The great value of the quartz mercury arc ultraviolet ray as a therapeutic measure in various diseases, but especially in rickets, tetany and in certain forms of tuberculosis, has been established beyond question in numerous reports by men of excellent standing, appearing especially in German journals.
As a result a great deal of enthusiasm has been developed for ultraviolet ray therapy and for light therapy in general as well. The latter was responsible for some very interesting work by Oeken1 on the use of heatrays in the field of otology. To produce these rays, a small, 600 candle power, white glass "Sollux" lamp was used, which is the same, or practically the same, as the higher Watt white glass nitrogen bulbs made in the United States. In the "Sollux" outfit the rays are projected forward and concentrated without causing a burn by the use of a parabolical concave reflector