in excessive amounts cause headache, palpitation,
insomnia, and anemia. These same authorities condemn sun-baths to the
naked body of the tuberculous, claiming that any cures effected are
consummated despite the injury done by the energy of short wave-length.
There is no doubt that these rays are beneficial in local lesions, but
it is believed that the cure is due to the irritation caused by the rays
and the consequent bactericidal action of the increased flow of serum,
and not to any direct beneficial result on the tissue-cells. Others
claim to cure tuberculosis by means of powerful quartz mercury-arcs
equipped with a glass which absorbs the ultra-violet rays of shorter
wave-lengths. These conclusions by a few authorities are submitted for
what they are worth and to show that this phase of light-therapy is also
unsettled.

Any one who has been in touch with light-therapy in a scientific role is
bound to note that much ignorance is displayed in the use of light in
this manner. In fact, it appears safe to state that light-therapy often
smacks of quackery. Very mysterious effects are sometimes attributed to
radiant energy, which occasionally border upon superstition.
Nevertheless, this kind of energy has value, and notwithstanding the
chaos which still exists, it is of interest to note some of the
equipment which has been used. Some practitioners have great confidence
in the electric bath, and elaborate light-baths have been devised. In
the earlier years of this kind of treatment the electric arc was
conspicuous. Electrodes of carbon, carbon and iron, and iron have been
used when intense ultra-violet rays were desired. The quartz mercury-arc
of later years supplies this need admirably. Dr. Cleaves, after many
years of experience with the electric-arc bath, has stated:

From the administration of an electric-arc bath there is
obtained an action upon the skin, the patient experiences a
pleasant and slightly prickly sensation. There is produced,
even from a short exposure, upon the skin of some patients a
slight erythema, while with others there is but little such
effect even from long exposures. The face assumes a normal rosy
coloring and an appearance of refreshment and repose on
emerging from the bath is always observed. From the
administration of the electric-arc bath there is also noted the
establishment of circulatory changes with a uniform regulation
of the hea