In her article discussing memory in The Last Man, Lisa Hopkins discusses the following passage from 'The Mortal Immortal':

All the world has heard of Cornelius Agrippa. His memory is as immortal as his arts have made me. All the world has also heard of his scholar, who, unawares raised the foul fiend during his master's absence, and was destroyed by him. The report, true or false, of this accident, was attended with many inconveniences to the renowned philosopher.

Hopkins declares:

This passage begins by piquing the reader's curiosity. In the classic marketing ploy of fiction from Defoe onwards, it claims a place in discourses of the famous: 'All the world has heard of Cornelius Agrippa.' We are further titillated by being introduced to someone who actually knew the great man - and then abruptly let down when the eye-witness turns out to be unable to confirm or deny the truth of the most famous anecdote about Agrippa. This is, we are soon afterwards told, because, like Raphael when Adam has to tell him about the creation of mankind, Winzy was elsewhere at the crucial moment. However, though the famous story must remain unconfirmed, a lesser-known, but equally sensational one can be unfolded in its place . . .

[link to the full text of Hopkins' article in Romanticism On the Net 6 (1997)]