This is a famous medieval Arabic medicate treatise, by Abu Bakr Muhammad Ibn Zakariya al-Razi (ca. 251/864-313/925), and dedicated to al-Mansur (a governance of the province of Rayy where al-Razi was born. Al-Razi was, a Muslim Persian polymath, physician and philosopher. His contributions to various scientific fields were major. This is from the Series of Medical Heritage, a new series dealing primarily with texts of ancient medical manuscripts by medical scholars of Arab Literary Heritage.