptional quality. Next in order we have the
waters of the Upper Dodabetta and Kodappamund Reservoirs. In both respects these two waters are also
exceedingly satisfactory, and except by comparison with the previous water there is nothing to take exception
to. Of late it has been unusual for the water of the Marlimund Lake to be anything but last on the list, but
this time it ranks along with the water of the Lower Dodabetta Reservoir as regards its content of fœcal
germs, while it shows a much lower total count and chemically is also a better water. With one lactose
fermenter to the cc. and only the resistant species represented these water can, from the bacteriological point
of view, be regarded as moderately satisfactory. Chemically they are not so good, both showing too high
figures for albuminoid nitrogen. This is the first occasion that the water of the Kodappamund Lake gives a
f i g u r e i n t h e s e c o n d p l a c e o f d e c i m a l s f o r a l b u m i n o i d n i t r o g e n , a n d t h e r a t i o o f t h i s f i g u r e t o o x y g e n a b s o r b e d
is also very high. This points to an animal origin for the organic matter present in the water, whereas that
in the Marlimund water is probably of vegetable origin. The water of the Tiger Hill Reservoir contains too
many fœcal germs, but they are all of one very resistant species, a state of affairs characteristic of a well
- s u n n e d l a k e w a t e r . H e r e a g a i n t h e f i g u r e f o r a l b u m i n o i d n i t r o g e n i s t o o h i g h a n d t h e o r g a n i c m a t t e r p r e s e n t
is, in pat at least, of animal origin. On this occasion the Marlimund pipe line maintains its reputation as a
purifying agent, the water drawn from it being as pure bacteriologically as the water of the Old Ootacamund
Cistern which, as above noted, is very pure indeed. Of the pipe line waters the Tiger Hill comes next and the
water has undergone a very remarkable change. The fœcal germs have been reduced at least six hundred fold,
and when we remember that only the most resistant species were present in the lake water, this change is very
striking. The total count has however gone up enormously and this would seem to point to the presence of
silt in the pipes. The water from the Dodabetta pipe line is very much what we would expect from a mixture
of the waters from the two reservoirs. Some sedimentation has probably taken place, but otherwise there is
no change.