116 TRANSACTIONS OF THE CANADIAN INSTITUTE. [Vor. VIII. 
blood out of the lobe by means of a piece of glass on each side of it, the 
paper was blackened in twenty seconds. So that blood has avery great 
deal to do with preventing the penetration of the chemical rays. There- 
fore he devised glasses of different shapes to press the blood out of parts 
while being treated. 
He was now ready to try this plan of treatment by concentrated 
chemical rays in different germ diseases of the skin, and especially in 
lupus vulgaris, which he considered presented especially favorable con- 
ditions, for it is caused by the tubercle bacillus, is local, is frequently 
superficial, and light can kill the Bacillus tuberculosis, and not only kill 
the germ, but also excite and stimulate nutrition and excite activity in 
granulation, thus assisting recovery. 
Fic. 1—Finsen’s Original Solar Apparatus. 
The method of treatment varied somewhat according to the severity 
of the disease, and the tolerance of the tissues to the action of light. 
An area of from one to three centimetres in diameter was subjected to 
the concentrated chem‘cal rays daily, for several days or several weeks as 
the case might be. The treatments lasted at least two hours at first, 
later, with improved apparatus, one hour. When one spot seemed to 
have been sufficiently treated, another was attacked until the whole 
affected area had been gone over. Then, if any suspicious spots were 
left, they were attacked. Patients were examined occasionally after 
some months, and treated, if necessary, until no further spots were to 
be found. Each patient had a nurse who kept the spot in range of the 
rays, and saw that the rays fell perpendicularly upon the pressure glass. 
The immediate effect of the treatment was to cause inflammation of the 
skin (erythema) which was sometimes quite severe, depending upon the 
intensity of the light and also on idiosyncrasy; sometimes there was swel- 
ling of the parts, sometimes blistering, and crusting over. 
