From the London Review of Books, Vol. 47 No. 23 · 25 December 2025:
Puffing on the Coals
The alchemist in his laboratory was a popular subject for Dutch painters of the 17th century because it allowed them to show off their skill with light. Mattheus van Helmont’s A Savant in His Cabinet, Surrounded by Chemical and Other Apparatus, Examining a Flask (1670s), one of the splendid plates in Philip Ball’s introduction to alchemy, depicts an alchemist at work, brandishing a beaker of pale blue fluid in one hand, surrounded by the implements of his craft. The room is unkempt: hundreds of glass and earthenware vessels, glinting in the dim window light, are strewn about the floor, along with tatty leather-bound tomes and discarded notepaper. To one side looms the athanor (from the Arabic for oven, at-tannur), a coal-fuelled brick furnace where oils were distilled and metals smelted. Among the flasks, phials and funnels are a number of alembics. The alembic, perhaps the most iconic piece of alchemistic labware, also takes its name from Arabic: al-anbīq refers to the long, sloping neck that protrudes from the instrument’s gourd-like body. It was used for distillation, a stock-in-trade of the alchemists and a process they believed could release the spirit of a substance – the ‘spirit of wine’, for instance, which had medical applications in addition to those for which it’s better known.
A picture of the alchemist’s laboratory from a hundred years earlier – a satirical woodcut by Pieter van der Borcht – depicts the alchemist, his wife and children as apes, surrounded by broken equipment, hopelessly puffing on the coals of their furnaces. In the background, another ape family can be seen at the door of the poorhouse accepting a parcel of food. At a time when alchemy was supposedly in its heyday, the print offers a popular view of the alchemist as a deluded fool, absorbed in his quest for the philosopher’s stone while he and his family sink into poverty. The philosopher’s stone, a mythical substance that could transmute any metal into gold, was the alchemist’s main preoccupation for hundreds of years. In that time, though the stone remained elusive, the alchemical laboratory produced many useful things, including dyes, medicines and porcelain. The recipe for porcelain, which had been imported from China, remained a mystery in Europe until an alchemist at the court of Augustus II, King of Poland, discovered it by accident in 1704 when his clay crucible (containing kaolinite) was transformed by intense heat into white ceramic. In 1669, phosphorus was isolated by a German alchemist, Hennig Brand, who distilled large volumes of urine, believing it to contain the crucial agent of transmutation, until he was left with a soft metallic substance that glowed, ignited in air and gave off a garlicky odour.
Belief in the possibility of chrysopoeia, the artificial production of gold, was based on a theory of the elements first expounded by Empedocles in the fifth century bc and later taken up by Plato and Aristotle. Empedocles proposed that all matter is constituted by the four elements of earth, air, fire and water, and that these elements are not immutable: solid substances could be melted to flow like water, while water could be frozen solid. According to Aristotle, each element possesses two of four distinct qualities – hot, cold, dry and wet (water is cold and wet, fire is hot and dry). One element could be transformed into another by altering its qualities: ‘Water becomes earth (cold and dry) by changing wetness to dryness, and becomes air (hot and wet) by changing cold to hot through heating.’ If an earthy substance could become an airy one, then the transmutation of one metal into another, ostensibly a less drastic change, didn’t seem implausible.
Ball traces the roots of alchemy to the metallurgists of ancient Egypt, who mastered the arts of smelting, bronze-making and iron-working. Papyri containing the trade secrets of fourth-century artisans include instructions for ‘making’ (or faking) silver from copper, and for giving copper ‘the appearance of gold’. Zosimos of Panopolis, a late third-century metalworker from Alexandrian Egypt, also writes of the ‘tingeing’ of metals, which he describes as the transfer of the pneuma (‘spirit’) of one metal to the soma (‘body’) of another. But it was in the work of medieval Arabic alchemists that the art of chrysopoeia acquired a firm theoretical basis, and what we now think of as alchemy took shape.
The eighth-century alchemist Jābir ibn Hayyān (known in English as Geber) claimed that all metals are composed of the same two ingredients in different proportions: sulphur, which is hot and dry, and mercury, which is cold and wet. This was taken as a given by the generations of alchemists that followed, though it’s often unclear whether they meant the elements themselves or something closer to their ‘essences’ (alchemical texts refer to ‘Philosophic Mercury’ and ‘Philosophic Sulphur’). According to Geber, one metal could be transformed into another by altering its proportions of mercury and sulphur to match those of gold. This could be achieved via an elixir, a dry powder that combined mercury and sulphur in the perfect ratio. This elixir came to be known as the philosopher’s stone, or lapis philosophorum, thanks to a Latin text attributed to Geber but probably written by an Italian monk five centuries later. Pseudo-Geber claimed that while certain agents of transmutation could create the appearance of gold, only the philosopher’s stone made the real thing.
The principles behind the philosopher’s stone help to explain some of the more enigmatic alchemical art. An image of Mercurius, a figure symbolising the completion of the alchemist’s work, appears alongside Ball’s commentary on chrysopoeia. In this picture, taken from a Rosicrucian compendium of 1760, Mercurius appears as a three-headed dragon. The first head, a moon with the face of an eagle, symbolises mercury; a second, representing sulphur, takes the form of a cheerful yellow sun; while the third is a sun-moon fusion combining the astrological symbols for mercury and the sun. From the third head protrudes a long beak, grasping the pale tip of the dragon’s tail. The base of the tail is darker, greenish and emerges from a dark blue body that possesses a fourth head, charcoal-black and ugly as a troll’s. There are allusions here to the Ouroboros – the snake that eats its tail, a common motif in alchemical art, signifying the union of opposites – and to the process by which the philosopher’s stone was supposed to be manufactured. For the alchemist’s ingredients to metamorphose into the philosopher’s stone they had to be forced through a series of colour changes: an initial phase, the nigredo, or blackening, was followed by albedo, whitening. In the final phase, rubedo, the stone turned red. Ball, drawing on alchemists’ notebooks and lists of ingredients, makes an educated guess as to what was going on here: lead, when heated in air, forms black, yellow and red oxides. Red lead (lead tetroxide) had been used as a pigment from antiquity.
There are many accounts of the successful fabrication of gold by alchemists, though we can be sure that, at least by the standards of modern chemistry, a transmutation never took place. Ball explains that though there were charlatans who set out to trick people, many alchemists genuinely believed their attempts had worked. For one thing, it was difficult to establish whether what they had produced was real gold. The technique used for verifying gold was an unreliable process known as ‘cupellation’, in which metals were separated from each other by melting and then weighed. If a chunk of putative gold weighed the same after cupellation as it did before, it passed the test. The definition of gold was also unstable. It was widely believed that transmutation could happen in stages – an alchemist could produce a substance that was approaching gold or near enough to gold – and if a metal possessed some but not all the properties of gold, it might be gold but of an inferior sort....
....MUCH MORE
The first named artwork, "A savant in his cabinet..." is in the Wellcome Collection, London, which seems appropriate, Sir Henry Wellcome transmuted pharmaceuticals into a heck of a lot of money.
A bit of history via El Pollo Real:
...Natural transmutation was first discovered when Frederick Soddy, along with Ernest Rutherford, proved that radioactive thorium converted itself into radium in 1901. At the moment of realization, Soddy later recalled shouting out: "Rutherford, this is transmutation!" Rutherford snapped back,
"For Christ's sake, Soddy, don't call it transmutation.
They'll have our heads off as alchemists."
—from a May 2012 post "Climateer Line of the Day: Thorium Edition"
Last seen in August 2025's "AI’s 1930s moment Are we on the brink of disaster?".
