Lichtwirkung und antirachitischer Schutzstoff im lebenden Organismus. Experimentelle und klinische Untersuchungen zur pathologischen Physiologie der Rachitis als Mangelkrankheit.

The author presents the various theories that have held sway with regard to the cause of rickets, gradually leading up to the modern discovery of the direct effect of light and the indirect effect of the same agent through food materials. He then presents his experimental work, in which he claims to have demonstrated that: (1) skin becomes antirachitically activated by exposure to a quartz mercury vapor lamp, and this activity is in part transposed to the nonexposed areas; (2) antirachitically activated skin can exert its effect parenterally when implanted in another part of the body; (3) exposure of the animal to ultraviolet radiation leads to an increase in vitamin D content of the internal organs, such as the liver; (4) splenectomy has no effect on the production or the cure of rickets; (5) the ultraviolet irradiation of a lactating animal such as the cow produces an increase in the