12
REPORT OF THE KING INSTITUTE, GUINDY
(F) WORK FOR THE WATER AND SEWAGE PURIFICATION COMMITTEE.
1. Water experiments at Guindy.—These experiments on water purification
with a submerged and non-submerged coarse sand filter were continued.
Period VII—April to July 1927.—The non-submerged percolating filter
yielded definitely better results during this period than the submerged filter.
About the middle of June, however, probably as a result of the rains that fell
(between 20th and 29th) both the filters showed deterioration, the percolating
filter still being the better of the two.
Period VIII—October 1927 to March 1928.—The next set of experiments com
- menced only in October owing to the very low condition of the river in August
and September. Both filters were started on 7th October 1927 at 4" and the rate
was increased to 6" on 22nd October 1927. Sulphuretted hydrogen appeared in
the submerged filter towards the end of March, while the percolating filter did not
show any. Although no definite superiority as regards bacterial purification can
be claimed for either, the advantage seemed to lie with the percolating filter as
regards the reduction of organic matter. The experiments are still in progress.
2. Water experiments at Kilpauk.—In pursuance of the orders conveyed in
G.O. No. 718, P.H., dated 11th April 1927, experiments on water purification were
started in October 1927 at Kilpauk and have been in progress since then. As at
Guindy, the plant is under the control of the Sanitary Engineer to Government.
The enormous increase in the number of samples examined (vide Table XIII) was
mainly due to the very large number of samples (3,336) that were dealt with at
Kilpauk. Most of these were examined only for lactose fermenters and the
amount of oxygen absorbed.
Since a first report on the results of these experiments from October 1927 to
the end of March 1928 has already been submitted to Government there is no
need to review the work here.
3. Sewage.—Mr. N. Swaminathan continued to work as Sewage Analyst and
at times helped with the many water samples analysed at Kilpauk.
Analyses were made of samples from sewage installations in Madras, Madura
and Kodaikānal. Brief details are given in Table XVII. The full analyses will
be published in the Scientific supplement. Briefly we may say that only the
following three plants were working satisfactorily :—The hydrolytic " tank at
the Binny Mills in the Waterton Estate, Madras, the septic tanks at Pasumalai
and at Evelyn Gardens Kochadai, Madura. Samples of the Cooum and Buck
- ingham Canal showed that the most heavily polluted parts were the Cooum at
Hutton's Bridge, and the Buckingham Canal near the Moore Market and at
Elephant Gate where nightsoil appears to be emptied into the canal.
(G) OTHER RESEARCHES AND REPORTS.
Government in their G.O. Mis. No. 640, P.H., dated 20th March 1928, sanc
-tioned reports of Investigation Units of the Institute being published separately
as a supplement to the annual report. Accordingly such a supplement will be
published this year for the first time.
1. A second malaria survey of Vizagapatam Municipality. —This was made by
Assistant Surgeon K. V. Venkataraman in August and September 1927. The
report will be published in the supplement.
2. A malaria survey of Chittoor.— This was made by Assistant Surgeon K.
Padmanabha Menon in February and March 1928 and the report will be published
in the supplement.
3. Plague in Kumbak ōnam.—A disease appearing to be plague was reported as
occurring in squirrels in Kumbakō nam. It was investigated by Sub-Assistant
Surgeon K. S. Ranganathan: A report was submitted to Government. Since a
paper on this subject has been accepted by the " Indian Medical Gazette " for
publication it will not be included in the supplement.