The _Tractatulus Alchimiæ_ treats of the nature of the sophic mercury, which contains the sophic sulphur, and wherefrom every mineral substance was originally created by God. This mercury is the universal vivific spirit; there is nothing in the world to compare with it; it penetrates, exalts, and develops everything; it is a ferment to every body with which it is united chemically; it is the grand metallic elixir, both to the white, or silver, and red, or gold producing, degrees. Its potencies develop under the action of fire. Though found in all minerals, it is a thing of the earth. It possesses lucidity, fluidity, and a silverine colour. The perfection and the praise of gold are elaborately celebrated in succeeding pages. The _prima materia_ is declared to be of a duplex nature, and the duplex elixir, which is the result of successful operation, has powers that are beyond nature, because it is eminently spiritual. The strength of the perfect magisterium is one upon a thousand. The chemical knowledge of Avicenna is derived from Geber, as his medical erudition was borrowed from Galen, Aristotle, and other anterior writers. He describes several varieties of saltpetre, and treats of the properties of common salt, vitriol, sulphur, orpiment, sal ammoniac, &c. MORIEN, or Morienus, was a recluse born at Rome in the twelfth century, and who took up his habitation in Egypt, where he became profoundly versed in the chemistry and physics of the period. While his education was still progressing in his native city, and under the eyes of a father and mother who tenderly cherished him, he heard of the reputation of Adfar, the Arabian philosopher of Alexandria, and contrived to get a sight of his writings, when he was immediately seized with a desperate desire to understand their meaning. The first impressions of youth carried him away; he abandoned his home, and set out for Alexandria, where, after some difficulty, he discovered the abode of the philosopher. He made known to him his name, his country, and his religion, and both appeared well contented with each other--Adfar at having found a young man whose docility he could depend on, and Morien that he was under the discipline of a master who promised to unveil to him the source of all treasures. They studied together; the amiability of the pupil encouraged his instructor to make known to him all his secrets, after which, according to one account, Morien went on a pilgrimage to Jerusalem, and then turned hermit. It seems more probable that he tarried with Adfar till his death, which in spite of his immense treasures, his illumination, and his acquirements in arcane philosophy, eventually occurred, and that then Morien, having paid the last duties to his deceased initiator, quitted Alexandria, and proceeded on his pilgrimage. He purchased a retreat near the city of Jerusalem, where he settled in the company of a pupil, whom he doubtless intended to form for science.