السيمياء في الممارسة .. الإسكندريه والسيمياء

Alchemy in Practice.. Alexandria and Alchemy

Alchemy in Practice

From what remains of these scrolls we learn how the rich philosophical heritage and practical culture together give us a picture of alchemy in the Alexandrian school and that the applied approach was dominant at least at first.

The common approach, for example, was to try to make the material look as much like gold as possible based on the theory that if the material acquired enough of the properties of gold it would eventually become gold, a direction that seemed reasonable. When it was found that the surfaces of metals could be dyed white by arsenic sulphide and yellow by various sulphides, the search turned to finding the appropriate dye to produce real gold. Another theory involved treating metals as living organisms so that they would reach gold in the most perfect form, by isolating the spirit of gold and transferring it to the base metal. As was the case in all directions, the methods used included distillation, sublimation (the conversion of solid matter by heating to a gas without a liquid phase, melting and dissolving (dissolving), filtration, crystallization, and calcination (heating at high temperatures without melting), which usually meant oxidation (the introduction of oxygen into the air).

Figure (1/2) A living sign of Ouroboros, signifying the eternal cycle of change, life and death, seasons, transformation, gift of the John F. Kennedy Library, California State University, Los Angeles).

Certain chemicals became popular in the practice of alchemy because of their ability to affect the change of materials. The most important of these chemicals were mercury, a liquid metal, and sulfur, a combustible stone. It was fascinating to watch the process of mercury being poured onto many pure metals and combining with the metal to form mercury-containing alloys or amalgams, and this was in fact a well-known method of purifying gold: extracting gold from the ore or from any other composition with mercury inside the mercury. The mercury could then be expelled by heat, leaving behind the pure metal.

Alchemists used amalgams prepared in this way to create a silvery appearance. When amalgams were treated with sulphides they developed a yellow color or turned to gold.

Corrosive substances were of interest, such as acids, hydroxides, and ammonium chloride, which decomposes on heating to ammonia and hydrochloric acid, which attack metals. Arsenic was considered by alchemists to be a type of mercury, because it sublimates like mercury, forms soft alloys like mercury, and has a sulphide similar to mercury sulphide. Arsenic's property was widely used to color metals. Vitriol (sulphate of copper and iron) was of interest to alchemists, perhaps because of its colors. Copper sulphate forms blue crystals and a beautiful blue solution, while iron sulphate is green. We can write with confidence about the materials and techniques of the past because of the efforts of a few alchemists to preserve this information in writing. We mean three of them: Pseudo-Democritus, Mary the Jewess, and Zosimus.