ABSTRACT
Szücs (1913) reported that hydrogen peroxide increased the permeability of the living cell. Following up a previous observation [Bokorny, 1886], he found that if threads of Spirogyra were treated first with hydrogen peroxide and then with ferrous sulphate solutions, a dark precipitate appeared within the cells. He concluded that the hydrogen peroxide had so increased the permeability of the cell that the ferrous ions were able to enter and form a dark iron-tannin compound. It was also found that hydrogen peroxide increased the permeability of the cell to various dyes. In view of the ever-increasing importance of the rôle assigned to hydrogen peroxide in cell metabolism it seemed worth while to re-open this question. As Szücs gives no details of his experiments, an exact repetition was impossible.
