soot

Ingredients

soot, lead (II) acetate, water

Preparation Steps

Original Recipe Text

The ink is primarily carbon-based (soot) but contains significant concentrations of lead, detected at 11–21 μg/cm2 in one case and 79–89 μg/cm2 in another (p. 67-68). Hypotheses for the recipe include intentional addition of lead (II) acetate as an additional pigment or as a drying agent to accelerate the process (p. 67).

Evidence

"Recent analyses carried out on some fragments of Herculaneum papyri by synchrotron X-ray-based techniques have shown the presence of lead (in a state similar to lead (II) acetate) within the ink (p. 67)."

Remarks

The discovery of lead challenges the communis opinio that Herculaneum ink was exclusively carbon-based (p. 67). Lead serves as the best element for discriminating between ink and writing support in these carbonized fragments (p. 68). The concentration of lead detected is too high to be accidental contamination from water or containers (p. 67-68).