<p style='text-align: justify;'>In his famous alchemical text, <i>Compound of Alchemy</i> (1471), George Ripley (died c. 1490) made use of a complex alchemical image ' the 'Wheel' ' to convey the subtleties of his art. The quadripartite wheel, composed of concentric spheres with captions and verses, embodied a variety of sophisticated alchemical ideas and procedures, and was therefore an important visual reference for the reader of the <i>Compound</i>. Within its concentric spheres, the <i>Wheel</i> tabulated information about a variety of natural philosophical and alchemical phenomena. The four Aristotelian elements and their qualities are incorporated, along with the compass points, seasons, dimensions, signs of the zodiac, and medical virtues. Other more specifically alchemical detail was also provided, such as the four metallic bodies used in Ripley's alchemy (the Sun, Moon, Venus and Mercury, equating to gold, silver, copper, mercury), along with the proportions of each to be used in alchemical preparations, while the three inner circles included the names of colours and primary and secondary qualities associated with various stages of metal transformation. By representing this information in the form of a circular diagram, Ripley's <i>Wheel</i> could also be used to explain alchemical transformations. For instance, circular forms were familiar tropes used to denote the 'squaring of the circle' ' the transformation of the four Aristotelian elements. Through the substitution of their primary qualities, the elements were considered transmutable, such that Earth (cold and dry), could become Water (cold and moist), by losing its dryness; Water could become Air (hot and moist) by yielding to heat. Since elements could not transform into their contraries without an intermediate step, this process was cyclical, and thus the wheel was an appropriate device to indicate this process. Similarly, the wheel was an appropriate analogy for the transformation of metals, whereby a metal could be 'rewound' to an earlier state, and then built up once more to a purer form; according to this theoretical framework, base metals could be transformed into gold through a series of rotations of the wheel. By thus presenting his information in circular form, Ripley's <i>Wheel</i> is simultaneously a sophisticated visual manifestation of alchemical doctrine and a digest of the various transformations detailed in his <i>Compound</i>. Furthermore, the design of the figure, featuring an inner circle nested in a series of concentric spheres, is highly reminiscent of cosmological diagrams of the period, and represents a perceived connection between the celestial and terrestrial realms. While elements could be divided and transformed into one another, they could also, through repeated cycles of transitions, produce a fifth element of celestial perfection ' the quintessence or 'Philosophers' Stone'. This 'circling of the square' was a well-established alchemical doctrine by the late fourteenth century and reflects the common designation of alchemy as 'terrestrial astronomy'. Though no fifteenth-century version of the figure survives, numerous sixteenth- and seventeenth-century manuscripts testify to the complexity of the design, while later printed editions of the <i>Compound</i> also include variations of the <i>Wheel</i>. This image is from the 1591 English edition of the <i>Compound</i>, printed by Thomas Orwin. The transition of the figure into print has entailed a loss of detail compared to manuscript versions, perhaps reflecting the difficulty of accommodating all the elements of this complex figure into a single printed sheet. For instance, in this version, the captions from the inner spheres, present in the earliest manuscript copies, have been omitted; thus the diagram offers no practical guidance in terms of correct proportions of alchemical substances. Furthermore, while the original diagram assigned the outer spheres to the four metallic bodies (Sun, Moon, Venus and Mercury), this version of the <i>Wheel</i> both omits Venus and superimposes a conventional cosmological scheme onto the diagram, adding the symbols of the seven planets, from the Moon to Saturn, to the respective concentric circles. The coexistence of these two planetary schemes renders both unclear: the outer ring now contains both Saturn and the Sun; Jupiter shares a sphere with the Moon; Mercury has intruded into the realm of Mars. Though the origin of these changes from the original diagram is unknown, it could reflect a decision to bring Ripley's alchemical orbits in line with 'correct' astronomical order.</p>
