1. It has been shown that hemoglobin in solution or within the red blood corpuscles can be oxidized by hydrogen peroxid to form a colorless substance capable of manifesting a microchemical reaction for iron, the type of the reaction depending upon the degree of oxidation.
2. It has been further shown that hematin and hemin, when treated with hydrogen peroxid, are decolorized. The colorless or nearly colorless body, preserving the form of the original body and being an intermediate product of its oxidation, will also exhibit a typical reaction for iron.
3. A method has been described for obtaining microchemical reaction for iron from hemoglobin and its various modifications and iron-containing derivatives, from tissue cells, from cell nuclei, and from eosinophil granules, by an appropriate degree of oxidation with hydrogen peroxid.