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INFLUENCE OF SOLAR RADIATION ON IMMUNITY, II [Vol. XXI, Part III.
Immunization with goat tissue vaccine. All the selected animals, belonging to
both the Groups, were inoculated subcutaneously each with 1 c.c. of 1 per cent
saline emulsion of the spleen tissue. Inoculation was always done in the evening.
Anti-rinderpest serum or a re-inforcing dose of goat tissue vaccine was not given
to any animal during the whole period of the experiment. Effect of a single dose of
goat tissue vaccine alone on the animal body under sun and shade was observed.
Description of the animal shed and place for exposure
The shed, where the experimental animals were sheltered, was constructed of
thatching materials. The inside of the shed was fairly dark and cool. Arrangement
for tying up the Sun Group animals during the period of the exposure was made in
the open space about ten yards from the shed. As the direction of the wind at
Izatnagar is generally from west to east and vice-versa, a 'tattie' (thatched wall)
all about 8 ft. high and 30 ft. long was constructed across the direction of the
wind and two similar tatties of same height and length were constructed at right
angles one on each side of the central tattie. The whole enclosure thus resembled
the capital letter H. Provision for tying up the animals was made by pitching
the wooden pegs on either side of the central tattie, distance between the pegs being
wide enough to prevent overshadowing of any animal by the other. The animals
were tied up on the eastern side of the central tattie when the direction of the wind
was from the west, and the arrangement for tying was reversed when the direction
of the wind was from the opposite side. All these arrangements were done with a
view to prevent the cooling effect of the wind on the animal body during the period
of the exposure. Maximum degree of photosensitization in the minimum time was
thus obtained by exposing the animals to the sun within this enclosure.
Exposure and general management of the animals during the immunizing period
Exposure of the Sun group commenced from the next day of the vaccination and
was continued daily for a period of about 8 to 10 days covering the negative and
positive phases of the period of immunization. The duration of exposure on each day
was determined by the atomospheric air temperature and the degree of tolerance of
the animals exposed to the sun. They were removed to the shed before the
distressing symptoms appeared. During the period of exposure, water was not
offered to the animals. They were also not allowed to lie down on the ground-
This latter precaution was taken for preventing the unequal absorption of the solar
radiation through the body surface. During this period of 8 to 10 days after
vaccination, the Shade Group was kept in the shed. Both the groups were
watered twice a day, once early in the morning and again in the evening. Animals
received a little walking exercise at the time of watering. In order to avoid
digestive disturbances due to any sudden change of fodder and concentrates, the
ration with which the animals were fed during the pre-experimental period, was
continued during the period of immunization. This procedure eliminated any
possible complication with the digestive disturbances associated with the course of
rinderpest.
Observations during the immunizing period.
(1) With a view to study the atmospheric air temperature and relative humidity
of the air inside the shed as well as in the exposed place, dry and wet bulb thermo-