This investigation was undertaken primarily as a clinical application of the work of Rohdenburg and Krehbiel1 on the effect of the removal of ductless glands in rats on the salt content of the blood. The fact that parathyroid deficiency is definitely associated with a low content of blood calcium also suggested a possible deficiency of other mineral salts in diseases of other ductless glands.
In the course of the investigation we soon found, however, that the relationship between the salt content of the blood and the disturbances of the ductless glands that came under our observation was not constant. We therefore extended the work to include all the clinical conditions at our disposal in the medical service at the Lenox Hill Hospital.
We studied as controls the patients on the surgical service who were admitted for some minor surgical condition, such as hemorrhoids or hernia, and who apparently were free