18
account they can give of the matter is that about forty years ago the villages on.
the slopes had to he abandoned on account of the " wait hawa," ( literally the
' mal-aria ') of the mountain. Even down at the water-side the influence of the
proximity of the hill is seen in the spleen rates found in the villages. On the
east of the range, where the villages are entirely shut off from sea-hreezes, the
spleen rates are among the highest possible ; 82 per cent, at Kausa, and 93 per
cent, at Mumbra.
An attempt that was made ten years ago to solve the problem of house
accommodation at Thána by building bungalows for Government officers on
one of the northern slopes of the Parsik range, was a complete failure. The
bungalows proved as malarious as the villages of the Parsik range had been, and
residence in them has had to be given up entirely.
The case of the island of Trombay, forming the south-east corner of
Salsette, may next be studied, With its hill of trap-rock, rising to 1,001 feet,
wbose sides, as they slope down to the sea, are covered with the soil which is a
product of the disintegration of the trap, and the edging of salty alluvium along
its shores, on which the abundant growth of trees and grass conies to the usual
abrupt conclusion, the island of Trombay forms an excellent miniature edition
of Salsette. No detailed demonstration of the relation of Malaria to the hill is •
required ; the figures show the closeness of that relationship so well themselves.
Villages close to the base of the hill or on the slopes of one of its spurs, have a
Spleen Rate of over 50 per cent., which rapidly gives way to smaller rates, ranging
from 10 per cent, upwards, at a little distance from the hill. The hamlst of Oharai,
at the cross-roads, is far enough away to have only 7 per cent. Further north.,
Chembur, which is still nearer the edge of the tree and grass-covered area, has
but 4r2 per cent. But what will be found most significant is that the Spleen
Rate of the children of the Mahárs and Bhangis of the Bombay Municipal Re-
fuse Depot, a little further North still, is nil.
People will not, of themselves, build their villages right out in the open,
away from, the shade of trees, nor will any one build villas or bungalows either.
This is only natural, and it must be accepted as an axiom in considering what
advice is worthwhile giving. But the one drawback of it, in the casa of a
malarious tract of country, is well seen here, where the Mahárs and Bhangis of
the Refuse Depot are not only better off in respect of Malaria than the well-to-do
artizans of Chembur, but have absolutely no Spleen Rate at all. The reason
for it consists in the fact that they cannot choose their place to live in them-
selves. Their occupation necessitates their living out on the salty alluvium,
where there are no trees, and the shortest of grass will hardly grow. Nobody else
would live in such a place, and the result is that no other village in the whole
of the East of Salsette is like theirs : it is the only one that does not have Mala-
ria in it.
The effect of the sea-breezes is well seen in the case of the village of
Trombay itself, which has a Spleen Rate of only 1.3 per cent., in marked
contrast to the neighbouring villages inland.
If a general view is taken of the island of Salsette it will be seen that
the central hills are surrounded with a ring of villages all having a Spleen Rate
of anything between 60 per cent, and 95 per cent. Yeur is the village at the
highest altitude that was visited : its rate is 94 per cent. It is very noticeable
LOW, as one passes outwards from the hills to the sea, the Spleen Rate decreases s
even where it is only a creek that represents the sea, as in the case of the eastern
side of Salsette, while on the western side the villages most completety exposed
10 the sea-breezes have no Spleen Rate at all. The gradation is in some parts
very noticeable ; indeed one might in some parts draw lines connecting figures
of the same colour and find that they ran parallel with the direction of the range
and of the coast-line. Corresponding with the isobars or isotherms on a meteo-
rological chart, these lines of approximately equal spleen intensity might be
called " isosplens ". Starting near Thána for example, one such isosplen (red)
would run from Navpada southwards through Mulund, Nána, Bhatti, Kanjur,
Hariáli and Vikhroli. Another (brown), further from the hills and nearer the
creek, would run from Gavhán through Navghar and Bhandup. Another