iii
Nature of vegeta-
tion, trees, scrub
junqle, and the like.
Prickly-pear abounds in waste places. Not many trees, and no low
jungle.
10. Geology.
Nature of under-
lying rock.
The two conical hills which lie between Palaverarn and the sea are
outliers of the Chingleput hills. They are composed of a hard, small-
grained gniess, rather dark in colour, and decomposing into a reddish
surface soil. The stone is quarried, to some extent, for road-making
and building purposes. The same rock underlies also the locality on
which the cantonment is built. To the east, where the houses of
the European Officials are built, the houses actually rest on a foun-
dation of rock, but the parade ground and site of the European
barracks consist of a reddish clay soil, beneath which is found, in
patches, sedimentary laterite. The laterite deposit in the neighbour-
hood of Palaveram is nowhere of any great thickness. In some
places in the river valley it rests on clay, and in other parts it is close
to the underlying rock. The surface soil increases in depth towards
the river bank, and the site occupied by the European barracks and
family-quarters has some ten or twelve feet of clayey, or lateritic,
soil intervening between the surface and underlying rock.
11. Nature of soil
and sub-soil.
The surface soil is evidently an alluvial deposit, with a preponderance of
reddish clay. It varies in depth from a few inches, near the base of the
hills, to ten or twelve feet near the river. The sub-soil is the gravelly
form of laterite, cemented together, apparently, by a silicate of iron.
(b.) Porosity
In the upper part of the cantonment, owing to the slope of the ground,
water runs off freely. Near the river the soil is deeper, and not
very porous.
(c.) Absorptive
properties.
(d.) Chemical con-
stituents.
(e.) Air in sub-
soil.
Undetermined.
Do.
Do.
12. Malarial dis-
eases when preva-
lent ?
The Native population of Palaveram do not appear to suffer from
malarious affections to any extent. Nor do the European troops.
The following figures show the proportion of admissions and deaths
from malarious fevers in the Military force stationed here for the five
years ending 1870.
'European, Troops.
Years.
1866
1867
1868
1869
1870
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
Mean Strength
200
254
309
353
207
Intermittant Fever.
A.
14
3
...
...
11
D.
...
... ...
...
...
Remittant Fever.
A.
...
1
...
...
...
D.
...
...
...
...
...
Continued Fever.
A.
8
17
19
8
7
D.
...
...
...
...
...
Typhus Fever.
A
...
...
...
...
...
D.
...
...
...
...
...
Typhoid Fever.
A.
...
...
...
...
...
D.
...
...
...
...
...
Total
A.
22
21
19
8
18
D.
...
...
...
...
...
RATIO PER 1,000 OF MEAN STRENGTH.
Intermittant Fever.
A.
70.0
11.8
...
...
53.1
D.
...
...
...
...
...
Remittant Fever.
A.
...
3-9
...
...
...
D.
...
...
...
...
...
Continued Fever.
A.
40 0
66.9
61.4
31.6
33 8
D.
...
...
...
...
...
Typhus Fever.
A.
...
...
...
...
...
Native Troops.
1866
1867
1868
1869
1870
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
176
140
174
115
133
46
31
59
28
40
1
1
1
...
1
1
1
3
1
...
l
...
...
...
...
...
...
...
...
3
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
47
32
62
29
43
2
1
1
...
1
261.4
221.4
339.0
243.4
300.7
5.6
7.1
5.7
...
7.5
5.6
7.1
17.2
8.7
...
5.6
...
...
...
...
...
...
...
...
22.5
...
...
...
...
...
...
...
...
...
...
D.
...
...
...
...
...
Typhoid Fever.
A.
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
D.
...
...
...
...
...
Total.
A.
110.0
82.6
61.4
31.6
86.9
D.
...
...
...
...
...
...
...
...
...
...
267.04
228.5
350.3
252.1
323.3
11.7
7.3
5.1
...
7.5