encre ferrogallique

Ingredients

acide gallique, noix de galle, fer (II), vitriol, manganèse, cuivre, zinc

Preparation Steps

Original Recipe Text

The ink is described as the product of a reaction between gallic acid (extracted from gall nuts/noix de galle (p. xxii, note 9)) and iron (II). The iron component is found in various forms but primarily as vitriol (p. xxii). Vitriol is a mixture of hydrated metallic sulfates including iron sulfate, copper sulfate, manganese sulfate, and zinc sulfate (p. xxxiii). The study notes that iron-gall inks in the corpus were often made by mixing other iron-containing components with gallic acid rather than strictly vitriol (p. xxxiii). A 'Fingerprint model' or 'Signature' is used to compare inks based on the ratios of Mn, Cu, and Zn normalized to iron (p. xxv).

Evidence

"L’encre ferrogallique est le produit d’une réaction entre de l’acide gallique (obtenue à partir de noix de galle), et du fer (II), que l’on peut retrouver sous différente forme mais principalement sous la forme de vitriol dans les recettes contemporaines. (p. xxii)"

Remarks

The study analyzed a corpus of 391 shelfmarks (498 documents) from the 11th century (994-1057 AD), primarily produced by five scribes: Éphraïm b. Shemariah, Yefet b. David, Elḥanan b. Shemariah, Abraham b. Sahlān, and Sahlān b. Abraham (p. xxi, 2). Iron-gall ink was found to be used almost systematically by the Karaite community (p. xxviii). For the Palestinian community, there was a tendency to use iron-gall ink on parchment for religious rolls, whereas the Babylonian community used a variety of inks on leather (p. xxviii). Statistical analysis (multinomial regression) suggests that ink choice for private and legal documents was often dictated by immediate availability rather than community-specific codes (p. xxvii).