How Pliny Became a Grimoire

The transmission is the interesting part. Solinus excerpted him in the third century, Isidore of Seville worked from him, medieval encyclopaedias and lapidaries and herbals mined him steadily, and by the time Renaissance magical texts were being compiled a great deal of their content had reached them through that chain at two or three removes. The virtues attributed to particular stones, the amulets, the plant remedies gathered at particular hours, the whole principle that things which resemble one another act on one another: much of that reaches the grimoires as Pliny material, stripped of the scepticism he attached to it.

That is the irony worth recording. He set out to document credulity and produced the reference work that sustained it, because a hostile description is still a description and copyists keep the recipe and drop the objection. The atlas cites him constantly for that reason and cites him with care, since he is reporting what was believed rather than what was true. He died in the eruption of Vesuvius in 79, having taken ships toward the shore both to observe the phenomenon and to take people off, and the account of it comes from his nephew, who was watching from across the bay.