and believed that
the bacteria were directly destroyed by the ultra-violet rays. However,
many have since come to the conclusion that the beneficent action of the
rays is due to the irritation which causes an outflow of serum, thus
bringing more antibodies in contact with the bacilli, and causing the
destruction of the latter. Hot applications appear to work in the same
manner.

Primitive beings of the tropics are known to treat open wounds by
exposing them to the direct rays of the sun without dressings of any
kind. These wounds are usually infected and the sun's rays render them
aseptic and they heal readily. Many cases of sores and surgical wounds
have been quickly healed by exposure to sunlight. Even red light has
been effective, so it has been concluded by some that rays of almost any
wave-length, if intense enough, will effect a cure of this character by
causing an effusion of serum. It has also been stated that the chemical
rays have anaesthetic powers and have been used in this role for many
minor operations.

It is said that the Chinese have used red light for centuries in the
treatment of smallpox and throughout the Middle Ages this practice was
not uncommon. In the oldest book on medicine written in English there is
an account of a successful treatment of the son of Edward I for smallpox
by means of red light. It is also stated that this treatment was
administered throughout the reigns of Elizabeth and of Charles II.
Another account states that a few soldiers confined in dark dungeons
recovered from smallpox without pitting. Finsen also obtained excellent
results in the treatment of this disease by means of red light.
However, in this case it appears that the exclusion of the so-called
chemical rays favors healing of the postules of smallpox and that the
use of red light is therefore a negative application of light-therapy.
In other words, the red light plays no part except in furnishing a light
which does not inhibit healing.

Although the so-called actinic rays have curative value in certain
cases, there are some instances where light-baths are claimed to be
harmful. It is said that sun-baths to the naked body are not so popular
as they were formerly, except for obesity, gout, rheumatism, and
sluggish metabolism, because it is felt that the shorter ultra-violet
rays may be harmful. These rays are said to increase the pulse,
respiration, temperature, and blood-pressure and may even start
hemorrhages and