The Sulphur Mercury Theory

Among other Arabian alchemists the most celebrated were Avicenna and Rhasis, who are supposed to have lived some time after Geber and to whom, perhaps, the sulphur-mercury theory may have been to some extent due. 

Rise and Spread of Alchemy. The Nature of Alchemy. Alchemical Theory. The Sulphur-Mercury Theory. Alchemical Representations of the Sulphur-Mercury Theory. The Emerald Table of Hermes. The Tria Prima of Paracelsus. 

The Muslim alchemists adhered essentially to the Aristotelian philosophy, although they modified it in certain ways. In particular, the sulphur-mercury theory appears basically as a derivative of the theory of the Four Elements. The apposition of the two opposed, or contrary, elements, fire and w ater, now assumed a new guise. Fire became Sulphur, and Water became Mercury, These names must not be identified with the material substances, sulphur (brimstone) and mercury (quicksilver). They denoted abstract principles, composed of hot and dry (sulphur) and cold and moist (mercury) natures. In alchemical writings they were often called sophic (or philosopher s) sulphur and sophic mercury, or our ... 

In terms of the pictorial symbolism which forms so important a characteristic of alchemy, the sulphur-mercury theory is well illustrated in an engraving of 1617 (Fig. 4). The two kinds of principles or natural exhalations supposed to exist in the interior of the earth are marked with the familiar alchemical symbols for sulphur (left) and mercury (right). They are shown coining into conjunction in the... 

The view of the sulphur-mercury theory as a union of masculine and feminine principles found an expression in various pictorial representations of the so-called Hermetic Androgyne, Rebis, or Two-Thing. These designs, like so many others in alchemy, were often delicately coloured for example, the masculine and feminine half-figures of the hermaphrodite standing beside the sun-trcc (yellow) and moon-trec (blue), signified multiplication and a dragon at the foot represented the liquid menstruum. 

The sulphur-mercury theory of metals has already been discussed (p. 15). 

The Jabirian theory of the formation of metals was clearly based on the views of Aristotle but included a significant new idea. Aristotle had considered metals to be formed by the combination of moist and dry exhalations, and in the Jabirian works these exhalations are identified with the vapours of mercury and sulphur. The cause of the different metals was the different quality of the sulphur from which they were formed. We must beware of identifying the sulphur of the Islamic alchemists with the pure material that we know by that name. The term sulphur probably embraced a whole range of sulphurs of varying purity and colour, and when used as a component of metals probably referred to a volatile combustible material to which no known substance corresponded exactly. Likewise mercury as we know it may only have been considered an approximation to the other volatile liquid component of metals. The sulphur-mercury theory is extremely important in the history of chemistry. The notion that metals contained a combustible principle persisted, and in European chemistry provided the inspiration for the phlogiston theory. 

Rhases adopted the sulphur-mercury theory of metals, and also believed in the possibility of transmutation, but it is clear that he was a very knowledgeable practical chemist. He described the preparation of caustic alkalis by treating sodium or potassium carbonates (obtained by leaching ashes) with slaked lime. Our word alkali comes from the Arabic al-Quili, meaning calcined ashes. The caustic alkalis, along with acidic solutions such as vinegar, sour milk and lemon juice, were known as sharp waters, 2mA were widely used as solvents. Rhases drew up... 

In the thirteenth century, alchemical and scientific theories learned from the Arabs were incorporated into the encyclopaedias written by men such as Vincent of Beauvais (1190-c. 1264) and Albertus Magnus (1193-1280). These writers accepted the Aristotelian elements and the sulphur-mercury theory of the Arabs. They believed that transmutation was a possibility, but that it was very difficult to achieve. Albertus Magnus clearly doubted that a successful transmutation had ever been performed. These books acted as the starting point for many later European alchemists. 

Paracelsus made an important contribution to chemical theory. He extended the sulphur-mercury theory of the Islamic alchemists by adding a third principle, namely salt. Thus, when wood burned, the combustible component was identified with sulphur, the volatile component with mercury and the ashes that remained with salt. The composition of all substances could be expressed in terms of these three principles, or tria prima. As in the previous theories, sulphur, mercury and... 

The tria prima was the brainchild of the Swiss physician, philosopher and alchemist Theophrastus von Hohenheim, best known as Paracelsus (1493-1541). According to Paracelsus s mature theory, all matter was comprised of Salt, Sulphur and Mercury [2]. His idea was clearly an extension and augmentation of the medieval alchemical theory of Sulphur and Mercury, which has been referred to in the previous chapter. Paracelsus modified the Sulphur-Mercury theory in two major ways by adding a third principle, Salt, and by expanding it beyond metals. The three principles came to constitute the building blocks of aU beings in the universe. 

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