PAIIMMPSEST (weatookiereer, from orate again, and fetes to clout's or rub) is a term applied to a manuscript, from which the original text has been erased, in order to make room for a second subject ; a process which was accomplished by rubbing it with pumice-atone or other similar substances till the traces of the original writing disappeared, and then smoothing it down with a roller or polisher. That this practice was adopted by the ancients, appears from a passage in Cicero's letter to the jorteconsult Trebatius, where he praise. his frioud for having been se economical as to write on a palimpsest, but says that he should like to know whet those things could hare been which were considered of less importance than his letter. (' Ad vii. IS.) Pahimpeests are also mentioned by Plutarch and Catellus, but these appear to have been rather leaver of books, so prepared that one writing could easily be expunged and another substituted,and were frequently need by authors for correcting their works, an is evident from tho satire of Catullus It was not, however, till the 9th or 10th century that this practice became at all general, and then it was more frequently resorted to by the Latins than the Greeks. In the 11th century it appears to have been at its height. In the 13th and 14th centuries edicts forbidding it were issued in Germany ; and it had not entirely ceased in the 15th century : as Kuittel, in his account of the palimpsest manuscripts in the Augustan library at Wolfenbiittel, tells us that in the early times of the art printed books were sometimes worked off on vellum from which ancient writings had been erased, and instances particularly an edition of the Clementine Constitutions, printed by Nicolas Janson in 1476 upon parchment, which had undergone this process of obliteration to prepare it for the purpose.
The earliest observations on palimpsest manuscripts were made in France, iu 1692, by M. Bohan, of the Bibliothaque du Rol, who discovered beneath the Greek text of St. Ephrem, written in the 14th century, a portion of the Greek Bible, in uncial letters of the 6th century. This was followed, in 1755, by a similar discovery made by
F. A. Knittel in the Augustan library at Wolfenbiittel, of a palimpeest manuscript of the Origines of Isidorus, under which was a translation of the Epistle to the Romans, by Ulphilas, bishop of Gothland, who in the 4th century was known to have translated the whole of the Scriptures into the language of that country, and to have invented a new character, consisting of letters borrowed chiefly from the Greek for that purpose, but of wholie labours only the four Gospels were previously known to exist in the Coder Argentots at Upsala. In 1762, Knittel published, in 4to, the greater portion of the missing volume, which, although not identical with the Codex A rgentens, as originally supposed, proved to be a portion of a similar manuscript.
By far the greatest discoveries in the field of palimpsest manuscripts were, however, made by Cardinal Mai. In his researches in the Ambrosian library at Milan, of which he was keeper, he discovered several fragments of Cicero's orations; these comprised the orations against Clodius and Cnrio, that ' De :Ere alieno klilonis,' not pre viously known, and the oration Do Rego Ptolemreo.' These treasures had lain concealed for centinies under a Latin translation of the Acts of the Council of Chalcedon, and were adjudged by the discoverer to belong to the 4th century. In another manuscript ho detected several fragments of the orations of Symmachus, who bad previously been known only from his epistles; and the whole of the comedies of Plautus, including a fragment of the ' Vidularia,' a lost comedy, of which all that previously existed. were twenty lines, preserved by Priscian and NODillS.
Being promoted to the librarianship of the Vatican, lie discovered in that library the treatise of Cicero,' Do Republice; of which nothing had been known, in modern times, beyond the fragments preserved in the writings of Macrobius, Lactantiue, Augustin, Nouius, and others. This priceless manuscript came from the celebrated Abbey of St.