Many Mordants
While some dismiss these papyri as alchemical in nature, as the introduction notes in the comprehensive translation completed by Professor Earle Radcliffe Caley (our primary reference for this project), to most chemical historians they are considered, instead, the oldest chemical manuscript in the world.
“As a reading of these translations quickly reveals, neither papyrus contains the mystical symbolism and allegorical indirection so typical of the true alchemical literature. Rather they consist largely of simple, short recipes. In the case of the Leyden papyrus these focus primarily on the preparation of various metal alloys – many of which are intended to imitate the appearance of either gold or silver – for use in making jewelry, in gilding, or in metallic writing, while a few others deal instead with dyes of various sorts. The contents of the Stockholm papyrus have the same form, but focus more on dyeing and the imitation of various precious stones and gems. Both papyri explicitly acknowledge that the alloys and gems which they describe are imitations and not the real thing. Indeed, so simple and safe are some of the recipes that they have actually been proposed as potential laboratory preparations for use in connection with a modern-day history of chemistry course. ”
In the sections on methods/recipes related to dyeing, many pertain to various mordanting methods to achieve different results. In many cases, either the method of dyeing that is intended to go with a particular method of mordanting is either assumed (i.e. the reader is expected to just know), or it may have been lost, as there is some indication that the papyri are incomplete. Perhaps the grave robber who stole the papyri from their funerary resting place left some portions behind, or perhaps they had long ago disintegrated.
As a natural dye educator, my students will attest to the primacy I place on effective fibre preparation to achieve excellent results. So the numerous fibre preparation methods in the papyri appeal to me very much, and I chose to focus on two of them. I will describe my approach to the second mordant method in a later blog post.
One of the many challenges we faced in attempting to recreate these methods is terminology. Measures, and even terms for ingredients, have changed over time and, particularly in the case of ingredients, are dependent on the understanding of papyri translators over the last century or so, most of whom had no practical natural dyeing expertise.
We also know that even where we have shared terminology with the scribe(s) who wrote these papyri some 1,700 years ago, such as ‘alum’, the nature of the ingredient has changed over time.
In the previous millennia, the term ‘alum’ described a wide range of naturally occurring minerals with astringent properties, that usually contained some form of aluminum oxide or aluminum sulfate, but often complexed with various forms of iron, other metals, and organic and inorganic non-metals. It was a far cry from the highly purified forms of aluminum salts that we can easily purchase nowadays. However, even though our ancient counterparts did not have access to our highly purified metal salts, they did have a sophisticated understanding of the variable characteristics of alums mined in different geographic regions, and/or with particular qualities. Thus, we see references such as the following.
I spent time researching modern equivalents for the ancient measures noted in this method (and will provide details on how to do the conversions yourself at a later date) and, once I had my metric equivalents, then had to decide how to interpret the ingredient, ‘dross of iron’. My research indicates that it is the materials that float to the surface during the smelting of mined iron ore. This surface ‘dross’ was scraped off and used for other purposes, including as a mordant/modifier in dyeing.
A very ‘milky’ mordant bath.
Again, the variable geology of different regions where iron ore was mined determines the specific metal and non-metal components found in dross. However, some of the studies I read identified a few significant components often found in iron dross, including iron oxide, aluminum oxide, and calcium oxide. As proxies for these components, I used the relevant metals in the form of ferrous sulfate, potassium aluminum sulfate, and calcium hydroxide (calx/slaked lime/pickling/lime).
I followed the method as faithfully as possible, which resulted in a very milky mordant bath, with much of the calcium hydroxide undissolved (it is not very soluble in water), but I moved my fibres regularly to ensure as even exposure as possible to all mordant components.
The resulting wool fibres were beautifully soft and with the tinge of beige/grey we expect from an iron mordant/modifier used in a small quantity.
The shaded area is the Lydian Empire mid 6th century BCE, under the rule of King Croesus (‘rich as Croesus’).
Source: Wikimedia Commons
The name of this method, mordanting for ‘Sardian’ purple, also led me down various fascinating rabbit holes. I learned that Sardis was once a very important centre of trade, in what is now western Turkey, at the crossroads of trade routes between Africa, Asia, and Europe. It was the capital of the Lydian Empire. Under Roman occupation since the first or second century BC (sources vary in the actual year this took place), it was renowned for many traded commodities, including two key dye materials - nitrum (soda ash, used for many things besides natural dye processes), and coccum (kermes). Sardis was, apparently, famous for its scarlet dyed cloth.
As noted earlier, either the method of dyeing intended to go with this particular method of mordanting is assumed (i.e. the reader is expected to just know), or it may have been lost. So, to test the results of this mordant method, I proceeded to make a simple cochineal dye bath. As kermes is no longer readily available, due to over-harvesting/extirpation, I used cochineal as a subsitute, since the active dye compound in both - carminic acid - is chemically identical.
Dye results using cochineal (25% WOF of powdered cochineal in tap water) over wool mordanted ‘for Sardian purple’.
Today, most people would not describe this dye result as ‘purple’, though may see a purple undertone to the iron shifted cochineal. However, historically, ‘purple’ was understood to represent a wide range of hues, from pink-purple to red-purple to blue-purple, so this final colour may very well have been considered a type of ‘purple’ to a dyer in Thebes in the third or fourth century. It’s also possible that the use of actual, impure iron dross, rather than the proxies I used (as described above) - not having access to an iron ore smelting facility - would shift the carminic acid into a more pronounced purple hue.
I’m pleased with the result, either way. I would like to think that a dyer in ancient Sardis might recognize the colour I achieved as being akin to the scarlet for which their city was renowned throughout the ancient world, even if the Theban scribe who penned the papyrus would not recognize it as ‘Sardian purple’.
Or vice versa.
Thank you for your interest in this complicated and fascinating recreation project. I am happy to answer any questions you may have.
Mel Sweetnam, Mamie’s Schoolhouse
Unama’ki (Cape Breton Island), Nova Scotia, Canada