SINCE 1912, when Voss1suggested the possibility of a relationship between otosclerosis and disturbances of the function of the parathyroid gland, various investigations have been published with the object of demonstrating metabolic disturbances of different kinds in association with this disease. Attention has been focused particularly on the calcium metabolism. However, there have been reports also on investigations of the inorganic phosphate, cholesterol and protein contents of the serum, as well as a few on the serum potassium, magnesium, chlorine and lactic acid, the alkali reserve, the sugar metabolism and the basal metabolism. The latter investigations comprise only fairly small materials, and no great importance seems to have been attached to them. The results achieved by the various investigators are not comparable. A brief survey, therefore, will be given here of the most important reports, comprising studies concerning calcium, inorganic phosphates, cholesterol and protein. SURVEY OF THE LITERATURE Calcium