The value of sunlight as a hygienic agent is so universally
recognized—theoretically if not practically—that we need not devote
space to its consideration in this connection. Sunlight is essential to
the healthy performance of the vital functions, and must be equally
important as an aid to remedial processes. This fact has been amply
demonstrated by hospital experience, which shows a much larger
percentage of recoveries in rooms abundantly exposed to the sun than in
those secluded from its rays.
That the sun has a powerful influence upon the skin is shown by the
great increase of pigment in that structure when freely exposed to the
sunlight. This results from an increased activity of the cutaneous
tissues.
Experience has shown that the sun bath can be employed to advantage in
most chronic diseases. The patient simply lies in a position in which
the naked skin can be freely exposed to the rays of the sun. The head
should be shaded. The bath should not be continued so long as to produce
unpleasant effects either upon the skin or the general system. It may be
accompanied and followed with the dry hand-rubbing.