An Arabic translation of a text entitled "Keys of Wisdom," by the famous fourth century alchemist Zosimos, has been found in an Alchemy book written by a twelveth century Kurd, named Al-Tughra'i. The book starts with a discussion of the "four elements" (fire, air, water, and earth) and the "four natures" (hot, cold, moist, and dry), and continues with their quantitative estimation. This is followed by a determination of their ratios, which is needed to moderate the properties of metals and to form the elixirs used in transmutation. Although today's chemists disagree with most of these concepts, they must marvel at some of the ideas found in the present text. For example, Zosimos correctly understood the relationship between heat and movement, and in a remarkable statement he explains why, during distillation, vapors rise against gravity, by saying: "Motion is due to heat for without heat there would be no motion." This statement is true today and is taught in most thermodynamics text books. Alchemists also distinguished between distillation, and "smoking" (pyrolysis), and recognized the importance of the first in purification. Furthermore, they correctly believed that the physical properties of substances are directly related to their chemical composition and developed a highly sophisticated system to characterize compounds by means of nine tastes, three smells, and a multitude of colors.