1904-5.] Nie”s R. FINSEN—HIS LIFE AND WORK. . 113 
his former results, and besides, stamped the ultra-violet rays as the essen- 
tial exciting cause of the action. 
The experiments were carried out with great care and many pre- 
cautions, in bright sunshine at mid-day, just as the embryos were emerging 
from the eggs. They were exposed to various colored lights, also to clear 
light and to shade, for stated times, and the movements carefullv noted 
and counted, and showed that movements in the shade increased pro- 
portionally to the repetition of the experiment. Then they were allowed 
to rest in the shade undisturbed for several hours, when their movements 
were again counted. Suspecting some error, the experiment was carried 
out in another form. Three embryos being placed in the same flat dish 
used throughout, and being in the shade for five minutes, during which 
time only one movement was noted, were exposed to direct sunlight for 
five minutes, and then removed to the shade, and kept there for the re- 
maining observations. During an exposure of five minutes to direct 
sunlight 45 movements were counted; during five succeeding minutes in 
the shade 107 movements were counted; during the next five minutes, 
still in the shade 112; then 75, 30, 32, 29, 22, 28. This experiment is 
quoted thus fully to illustrate how simple may be researches, fraught 
with immense potentialities, provided the observer possess the genius of 
interpretation, It meant that the effect of the chemical rays was only 
evident after a certain time, and might even attain its maximum after 
exposure to them had ceased, and, finally, suggested opportunities for new 
researches. 
In this same paper Finsen alludes to another matter. Recalling his 
former suggestion of utilizing the chemical rays as a method of medical 
treatment of disease by light baths of the whole body, he draws attention . 
to the fact that some charlatans, wishing to trade upon the reputation 
achieved by his researches, were employing incandescent electric light 
baths, pretending that they were based upon his work, and likewise using 
his name in a manner most distasteful to himself. Therefore he is impelled 
to remind the medical profession that the influence of light as a germ 
killer, and its power to cause inflammation and pigmentation of the skin, 
as well as its stimulating action, are dependent upon the chemical rays, 
and the light from ificandescent electric lamps contains much less chemical 
rays than ordinary diffuse daylight, and that such baths acted by reason 
only of the heat rays given off by the lamps, and are simply of use to 
promote perspiration. 
Proper light baths, on the contrary, are cold, and cause a marked 
effect upon the skin. His recent researches proved that the dilatation of 
the capillaries and bloodvessels of the skin produced by the light is not 
