London. British Library, ms. Cotton Nero A.VII, fol. 41r. Courtesy of the British Library
Digitized Manuscripts.
The Mappae Clavicula is a medieval Latin text detailing techniques for creating materials used in art creation. Recipes from the Mappae Clavicula are evidenced in thirty-seven manuscripts, most often present alongside other art recipe works from between the ninth and twelfth centuries such as the Compositiones Variae, De coloribus et artibus Romanorum, and Schedula diversarum artium. All of these build upon an art material manufacturing tradition evidenced in older treatises in Greek, primarily from Alexandria in the very early Middle Ages, as well texts such as Papyrus Gracus Holmiensis and the "Leyden Papyrus X."
The Mappae Clavicula's foliation within evidenced manuscripts is inconsistent, with the selected extracts varying significantly between attestations (for example, Compositiones Variae, also called Compositiones ad tingenda, only draws from the Mappae Clavicula's dye recipes) and the recipes usually appears in small segments rather than as a larger, distinct text, befitting the Mappae Clavicula's nature as a series of short, often one-sentence directions. It is better to think of the Mappae Clavicula as a very loose framework for a set of widely-known art recipes, rather than a concrete body of recipes.
Rozelle Parker Johnson was a scholar on Medieval and Classical recipes for creating art materials, who was primarily focused on the Mappae Clavicula. Johnson completed his doctoral dissertation under Oldfather at UIUC in 1932 on the Compositiones varie from Biblioteca Capitolare, Luccan Codex 490, and published a revised and expanded version of it in 1939 as a book, integrating studies of a multitude of Mappae Clavicula manuscripts into his analysis. Johnson wrote prolifically on the Mappae Clavicula, and, after finishing his studies at UIUC, worked as a lecturer and researcher at the University of Vermont and Brown University, and eventually became an associate professor of Latin at the University of North Carolina at Chapel Hill in 1937. He was killed in a car accident in 1942, less than a decade after completing his doctoral dissertation and just over four years after beginning his work as a professor.
While Oldfather did not make his Mappae Clavicula manuscript photostats for Johnson specifically, Johnson did make use of them in his research, and ordered additional photostats of other Mappace Clavicula manuscripts himself.
A full list of Johnson's publications on the Mappae Clavicula is below, as well as one additional publication.
Higlight if digitized.
---. "The Compositiones ad tingenda." Technical Studies in the Field of Fine Arts, vol. 3, no. 4, 1 Apr. 1935, pp. 220-236.
---."Compositiones variae, from Codex 490, Biblioteca capitolare, Lucca, Italy, an introductory study." University of Illinois Press, 1939. Illinois Studies in Language and Literature, vol. 23, no. 3. HathiTrust Digital Library. Also available in the Main Stacks. Johnson's 1932 doctoral dissertation in its rereleased form.
