III. TOLERANCE FOR MERCURY POISONING INCREASED BY FREQUENT HEMOGLOBIN INJECTIONS.

Frequent injections of superthreshold amounts of dog hemoglobin will cause deposits of pigment material in the renal tubular epithelium. When this has happened this dog will survive minimal lethal doses of mercuric chloride with little evidence of renal injury. In fact some dogs will tolerate twice the minimal lethal dose without severe reaction. There is no evidence that continued injections of dog hemoglobin in these amounts will cause any injury or functional disability of the kidney. Rest periods will effect a disappearance of this pigment in the renal tubules.