Abstract
The relation of the serum Ca to the inorganic and total acid soluble P in parathyroid deficiency and parathormone over-dosage is discussed. It is found that parathormone reduces the inorganic and total acid soluble P of the whole blood until the Ca rises markedly above the normal. The inorganic P then rises rapidly, usually followed by a marked rise in the total acid soluble P until death ensues.