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clearly as possible the real endemic areas in Bengal and also the regions
which are specially liable to extensive epidemics of the disease. Studies
on the chemical structures of the vibrios and the relation of the structure
to pathogenecity has formed another subject of extensive researches. Much
light has been thrown on some of the obscure problems of cholera, but a
great deal still remains to be done specially in regard to the basic differences
between the endemic and non-endemic regions. The available methods
for forecasting cholera epidemics have been scrutinised and a new method
has been evolved which has given satisfactory results with regard to the
Calcutta experience.

      (ii) Epidemic dropsy.—Epidemic dropsy is one of the major problems of
Bengal and other eastern provinces. This is not so much because of the
mortality it causes, but because of the permanent damage to the heart,
the eyes, and other organs of its numerous victims. The aetiology of the
disease has been shrouded in mystery. As a result of detailed investiga-
tions of a number of epidemics, it was suspected that certain consignments of
mustard oil were responsible for the outbreak of the disease. More definite
evidence pointing towards the same conclusion was obtained during an
outbreak at Jamshedpur and feeding experiments on human volunteers
with the oil obtained from that source produced definite signs and symptoms
which in the opinion of experienced physicians were identical with mild cases
of epidemic dropsy. Subsequent experience in the field appears to confirm
the view that certain supplies of mustard oil cause the disease. The
nature and origin of the deleterious substance contained in the oil are still
unknown and investigations on the subject are proceeding. Other current
theories were subjected to critical examination but none of them could be
supported by facts which emerged out of the investigations.

      (iii) Tuberculosis.—Tuberculosis is a major public health problem in
India today and yet very little research is being done on it. There is
ample evidence to show that the problem in India differs markedly from the
problem in western countries and that unless it is properly studied a satis-
factory solution cannot be arrived at. Investigations have been conducted
on the epidemiological, pathological and bacteriological aspects of the
disease, and valuable contributions to the subject have been made. The
public health aspects of the disease, specially those arising out of industries
and urbanising of the population, are being investigated, and those peculiar
to India have also been clarified.

      (iv) Malaria.—The rural malaria problem in India is recognised to be one
of the most stupendous and one of the most difficult to solve. The
Institute has organised field centre where investigations on rural malaria
are carried out. The value of various control measures suitable for em-
ployment in rural areas are being tested. Among other problems laboratory
investigations on the role of the spleen and reticulo-endothelial system in
immunity to malaria have been conducted and very interesting results have
been obtained. Studies on the mechanism of haemolysis in blackwater
fever are in progress. The results so far obtained show that probably
certain unsaturated fatty acids produced as a result of altered metabolism
are responsible for the haemolysis. Considerable progress in the treatment
of blackwater fever has been made. Administration of ascorbic acid
glucose and cortical extract has given encouraging results.