The books of saga, poetry, and annals that have come down to our day, though so vastly more ancient and numerous than anything that the rest of Western Europe has to show, are yet an almost inappreciable fragment of the literature that at one time existed in Ireland. The great native scholar O'Curry, who possessed a unique and unrivalled knowledge of Irish literature in all its forms, has drawn up a list of lost books which may be supposed to have contained our earliest literature. We find the poet Senchan Torpéist--according to the account in the Book of Leinster, a manuscript which dates from about the year 1150--complaining that the only perfect record of the great Irish epic, the Táin Bo Chuailgne[1] or Cattle-spoil of Cooley, had been taken to the East with the Cuilmenn,[2] or Great Skin Book. Now Zimmer, who made a special and minute study of this story, considers that the earliest redaction of the Táin dates from the seventh century. This legend about Senchan--a real historical poet whose eulogy in praise of Columcille, whether genuine or not, was widely popular--is probably equally old, and points to the early existence of a great skin book in which pagan tales were written, but which was then lost. The next great book is the celebrated Saltair of Tara, which is alluded to in a genuine poem of Cuan O'Lochain about the year 1000, in which he says that Cormac mac Art drew up the Saltair of Tara. Cormac, being a pagan, could not have called the book a Saltair or Psalterium, but it may have got the name in later times from its being in metre. All that this really proves, however, is that there then existed a book about the prerogatives of Tara and the provincial kings so old that Cuan O'Lochain--no doubt following tradition--was not afraid to ascribe it to Cormac mac Art who lived in the third century. The next lost book is called the Book of the Uacongbhail, upon which both the O'Clerys in their Book of Invasions and Keating in his history drew, and which, according to O'Curry, still existed at Kildare so late as 1626. The next book is called the Cin of Drom Snechta. It is quoted in the Leabhar na h-Uidhre, or "Book of the Dun Cow"--a MS. of about the year 1100--and often in the Book of Ballymote and by Keating, who in quoting it says, "And it was before the coming of Patrick to Ireland that that book existed,"[3] and the Book of Leinster ascribes it to the son of a king of Connacht who died either in 379 or 499. The next books of which we find mention were said to have belonged to St. Longarad, a contemporary of St. Columcille. The scribe who wrote the glosses on the Féilĭrè of Angus the Culdee, said that the books existed still in his day, but that nobody could read them; for which he accounts by the tale that Columcille once paid Longarad a visit in order to see his books, but that his host refused to show them, and that Columcille then said, "May your books be of no use after you, since you have exercised