In 1815, Cardinal Angelo Mai made an extraordinary discovery in the Ambrosian Library in Milan. He spotted that a book containing the records of the First Church Council of Chalcedon in ad 451 had been made out of reused parchment. The earlier writing on each sheet had been erased (washing with milk and oat-bran was the common method), and the minutes of the Church Council copied on top. As often in reused documents of this kind, the original text had begun to show through the later writing, and was in part legible.

LRB 23 July 2009 | PDF Download