766 
H. DE VARIGNY. 
the use of red glasses whieh permit only the passage of the rays 
of the red extremity of the spectra and arrest all the chemical 
ones. Of the method, Mr. Finseii speaks highly. Tried at the 
hospital of Anbervilliers, four years ago, under probably defec¬ 
tive conditions, it has not given very successful results. The 
method has also been experimented with in New York. 
However, this negative form of phototherapy was used 
years ago. At the beginning of the 14th century the beds of 
variolar patients were often covered or surrounded with red 
draperies ; this color being probably considered as having the 
mystic power of chasing the disease. 
A positive form of phototherapy is offered to us by the 
recently invented method of the treatment of lupus'again by 
Finsen. 
Lupus is tuberculosis of the skin, local, superficial and rebel¬ 
lions to treatment. Existing through the life of the tuberculous 
bacilli, those are difficult to destroy. 
Light killing microbes, Finsen has demanded it to do 
what antiseptics have so far been unable to. 
But, while in variola it was necessary to use negative 
therapy by removing the irritating properties of light, in lupus 
it is precisely rays having these properties that must be used. 
In one case the light must be attenuated, in the other it must 
be increased. 
As the chemical rays are those which, no doubt, have the 
bactericide power, it is evident that to act on the bacilli of 
lupus, the chemical rays must be used in preference to entire 
white light. 
Anyhow it is as easy to arrest, by appropriate media, the 
rays of the red extremity of the spectra as those of the purple 
extremity. Mr. B^inseu has then filtrated his light, solar, or 
electric, through a solution of blue of methylene, or of sulphate 
of copper ; through this solution the blue-purple rays alone pass, 
the others, from the green to the red, are cut off. This under¬ 
stood, the method of Mr. Finsen is easily explained : the patient 
is seated facing a filtrating apparatus; the rays oozing from the 
