Category Archives: Minerals

Cipriano Piccolpasso’s Recipe for the Transmutation of Matter

By Steve Wharton

Cipriano Piccolpasso, Tav. 20, illustrations associated with the making of ‘lustres’, I Tre Libri Dell’Arte Del Vasajo… (1556-75), Dallo Stabilimento Tipografico, 1857.

Certain recipes can tell us a great deal about the cultural and sometimes the technological contexts within which they were compiled and disseminated. In his mid-sixteenth century Italian treatise, the Three Books of the Art of the Potter.., Cipriano Piccolpasso (1523-79) discussed and illustrated the technology and the manufacturing processes that were central to the making of tin-glazed earthenware pottery.[1] Frequently described as having been produced between the years 1556 and 1558, though revised throughout his lifetime, and as an instruction manual, the manuscript was unpublished until the mid-nineteenth century.[2] Today, it is considered the authentic voice of the sixteenth-century Italian potter. However, as I have discussed elsewhere, Piccolpasso’s descriptions are based on observation of the techniques and processes employed by the potters of Castel Durante, rather than practice. Nevertheless his treatise is consistently and frequently cited in highly technical physical and chemical analyses of Renaissance glaze and related technology.[3] The recipes discussed include those for colour as well as those for ‘ruby’ and ‘gold’ lustres: that is the addition of pristine metallic surfaces to otherwise finished ware. Piccolpasso says of them: ‘…I do not intend to go on further until I have discoursed to you upon gold maiolica, from what I have heard of it from others, not that I have ever made it or even seen it being done. I do know that it is painted over finished wares…’

While Piccolpasso is passing on hearsay, he nevertheless includes a recipe for what he calls Rosso da Maiolica [red maiolica]:

A            B

Red earth                           oz           3             6

Armenian Bole                 oz           1             0

Ferretto of Spain             oz           2             3

Cinnabar                            oz           0             3

to which he adds: ‘…with this last mixture ‘B’, include a calcined silver carlino [a burnt coin]’. In his marginal notes he confirms that ‘…this last mixture “B” is called golden maiolica’.

The inclusion of particularly cinnabar is at first a mystery; it has no function in a recipe such as this. It is only when we know that cinnabar is a compound of mercury and sulphur and that all the ingredients are ground together in a pot of red [i.e. strong] vinegar, one of the ‘sharp waters’ employed by alchemists, that things begin to make a little more sense. During the period, what were described as the ‘arts of fire’, which included the making of pottery, were also used to make not only high status bronze-cast sculpture and gold-cast jewellery, for example, but also to manufacture and prepare more ubiquitous substances such as pigments and other colouring agents for an array of manufacturing techniques. These included easel and fresco painting, tesserae for mosaics, fabric dyes and the decoration of glass and indeed pottery. As has been observed, alchemy, in terms of practical chemistry, was primarily concerned with the making of industrial products by using chemical processes; it was not necessarily concerned with the occult, the mystical or the spiritual.[4]

What Piccolpasso described was and is still known as a ‘transmutation lustre’ [my emphasis] in which a paste based upon raw clay is applied to the surface of a pot. It is a well-known technique: the fifteenth-century Hispano-Moresque potters used a red ochre clay corresponding exactly to that included in this recipe. A silver salt was added, in the form of a calcined carlino, together with a copper compound, known as Ferretto of Spain, to produce ‘gold’ lustre. No gold was ever used and in that sense it is the perception of gold that becomes significant.

The transmutation of base material into gold, however, was central to one of the alchemists’ most important aims, and mercury, sulphur and ‘sharp water’ were all part of the process. In his discussion of this recipe, Piccolpasso may well have been relying on what he knew of the presence of alchemy in all kinds of chemical and physical practice, including the production of gold maiolica. More specifically, he raises the question: to what extent might the potters of north-central Italy, in employing their own art of fire, be considered alchemists? What is more certain is that the philosophy associated with alchemy provides an insight into the ways in which knowledge and what kinds of knowledge were gathered and transmitted during the period. Ultimately, Piccolpasso’s record of what he understood as the recipe for ‘gold’ lustre reflected the endeavours of contemporary scholars and indeed pottery practitioners to cope with the challenges of defining and connecting all the different kinds and parts of knowledge that were circulating at that time.


[1] Piccolpasso, Cipriano, Li tre libri dell’arte del vasaio nei quai si tratta non solo la pratica, ma brevemente tutti gli secreti di essa cosa che persino al dè d’oggi è stata sempre tenuta ascosta…ecc., National Art Library, Victoria and Albert Museum, South Kensington, London, MSL/1861/7446

[2] Caiani, A., 1857, I Tre Libri dell’Arte del Vasajo, Roma, dallo Stabilimento Tipografico, Via del Corso, num. 387.

[3] See, for example, G. Padeletti, G. M. Ingo et al, ‘First-time Observation of Maestro Giorgio Masterpieces by Means of non-destructive Techniques’, Applied Physics. A, Materials Science & Processing, 0947-8396, Padeletti, 2006, vol. 83 issue, 4, pp. 475-483; B. Brunetti et al., ‘Copper in Glazes of Renaissance Luster Pottery: Nanoparticles, Ions and Local Environment’, Journal of Applied Physics, 93/12, 2003, pp. 10058–63

[4] A. Y. Al-Hassan, Studies in al-Kimya’, 2009, p. 8; see also L. Abraham, A Dictionary of Alchemical Imagery, 1998, p. 11.

Gumpowder? A strange little recipe for sensitive teeth…

If you go to your bathroom and check the ingredients in your well-known brand of sensitive toothpaste, you may well find that the recipe contains the active ingredient potassium nitrate. Also known as saltpetre or nitre, this naturally occurring mineral is found in foods as a preservative (e.g. corned beef), and used in fertilizer, cigarettes, blood pressure medicines and fireworks. Since medieval times it has formed one of the main ingredients in gunpowder, and it is this connection that has also given potassium nitrate a long association with teeth and gums.

Many of the seventeenth and eighteenth century recipe books in the Wellcome Library’s manuscripts include treatments for gunpowder burns, but some also proposed that gunpowder could be therapeutic. Katherine Jones, Lady Ranelagh (sister to the famous chemist Robert Boyle), recommended a ‘little gunpowder’ applied in a linen cloth to ease toothache. On one page of Anne Brumwich’s recipe book (Wellcome MS 160, p.83) we can find nine recipes for toothache remedies written in two different hands. One, ‘An aproved medecine for ye toothake’ (approved meant that it worked) required gunpowder, aniseed water and lint, mingled together to ‘make a litell thing’.

Once the sufferer had picked their tooth very clean, the recipe instructed them to push the preparation into the tooth, taking care not to allow any of the mixture down the throat.

A century later, in A Treatise on the Scurvy (1795) David Paterson introduced his fellow naval surgeons to a wonderful, and apparently unknown remedy for scurvy: during a voyage in 1784, he claimed, he had restored the health of eighty sick seamen not with lemon juice, fresh fruit or vegetables, but with the potassium nitrate extracted from the gunpowder in his ship’s stores. Paterson’s remedy was soon forgotten, until in 1828, a desperate surgeon named Charles Cameron, having used up all his supplies of lemon juice, remembered Paterson’s recipe. Cameron was stranded in the calms near the equator and he was faced with a ship’s hospital full of scorbutic convicts, less than half way through the voyage to Australia. He extracted the nitre from the powder, dissolved some of it in vinegar, and mixed some more with vinegar and lime juice. He also added a little sugar (to taste?!) The effects were ‘miraculous’.

For the Navy, if Cameron was right, this was a money-saving opportunity; nitre was cheap and did not decompose over time. In the following decades surgeons continued to experiment with different remedies for scurvy until, in 1840, the Admiralty decided to perform a large-scale experiment to determine once and for all the best scurvy remedy. Over the next four years the surgeons of sixty ships transporting fifteen thousand convict men from Britain and Ireland to Australia received crystallised citric acid, potassium nitrate, and lemon juice. Their instructions clearly forbade the surgeons from trying to cause scurvy during the voyage but if the disease did appear, the patients were to be divided into three groups, each group receiving one of the remedies. Of course, the surgeons often had their own ideas, and often altered, combined and varyed the doses according to their own personal favoured recipe. So, while Surgeon Deas mixed some nitre with lime juice and some with citric acid, and felt that both mixtures were useful, Alexander Bryson gave each group the remedies mixed in a glass of wine, water and sugar. After many of the convicts developed severe scurvy, Bryson finally decided that potassium nitrate was ‘objectionable’. The surgeons had come to very different conclusions about the value of potassium nitrate but the results of the experiment were clear; potassium nitrate was abandoned as useless, lemon juice was in for good.

In the mid 1970s, dental researchers – in laboratories this time, rather than on ships – began to report a strange occurrence: mixing potassium nitrate with toothpaste seemed to reduce dental sensitivity in sufferers.  More work confirmed the compound’s beneficial effects, but the scientists still admitted that they were unclear why it should work; being soluble, it seemed that it should simply dissolve in water and wash out of the teeth at first rinse.

Jump forward again to the present, and potassium nitrate is often used as the active ingredient in products for sensitive teeth. So we have come a long way in medical understanding since women like Anne Brumwich stuffed aching teeth with gunpowder soaked lint, or Victorian naval surgeons dosed their convicts with nitre in the certainty that it helped with scurvy, and yet nitre has proved persistent: these earlier ideas about potassium nitrate’s ability to reduce not only the pain of toothache, but the symptoms of scurvy – a disease so commonly experienced in the mouth and gums – are worth wondering about.


Katherine Foxhall is a Wellcome Postdoctoral Researcher in History at King’s College London. Currently working on a history of migraine, Katherine has worked in the past on the history of migrant health, maritime quarantine, and illnesses including scurvy, cholera and typhus. Her book, Health, Medicine and the Sea: Australian Voyages, c. 1815- 1860 has recently been published with Manchester University Press.