Fiat Lux ... how Alessandro Volta illuminated his scripts

Abstract

The ink used by Volta in his scripts appears to be a very complex mixture. Our analysis of the eluates from the EVA diskettes (via GCXGC/TOFMS) has revealed the presence of more than 1800 unique metabolites. The ink thus appears to be a very complex combination of different ingredients, mainly consisting of tannins, vegetable oils and resins together with root and wood dyes. In particular, the presence of hydroxy and dihydroxyanthraquinones, as well as natural quinoids, evidenced the use of madder dyes from Rubiaceae as an important component of this ink. Natural quinoids, based on a 9, 10-anthraquinone skeleton, hydroquinone and anthrone derivatives, and even the specific marker of alizarin, indicate the use of the Rubia tinctorum. Additionally, the presence of several signals of fatty acids, saturated and unsaturated mono and dicarboxylic acids, as well as of the typical signals of Pinaceae resins substantiated the use of a vegetable oil and colophony. Several signals of cyclic monosaccharides suggested also the use of natural gum (Acacia Senegal also known as Arabic gum). It is known that Arabic gum, as well as linseed oil, were often employed as thickeners to increase the viscosity of the ink and to protect it from excess absorption of atmospheric oxygen. Curiously, we also found characteristic signals from alkaloids such as Dioncophyllin A and B, typical metabolites from tropical/exotic plants such as Triphyophyllum, Habropeltatum and Dioncophyllum. To our reckoning such an extensive array of ingredients in inks adopted over millennia has never been reported.

Keywords

• Plant metabolites
• Ink components
• GCxGC–TOFMS
• Manuscripts characterization
• EVA extraction
• Non-invasive analysis