“…Erythrocyte protoporphyrin, normally up to about 50 microgrammes per 100 millilitres of cells, is almost doubled in hcemolytic and refractory ancemias and in diseases of the leucocyte and lymphocyte systems (Ward and Mason, 1950). It is low in pernicious ancemia in relapse; but particularly high values, above IOO microgrammes per IOO millilitres of cells, are found in iron deficiency and lead poisoning.…”