NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
91
The area over Bhera in' this year is also an area of heavy precipitation.
Enough has been said to show that in 1908 there was a very close relation
between rainfall and epidemic conditions. But we must not be led to the con-
clusion that the epidemic areas were always those which received the heaviest
rainfall. Such an, idea can be seen to be inadequate by referring to the figures
for Gurgaon and Delhi. According to rainfall Delhi district (34 inches) should have
been the most affected, whereas in reality the most affected was Gurgaon (28.9).
Or taking another example Sialkot should have been as severely affected as
Gujrat.
If we examine the eastern and western edge of the heavy rainfall area (30-
inch line) and of the epidemic (epidemic figure over 5), we shall see that whilst
epidemic conditions often extend considerably further in a south-west direction
than the rainfall would lead us to expect, they very seldom extend at all to the
north-east, and are apt in this situation to fail to extend to the rainfall limit.
The only reasonable explanation of this phenomenon is that the effects we see
are those of " floods," a conclusion to which further considerations will also take
us.
Departure of Rainfall from Normal.
The greatest departure from normal in the total monsoon rainfall was over
the district of Montgomery (19.01). Following this are the figures for the
district of Gujrat (18.5), Jhang (17.48), Sialkot (16.37) and Ferozepore (16.28).
Jhelum and Amritsar show 15.85 and 15.54, respectively. There is thus a relation
between the excess over normal and epidemic conditions. But this is by no means
absolute. Montgomery behaved in regard to epidemic conditions more in accord-
ance with its total rainfall than with the excess over normal. Sialkot similarly,
though it had a high excess over normal, was not seriously affected by the
epidemic.
Total Monthly Rainfall and Monthly Excess over Normal Rainfall.
In the case of Amritsar the excess of 15.54 was almost entirely due to rain
falling in one month, the total rain in this month (August) being 21.6 inches and
the excess being 14.0 inches over the normal. Palwal similarly had 20.85 inches
in one month. But Sialkot also received over 20 inches in August without be-
coming affected, though it is noticeable in this case that, of the excess of 16.37 in
the total only 8.72 is made up by the August rainfall, the remainder being dis-
tributed over July and September. On the whole if we take those districts which
have received over 10 inches excess rain in a single month, we shall in many
cases arrive at those which suffered most in the epidemic, but we shall include
Ferozepore and only just include Gujrat and generally speaking we are no nearer
N2
92
the solution of our problem than we were when considering total monsoon rain-
fall.
Rate and Season of Precipitation.
The monthly rainfall at Amritsar, Palwal, Bhera, Gujrat and Delhi are given
in the following table :—
June.
July.
August.
September.
Total.
Amritsar .
.
.
.
.
0.35
9.70
21.60
3.35
35.00
Palwal
.
.
.
.
.
0.92
11.20
20.85
0.65
33.62
Bhera
.
.
.
.
.
0.93
5.46
6.41
14.60
27.40
Gujrat
.
.
.
.
.
0.26
8.72
17.31
10.57
36.86
Delhi .
.
.
.
.
.
0.15
14.10
19.85
0.61
34.71
It will be seen that at Palwal and Amritsar the heaviest rain fell in August and
at Palwal practically none at all in September. At Bhera and Jhelum the heavy
rain was in September, the excess in July and August being slight.
Any very subtle relation to the exact period of the monsoon when excessive
rain falls is therefore not probable.
The intervals at which rain fell at a number of places were closely studied, but
the only relation which seemed to hold between the character of the rainfall and
the epidemic conditions was the heaviness of the falls.
Flooding.
An examination of the recorded rainfall in 1908 monsoon shows us therefore
a close connection between the total fall and epidemic conditions. As we proceed
to more detail characters the connection is less obvious ; in fact endeavouring
to explain the relation of rainfall to epidemic disease, I have arrived after much
study at no satisfactory conclusions. But when the rainfall is considered in
relation to flooding a great deal of the difficulty disappears.
Ferozepore, we shall see from the table, received a total monsoon rainfall of
27.74 inches and an excess of 16.28 over the normal. We might expect this
district to show much higher figures than it has done. The escape of the upper
portion of the Sutlej valley in this district is particularly noticeable. But we find
that Ludhiana and Jullunder, the districts higher up the riverain, have received
only 3.42 and 3.80 excess, respectively. The chief effects are seen lower down the
river at Fazilka and Jalalabad where flooding did as a matter of fact occur. The
escape of Sialkot is also noticeable and is difficult to explain unless we consider the
possibility that for some reason the district was not seriously affected by floods.
93
I I . — R A I N F A L L I N P R E V I O U S Y E A R S .
In 1908 it will be observed that the line representing the extension westwards
of 10 inches monsoon rain is close to the western border of the Punjab and that
the area receiving 20 inches of rain and over extends over nearly the whole of the
central third of the Province.
1907-1904.
In 1904 the line indicating the extension of 10 inches of rain and over scarcely
covers a third of the Punjab, whilst a rainfall of over 20 inches is restricted to a
minute portion of the submontane tract. In this year there are no thanas show-
ing epidemic prevalence.
In 1906 the extension of the 10-inch line is about the same, but the 20-inch
line includes Sialkot, Gurdaspur, Hoshiapur, Umballa and the districts lying along
the Jumna. The districts receiving 30 inches are restricted to parts of Gurdaspur
and Umballa. In this year there are a few small spots of epidemic mortality
within or just beyond the 30-inch line (Machawara).
In 1905 and 1904 the rainfall is very restricted. No thanas showed epidemic
prevalence.
In 1903 the 20-inch line extended in the north as far westwards as the Shahpur
district. There were some small epidemic foci, one being at Bhera.
In 1902 rainfall was very restricted and there were no epidemic areas. These
years, for the most part conspicuously free from manifestations of epidemic
malaria, were therefore also years of small and even deficient rainfall.
1900.
The 10-inch line only includes about half of the Punjab, but the 20-inch line
extends nearly as far and the 30-inch line includes Jullunder, Ludhiana and most of
Gurdaspur and Hoshiapur. A line representing a fall of 20 inches and over in-
cludes Umballa, half of Ludhiana and parts of Hoshiapur and Jullunder. The
epidemic of 1900 affected especially the last mentioned districts. Karnal, which
was not included but lay just beyond the 30-inch line, was also severely affected.
A small area of epidemic is seen in the old bed of the Beas near Kasur.
1894.
There is a marked extension of the 30-inch line which includes Gurdaspur,
Amritsar, Jullunder and even parts of Ferozepore, as well as Ludhiana, Umballa,
Karnal, etc. The 40-inch line includes Gurdaspur, Hoshiapur and Jullunder. If
rainfall alone were concerned, the epidemic should have equalled in area and
intensity that of 1900. As a matter of fact the area was small and for the most
part of low intensity. Nevertheless it corresponds almost exactly to the area of
greatest precipitation.
94
1892.
In 1892 the 10-inch line includes the greater part of the Punjab, vide Map V.
The 20-inch line includes Gujrat, Gujranwala, Lahore, half of Ferozepore and all
the eastern districts. The area of rainfall receiving 30 inches and over is not
extensive it includes only Gurdaspur, Ludhiana, Umballa and parts of
adjoining districts. But the 40-inch line as in 1900 extends to a considerable
distance from the hills.
In this year, which it will be remembered is one in which a terrible epidemic
involved the northern districts, the rainfall and the epidemic areas seems at first
sight to bear no relation to one another. But we notice as in 1908 a great westerly
extension of the area of heavy rain along with which we have epidemic conditions in
Gujrat and Gujranwala and epidemic malaria of moderate intensity in. Shahpur
district. Over Gurd aspur also it is possible to account for the malaria by the
rainfall. But Sialkot which was severely affected is far to the west of the centre
of precipitation.
1890.
I have been unable yet to study the detailed figures for this year, which is the
more unfortunate as this, besides being one of the most severe, is the most compact
epidemic on record. But very heavy rain fell over Sialkot, Gujrat and Gujran-
wala, the chief seats of the epidemic.
1884.
In this year most of the Lahore district, Ferozepore and parts of Sirsa
received less than 10 inches total monsoon rain. The 20-inch line extended only
as far west as Amritsar and Ludhiana. At first sight there is but little relation
between the area of heaviest precipitation and the large epidemic area. But
scrutiny of the rainfall map shows an area of heavy precipitation further south
than usual which, if we take into account flooding, accounts for some of the
southern portions of the epidemic. North of Gurclaspur there is another centre
of heavy precipitation and associated with it an epidemic area. As in the case of
1892 we can only explain the epidemic nucleus in Luhdiana and over the Sutlej
by indirect effects (flooding).
1881.
The great epidemic of Amritsar in 1881 was associated with unusual precipita-
tion over this city.
1879.
There was excessive rain over the southern districts in this year.
From these facts it is clear that epidemics are associated with areas of heavy
precipitation and tend not to occur in years of deficient rainfall.
95
III.—ASSOCIATION OF EPIDEMICS WITH YEARS OF LOW AND HIGH RAIN-
FALL.
In the Appendix are given the monsoon average of twenty-four recording
stations in different parts of the plains of the Punjab for a large number of years.
Recollecting what we have learnt regarding the general plan of distribution of
rain in the Punjab, these figures can be made use of as a fairly reliable guide to the
degree of precipitation and its extension to the west.
Years of Low Rainfall.
Taking first years of low rainfall, we see as we might expect that they are more
or less conspicuous as years of low fever mortality.
Years of High Rainfall.
Taking years of high rainfall, we also see a frequent association between years
of heavy rainfall and high fever mortality but in this case it is evident that this
relation by no means invariably holds good. In 1875 the rainfall is the heaviest
recorded in the Punjab not even excluding the rainfall for 1908. Extremely heavy
rain fell also over Gurdaspur and Sialkot. But the epidemic increase in deaths
is small. In 1894, another very heavy year, the mortality we have seen was not at
all in proportion to the precipitation. In 1884 the rainfall was not abnormally
great nor is there any reason that one can see why 1893 should not have been a
fever year as well as 1892, the precipitation being even greater. In 1909 also .
rainfall was distinctly high, but the year was almost free from epidemic disease.
This want of relation is brought out quite as prominently by a study of the figures
for different areas and is not due, as one might think, to the average figure
employed, giving faulty impression of the conditions.
Years of High Rainfall following Years of Deficient Rainfall.
I f , i n s t 0 e a d o f m e r e l y l o o k i n g f o r a n a s s o c i a t i o n o f h i g h r a i n f a l l w i t h e p i d e m i c s ,
we take also in consideration the previous year, we find several very striking ex-
amples of instances where a deficient rainfall followed by an excessive rainfall
is associated with epidemic conditions. The association of this condition with
epidemics is made very plain by the series of figures which are obtained
by dividing the average rainfall of each year by that for the previous year, the
object being of course to bring into proportionate prominence years of heavy rain-
fall following years of deficient rainfall, vide Appendix, col. 5. It will be noted that
the process not only picks out most of the epidemic years but in any particular
year even approximates in value to the number of deaths from fever. The
matter will be further commented upon in a later chapter. For the present we need
96
only point out that a consideration of rainfall alone does not enable us to pick out
fever years with any certainty.
IV.—TEMPERATURE.
The variations of temperature recorded for the Punjab show a very regular
yearly course. The most marked features are :
—
1. The great regularity of the seasonal variations.
2. The drop in the autumn temperature occurring between September and
October.
An examination of the records for epidemic and non-epidemic years and for
epidemic and non-epidemic areas has shown no distinctive features, that are not
so far one can see merely the effect of unusually heavy rains.
But there is a way in which variations in temperature may be important. We
have seen that rain begins to fall in June and that abundant anopheles are present
from July onwards. There seems no reason this being the case why epidemic con-
ditions should start so suddenly with such remarkable rapidity at the time they do.
Local conditions seem to have little or no effect in determining the period of onset,
and as we have seen the effect is almost simultaneous throughout the Punjab. This
onset corresponds very closely with the sudden drop in minimum temperature, and
temperature may therefore be an important factor determining the time of onset of
an epidemic, other conditions having brought all the necessary factors together for
its appearance.
V.—AREAS OF EPIDEMIC FREQUENCY.
Whatever the cause of epidemics maybe, it is very noticeable that for some
reason or another they have chosen to fall over some areas more frequently than
over others. In Map 11 are shown superimposed the effects of the epidemics we
have been studying.
Four distinct areas of special epidemic frequency are clearly seen, a northern
area in which the epidemic centres have ranged about Gurdaspur, a central area
about Umballa and Ludhiana and a southern area in the neighbourhood of
Gurgaon. The fourth type have their centres at or about Jullunder. Omitting
1908, the seven major epidemics have been distributed as follows :
—
Three, those of 1876, 1890 and 1892, are northern; three, those of 1878, 1884
and 1900, are central, and one, that of 1879, southern in type.
The most severe epidemic of the fourth type was that of 1878 the mild
epidemic of 1894 was over the same area. In 1908 there were two epidemics,
one northern and one southern in type.
97
It will be noted that though the northern area has suffered from epidemics of
great area and intensity, it is well to the west of the centre of greatest precipita-
tion. This alone will show the want of exact correlation between rainfall and
epidemic malaria. At the same time the dependence of the condition on rainfall is
shown by the fact that the northern epidemics occur in years of great westerly
extension of precipitation.
The localisation of epidemic conditions to the submontane tracts, which is very
clearly shown in Map 11, also shows that a certain rainfall is a necessary factor in
the production of epidemic malaria.
98
CHAPTER XII.
Physical Features in Relation to Epidemic and Endemic Malaria.
I.—SUBSOIL WATER.
Observations at different places visited have shown a marked relation between
the level of the subsoil water and malaria. Classified according to the depth of the
subsoil water at the different places visited, these may be grouped as follows :—
Time visited.
Village or Town.
Approxi-
mate
depth of
subsoil
water in
feet.
Spleen
rate in
percent-
age.
Epidemic
figure in
1908.
April 1909
.
.
Palwal .
.
.
.
.
.
.
4
85
. .
Janoali .
.
.
.
.
.
.
3
100
..
Dhatir .
.
.
.
.
.
.
10
73
. .
March 1909 & March
1910.
Amritsar (periphery)
.
.
.
.
6
90
12
Atari .
.
.
.
. . .
9—12
80
5
Rangahr
.
.
.
.
. .
8
93
7
Kahangahr .
.
.
.
. .
10
93
. .
Mahawa
. . . . . .
5
. .
18
March 1910
.
.
Gumtala
. . . . . .
4
90
12
Khairabad
.
.
.
.
.
.
10
..
2
August 1909
.
.
Bhera .
.
.
.
.
.
.
8
83
..
Miani .
.
.
.
.
.
.
6—12
78
..
Alipur . . . . . . .
10
94
30
Jamat Rangha
.
.
.
.
.
8
88
20
Dhel
.
. . . . . .
9
85
18
Hafizabad
.
.
.
.
.
.
8
95
18
Kolian .
.
.
.
.
.
.
7
88
41
Khan Mohamed Wala
.
.
.
.
5
97
17
Hathiwind
.
.
.
.
.
.
12
74
..
August 1909
. .
N a b i s h a
.
25
67
9
B h a l w a l . . . .
38
29
1
Luliani
.
.
.
.
.
over 40
21
2
Kot Momon .
. . . . .
„ 40
0
1
August 1909
.
.
Akilshah
.
.
.
.
.
.
15
66
3
Shahpur
11
48
. .
Nathuwala .
. . . . .
8
40
1
Kandan
. . .
4
53
30
Wegowal
.
.
.
.
. .
30
68
10
Dharemia
.
. . . . .
30
48
..
August 1909
.
.
Gujrat
centre
. . . .
27
38
..
margin
.
.
8—10
51
. .
Gurali .
.
.
. . .
4
94
46
Kuthala
. . . . . .
3
80
27
Nurpur .
.
.
.
.
. .
3
52
. .
Nairowali
.
. . . . .
10
26
2
Shadiwal
.
.
.
. . .
13
42
25
99
The Relation to Endemic Malaria.
The effect of a high subsoil water upon endemic malaria is not difficult to
understand. Whatever the conditions, whether the soil be sandy or impervious,
a high subsoil level means the existence of perennial breeding places of anopheles
and all the conditions classically associated with this disease.
The existence of considerable malarial infection, when the subsoil water is so
low as 40 feet, shows that the relation is only a relative one.
The Relation to Epidemic Malaria.
in this respect we have a more difficult problem. It is clear that the mere exist-
ence of a high subsoil water does not in itself lead to epidemic malaria, as is evident
from the conditions in Amritsar and in the villages of the Amritsar thana in
1909 and 1910, when a high subsoil level was associated with no epidemic increase of
mortality.
II.—POROSITY OF THE SOIL.
Experiments to ascertain the relative porosity of the soil were undertaken with
samples of soil from Palwal, Dhatir, Pirthala, Amritsar and Sheikpura and else-
where. The method finally used was the following :
—
A sample of soil was allowed to dry, and was then roughly broken up and a
portion of it passed through a sieve. After mixing the sifted material to ensure a
uniform sample 20 grams was weighed out.
This was then placed in 100 cc. of distilled water and shaken in a laboratory-
shaker for an hour. It was found that the values given later depended very largely
on the amount of shaking. After shaking the sample was poured rapidly into a
tube prepared as follows. A straight lamp glass with a bulb at one end is prepared
by tying over the straight end a piece of muslin. Into this is tilted 20 cc. of dry
washed sand and the tube is placed at rest with the muslin just submerged in a
vessel of water. When the sample is ready, it is taken from the shaker, rapidly
poured through a funnel into the tube, water being added to fill the tube up to the
top. Subsidence takes place rapidly at first but very slowly later, so that in the
case of the Punjab soil it often takes several hours for the bulb of the lamp glass
to empty itself. So soon as the fluid reaches the lower end of the bulb the time
is noted and 50 cc. of water is added. The numbers of hours taken before the
level again reaches the bottom of the bulb was then recorded. If the lower end
of the tube is not submerged the rate of percolation will be modified by capillarity
in connection with the muslin, the method the drop falls and so on by placing
the end of the tube under water this fallacy is done away with.
The chief difficulty to be got over is the great variation which results from
different degrees of shaking and so far this has prevented any really reliable
o2
100
figures being obtained. But the following observations serve to enlighten us in
some respects as to certain factors concerned in water-logging.
Series 1. Sand washed and shaken
. . 30 seconds under 1 minute.
„ „
„
.
. . 3 minutes in both cases.
Amritsar soil shaken
.
.
. 30 seconds 40 minutes.
„
„
„
.
.
. 3 minutes 147
„
„
„
„
.
.
. 10
„ 250
„
„ ,,
„ .
.
. 30
,,
375
,,
Porosity is therefore not only a matter of the original character of the soil
but depends upon the effect water has in resorting out its particles. The impervi-
ousness noted in the longer shakings was due to quite a thin layer of very fine
mud last deposited from suspension.
Series 2. Mean of a number of observations on soil shaken 30 seconds.
Pirthala soil
(sandy) .
.
.
.
. 25 minutes.
Amritsar soil
(close)
. .
.
.
. 55
,,
Palwal soil
(very close)
.
.
.
. over 4 hours.
Series 3. Mean of a number of estimations using the method described above
with shaking for one hour.
Dhatir soil
(sandy)
. .
.
.
. 4.25 hours.
Pirthala soil
(sandy, but less so than above) . 7 hours.
Palwal soil
.
.
.
.
.
. 11.5 hours.
Even the washings of a soil that are obviously sandy may form therefore a
very impervious layer. The very slow percolation under these conditions is very
marked.
Capillarity and Gravity.
Series 4.
Palwal soil, an estimation as above
.
.
.
. 660 minutes.
Palwal soil, an estimation as above, but end of tube buried
in dry sand instead of being allowed to rest in water . 35 minutes.
In the former gravity alone is in action. In the latter this is aided by the
action of capillarity exerted by the dry sand upon which the tube rests. The
action of capillarity under these circumstances in causing percolation is therefore
as compared with gravity enormous. Such experiments were repeated under
various conditions, in every case yielding results which showed that when dealing
with an impervious soil the effect of capillarity was immensely greater in causing
percolation than was gravity alone.
Two l ong tubes, ½ i nch di ameter, were fi l l ed ( a ) w i t h p o w d e r e d P a l w a l e a r t h ,
( b) with fine dry sand ; both were shaken down as much as possible and the tubes