Tin

## Tin Tin

**Tin** (Lat. *stannum*; alchemical symbol ♃) is the metal of Jupiter, associated with expansion, beneficence, and a silvery-white luster. In medieval alchemical theory, tin was understood as an imperfect metal, closer to silver than to lead but still suffering from impurities in its Sulphur that prevented it from achieving true nobility. Its relatively low melting point, its softness, and its tendency to form a dull oxide coating were interpreted as signs of its imperfection. Yet tin's usefulness in alloys—particularly bronze (copper-tin) and pewter (tin-lead)—and its role in tinning (coating other metals with tin to prevent corrosion) gave it practical importance in metallurgy and alchemy.

The "tin plague" or "tin pest"—the transformation of white tin into gray, powdery tin at low temperatures—was observed by medieval and early modern metallurgists, though not fully understood. This dramatic change in tin's physical properties seemed to demonstrate that metals could undergo radical transformations in their nature, supporting alchemical theories about metallic mutability. Tin was also used in the preparation of various alchemical compounds, including tin salts and tin amalgams. The "Jupiter tree" or "arbor Jovis," a dendritic crystal formation produced by precipitating tin from solution (similar to the silver "tree of Diana"), was regarded as evidence of the vegetative or generative power inherent in metals.

Some alchemical texts describe tin as particularly amenable to "whitening" or "perfecting" into silver, suggesting that it was closer to the perfect state than other base metals. George Starkey's notebooks, analyzed by William Newman, reveal experiments with tin aimed at extracting its "philosophical mercury" or preparing it as an intermediate in transmutational processes. Modern chemistry recognizes tin (Sn, atomic number 50) as an element with two allotropic forms (white tin and gray tin) whose transformation is indeed temperature-dependent, explaining the historical observations of "tin plague." The metal's symbolic associations—with Jupiter, with expansion and growth, with beneficent influence—made it a positive symbol in alchemical allegory, representing the generous, expansive aspect of the work and the capacity of matter to be improved and elevated toward perfection.

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