KING INSTITUTE, GUINDY, FOR 1927-28
along the enbankment must be constructed leading to the present fish pond, which
when provided with sluice gates and tidal locks can be either drained completely
or flooded with sea-water as desired taking advantage of the five feet range of
ordinary spring tides. A sufficient number of cross drains leading into this main
drain will keep the marshy land dry and these can be kept safe by weekly oil
treatment.
(g) While these measures are being undertaken, systematic oiling of all
the breeding places must be commenced at once to keep down the mosquito
production. Provision must be made for an adequate staff for periodically
examining and regularly oiling all the areas. To leave them to the existing
staff of Sanitary Inspectors will not do. A separate anti-malarial staff of at least
one Sanitary Inspector and four coolies will be necessary, and during the rainy
months an additional temporary staff will be required to fill up a number of small
puddles and conserve the edges of drains, the sides of the tanks, etc., to remove
algae, and to prepare the places for oiling generally. A mixture of crude oil
and castor oil (in the proportion of one ounce of the latter to a gallon) sprayed
from a hand spraying machine has been found to be satisfactory.
(h) Three authorities are now interested in the anti-malarial operation in
Vizagapatam, viz., the municipality, the harbour and the railway authorities. It
is greatly desirable, they should co-operate and their efforts be co-ordinated by a
single board whereon all the three can be represented.
9. I am greatly indebted to Dr. C. Balakrishna Chetti, M.B., B.S., D.P.H.,
Health Officer, Vizagapatam Municipality who detailed one of his Sanitary
Inspectors to assist me in the investigation and himself accompanied me on
several occasions when collecting adult mosquitoes from the houses ; and to
Dr. C. Ramamurt i , M. B. , B. S. , B. S. SC. , Professor of Hygi ene, Vi zagapat am Medi cal
College, who estimated the salt contents of some of the specimens of water
for me.
APPENDIX.
Well
num-
ber.
p. H.
Electrical
conductivity
in 1/1000000
ohms.
C X 10.
Species of anopheles breeding.
Well
num-
ber.
p H.
Electrica1
conductivity
in 1/1000000
ohms.
C X 10.
S p e c i e s o f a n o p h e l e s
b r e e d i n g .
1
8.0
2,472
A. vagus.
31
8.0
3,254
A. stephensi.
2
8 . 0
3,531
A. culicifacies.
32
8 0
3,862
A. culicifacies.
A. stephensi.
3 7
. . .
. . .
A. stephensi.
3
8.0
4,119
A. culicifacies.
42
8.0
988
A. culicifacies.
8
8.0
2,747
Do.
53
7.0
1 , 0 7 5
Do.
9
8.0
1,647
Do.
58
8.0
1,647
Do.
10
7.8
. . .
Do.
59
. . .
. . .
Do.
12
8.0
1,901
Do.
60
. . .
. . .
Do.
13
. . .
. . .
A. stephensi.
72
7.4
727
Do.
14
. . .
. . .
Do.
74
7.2
727
D o .
16
8.0
2,472
Do.
92
8.0
1,373
Do.
17
8.0
1,901
A .culicifacies.
96
8.0
727
Do.
19
8.0
3,987
Do.
102
7.6
727
Do.
20
8.9
3,531
A. stephensi.
116
8.0
1,801
Do.
21
8.0
3,434
A. culicifacies.
119
7.0
1,075
Do.
26
8.0
4,752
A. stephensi.
137
7.2
1,646
Do.
27
8.0
1,454
A. subpictus.
138
7.4
1,647
Do.
28
7.6
2,574
A. culicifacies.
NOTE.—Wells numbered according to the April list.
A REPORT ON SEWAGE ANALYSES AND EXPERIMENTS
BY ME,. N. SWAMINATHAN.
( a ) Experiment at the Engineering College, Guindy, 1926-27.
The sewage disposal works at the Engineering College, Guindy, consist of an
open septic tank, a closed septic tank, a Hydrolytic Emscher or Imhoff tank
and a continuous bacterial "filter."
41
6