Both a-hematin and iron porphyratin are so sensitive toward HC1 in methyl alcohol that when boiled with this reagent under a reflux condenser a few min. they undergo a conversion. This can be explained by the saturation of several bonds. If the heating in this reagent is carried out long enough and the product is saponified and freed of Fe there is obtained a porphyrin, not previously described, which is different from hemateric acid but closely related to Nencki''s hematoporphyrin. It differs from this latter, however, in having a much higher HC1 number, similar to that of hematoporphyrin-dimethyl-ether, so that by Willstatter''s fractionation method it can be differentiated from hematoporphyrin. On boiling 15 min. with 25% HC1 it loses for the most part its chloroform solubility and the HC1 number approaches that of Nencki''s hematoporphyrin. The plant porphyratin and a-hematin, aside from having approximately the same Fe content, are most similar in the ease with which their porphyrin derivatives can be electrochemically reduced. Likewise, by boiling with 1% HC1 in methyl alcohol a product is obtained from each which on saponification with alkali and freeing of Fe gives porphyrins having the same properties. A method is described for preparing yeast porphyratin which is stable for at least a week.