Our purpose is to compare clinical experiences and observations of the action of light on different diseases, with corresponding observations from the laboratory of the effect of light on some experimentally produced diseases in animals, and thus contribute to our knowledge of the relation between light and some of the vitamins, especially the so-called antirachitic vitamin and vitamin A substance.
The experiments on animals were, for the most part, carried out in American and English laboratories, and the results have been published during the last few years.
The clinical experiments were made at the Danish State Hospital. Even when it was opened in 1910, a room was equipped for giving Finsen light baths (carbon arc light with two lamps of 75 amperes). When we heard of the excellent results obtained by Reyn and his collaborators in the treatment of surgical cases of tuberculosis with the carbon arc light, we