Its elementary nature was imperfectly understood; and the impure specimens obtained by the early chemists explain, in some measure, its confusion with tin, lead, antimony, zinc and other metals; in 1595 Andreas Libavius confused it with antimony, and in 1675 Nicolas Lemery with zinc. These obscurities began to be finally cleared up with the researches of Johann Heinrich Pott (1692-1777), a pupil of Stahl, published in his Exercitationes chemicae de Wismutho (1769), and of N.
Pott, Der abendldndische Text d.
Pott showed that it did not contain iron and that it yielded a definite series of salts, whilst in 1774 C. Scheele proved that it was the oxide of a distinctive metal.
The like must be said even of the contribution to the problem made by August Pott,' though he has helped to define one condition of success - the classification of the strata in " Western " texts - and has taken some steps in the right direction, in connexion with the complex phenomena of one witness, the Harklean Syriac.