Alchemy

What it is

The art of transformation: the attempt to transmute base metals into gold, to produce the philosophers' stone, and to prepare an elixir conferring health and long life.

Its practitioners called it chymistry, and the word covered what we would now separate into chemistry, metallurgy, pharmacy and a philosophy of matter.

The theoretical basis: all metals are composed of the same underlying principles in different proportions and states of maturity. Nature makes gold slowly in the earth; the alchemist attempts to do the same in a vessel, faster.

Where it came from

Graeco-Egyptian. The earliest substantial figure is Zosimos of Panopolis (c. 300 CE), whose surviving writings combine practical instructions for apparatus and processes with allegorical dream-visions of dismemberment and reconstitution.

Islamic. The tradition's greatest expansion. Jābir ibn Ḥayyān and al-Rāzī developed laboratory practice, apparatus and classification systems of real sophistication, and produced genuine chemical knowledge — distillation, sublimation, crystallisation, and the mineral acids that transformed what was possible. Much European alchemical vocabulary is Arabic: alcohol, alkali, alembic, elixir, and al-kīmiyāʾ itself.

Latin Europe from the twelfth-century translations onward, developing through Paracelsus in the sixteenth century into iatrochemistry — the preparation of chemical medicines, which is one of the direct ancestors of modern pharmacology.

How it is practised

In a laboratory, with furnaces, and at length. Processes named for colour changes and stages — nigredo, blackening; albedo, whitening; rubedo, reddening — track observed transformations in actual vessels.

The literature is deliberately obscure. Alchemists used Decknamen, cover-names: one substance called by the name of another, processes described as marriages, dragons, kings and green lions. This was partly protective of commercial secrets, partly a filter against the unworthy, and partly because the tradition held that understanding had to be earned.

And this is where a two-hundred-year misreading began.

What we can and cannot say

We can say alchemy was primarily practical, and the historians settled it by doing the experiments.

The nineteenth century produced a different account. Mary Anne Atwood (1850) and Ethan Allen Hitchcock independently argued that alchemy had never really been about metals at all — that the laboratory language was allegory for inner transformation, and the true work was on the soul. Carl Jung took up this reading in Psychology and Alchemy (1944), interpreting alchemical imagery as projections of the individuation process, and it is Jung's version that most people now encounter.

Lawrence Principe and William Newman dismantled it. Working from manuscripts, laboratory notebooks and the recipes themselves, they showed that alchemical texts describe real operations with real substances — and demonstrated it by reproducing them. Principe decoded Decknamen and performed the procedures, obtaining the described results, including the famous "philosophers' tree", a dendritic growth of silver from an amalgam that alchemists reported and modern readers had assumed was symbolic.

Their historical argument is that Jung read alchemy through Atwood and Hitchcock's already spiritualised lens, and that the strong spiritual-allegory reading is a Victorian construction projected backwards onto people who were doing chemistry.

We can say the practical achievements were substantial. Mineral acids. Distillation apparatus and technique. The isolation of phosphorus by Hennig Brand in 1669, from a great deal of urine, in search of the stone. Antimony and zinc compounds. The whole apparatus and vocabulary that early modern chemistry inherited.

We can say the practitioners were not marginal. Isaac Newton left roughly a million words of alchemical manuscripts and spent decades on it. Robert Boyle, whose Sceptical Chymist is a founding text of chemistry, pursued transmutation and lobbied to have the law against it repealed. This was not a fringe pursued by cranks; it was what serious natural philosophers did.

We can say a religious dimension was genuinely present, and Principe and Newman do not deny it. Alchemists worked in a Christian frame, saw analogies between the purification of matter and of the soul, and some wrote explicitly about both. The correction is about primacy: the chemistry was the work, and the spiritual reading accompanied it rather than replacing it.

We cannot say transmutation occurred. Lead does not become gold by chemical means, for reasons alchemists could not have known — the difference is nuclear, not chemical.

The honest verdict is a reversal of the popular one. Alchemy is usually presented as mystical nonsense that happened to leave behind some glassware. It was substantially an experimental science with a wrong theory, pursued for fifteen hundred years by people including two of the founders of modern physics and chemistry — and the mystical reading of it is younger than the theory of evolution.

Further reading

• Lawrence Principe, The Secrets of Alchemy (2013) — the best single book, including the reproduced experiments.
• William Newman and Lawrence Principe, Alchemy Tried in the Fire (2002).
• Carl Jung, Psychology and Alchemy (1944) — read as psychology, not as history.