SUN RAYS—ABBOT 169 
been collected and accurately selected by the optical spectroscopic 
train. It may be that specific functions like flower bearing, seed de- 
veloping, leaf growing, and stem expansion may be found to require 
different and very special qualities and intensities of rays for opti- 
mum conditions. The experiment is fascinating, for perhaps new 
and remarkable varieties of the most useful plants may be developed 
by controlling their radiation supply. 
With the higher plants, it must be sunshine or death. With man 
and the higher animals, it must be sunshine or sickness. 'To be sure, 
there is nothing in the life of man or animals like the photosynthesis 
of the food of all plants and all animals which goes on in green 
leaves. That is unique with plants. But child humanity in dusky 
cities, shut in by smoke and dust from receiving the ultra-violet rays 
of the sun and sky, is afflicted by rickets and other ills which yield 
to the healing influence of exposure of the body to full sun rays in 
the manner that nature intended. 
The outstanding exponent of this solar therapy is Doctor Rollier of 
Switzerland, who has maintained a sanitarium for sun treatments 
since 1903. Of later years, he has been imitated in other countries. 
One would hardly think of sun rays as dangerous, but the patients of 
Doctor Rollier commence their treatments on the first day with only 
20 minutes exposure, and of the feet alone. From this gentle begin- 
ning there is a gradual progress to the stage of complete exposure of 
the person for hours. Naturally there accompanies this course a 
gradual darkening of the skin. The patients become brown and 
hardy looking. Skin sores disappear. 
Two principal diseases successfully treated by solar therapy are 
rickets and surgical tuberculosis. Rickets, as everyone knows, is a 
sort of lack of stamina, apt to invade the whole body of children. 
A weak digestion, a poor appetite, emaciation, profuse night sweat- 
ing, weakness of the limbs, tenderness of the bones, enlargements of 
the wrists and ends of the ribs, bow legs, curvature of the spine, 
misshapen head, contracted chest—all these deformities and miseries 
may come in the early years of the poor little patient. 
The layman is apt to think of tuberculosis as a disease of the lungs, 
but essentially the same malady attacks many other parts of the 
body. Glands of the neck, skin, bones, joints, mucous membranes, 
intestines, and liver are commonly infected by the tubercle-bacillus. 
In cases of superficial tuberculosis, recognizing how the germs may 
pass from one part to another in the blood stream, the surgeon is 
frequently called in to excise the infected part before it does its fatal 
mischief in a less accessible organ of the body. ‘This gives rise to the 
term surgical tuberculosis. 
It appears to be definitely proved that ultra-violet rays of less 
than 3,200 Angstréms in wave length are the active agents in the 
