regarding
blue light; under exposure to which a sufficient measure of
insensibility to pain can be induced as to allow the performance of
minor surgical operations (such as are connected with dentistry, for
instance) painlessly. For this effect nothing more is required than an
electric light (of sixteen candle power), a blue glass globe, and a
sheet of blue satinette. The lamp is fixed in front of the patient's
eyes, at a distance of a few inches ; and the patient is directed to
stare at it, keeping his eyes wide open. His head, and the lamp, are
then covered with the blue cloth, so as to exclude all natural light;
and he is assured that, if he keeps on staring, he will be unconscious
of any pain during the operation which is about to be performed. Then,
if the cloth is removed after the lapse of from two to three minutes,
the patient will be found in a condition of general insensibility to
pain, sufficiently deep for the performance without pain, of any brief
surgical operation. The idea naturally occurs to one's mind that this
result is actually brought about through such seif-suggestion as is now
named hypnotism. But this supposition is negatived by Professor
Redard's statement that he has failed to produce the same phenomena
with either yellow, or red light. Nevertheless a consensus of opinion,
medical, and lay, testifies to the importance of wearing red in a
tropical country when exposed to the sun's direct rays. Dr. Olpp, for
instance, by wearing a red-lined hat suffered far less headache through
prolonged exposure to the sun than before resorting to this measure.
The Chinese Mandarins in the South, for their official duties out of
doors, invariably protect themselves by a baldachin of red hue. Again,
there is the red fez of the Turk, the preference for
