After the time of St. Patrick, as everything seems to have been written down that was considered worth preserving, Manuscripts accumulated in the course of time, which were kept in monasteries and in the houses of professors of learning: many also in the libraries of private persons. The most general material used for writing on was vellum or parchment, made from the skins of sheep, goats, or calves. To copy a book was justly considered a very meritorious work, and in the highest degree so if it was a part of the Holy Scriptures, or of any other book on sacred or devotional subjects. Scribes or copyists were therefore much honoured. The handwriting of these old documents is remarkable for its beauty, its plainness, and its perfect uniformity; each scribe, however, having his own characteristic form and style. Sometimes the scribes wrote down what had never been written before, that is, matters composed at the time, or preserved in memory; but more commonly they copied from other volumes. If an old book began to be worn, ragged, or dim with age, so as to be hard to make out and read, some scribe was sure to copy it, so as to have a new book easy to read and well bound up. Most of the books written out in this manner related to Ireland, as will be described presently; and the language of these was almost always Irish; except in copies of the Roman classics or of the Scriptures, where Latin was used. Books abounded in Ireland when the Danes first made their appearance, about the beginning of the ninth century; so that the old Irish writers often speak with pride of “the hosts of the books of Erin.” But with the first Danish arrivals began the woeful destruction of manuscripts, the records of ancient learning. The animosity of the barbarians was specially directed against books, monasteries, and monuments of religion: and all the manuscripts they could lay hold on they either burned or “drowned”--_i.e._, flung them into the nearest lake or river. Next came the Anglo-Norman Invasion, which was quite as destructive of native books, learning, and art as the Danish inroads, or more so; and most of the old volumes that survived were scattered and lost.