Experiments are described which attempt to define the relation of methemoglobin to hemolysis. A comparison was made in vitro of the resistance of erythrocytes containing chiefly oxyhemoglobin or methemoglobin to hemolysis by saponin, hypotonic saline, bile salts and lysolecithin. These data are interpreted to indicate that intracorpuscular methemoglobin does not alter the resistance of erythrocytes to hemolysis by these lysins, although there are certain peculiarities in the results with bile salts and lysolecithin.
In the case of bile salts and lysolecithin, oxyhemoglobin or methemoglobin may have an equal or different inhibitory effect on hemolysis depending upon the conditions of pH and temperature.
Chronic methemoglobinemia in dogs maintained by the administration of sodium nitrite does not produce an anemia.
These data suggest that the formation of methemoglobin is an independent effect and not a part of the hemolytic action of certain chemical agents.