The "Treatise" is important for the study of Old Norse, as it is a major text showing the state of the language just prior to the writing of the Icelandic Sagas. It also provides a comprehensive study of the pronunciation of the language, to the extent that it created an Icelandic alphabet derived from the Latin, and more adapted to writing on paper or parchment than the older, epigraphic Runic alphabet that was made for shorter carvings on wood or stone. (Other writings in the Latin alphabet presumably existed in the form of law books and Christian writings. The educated clergy of the time would not have used runes.) This alphabet included þ (derived straight from the runes), as well as diacritic indication of vowel length, and an o with an ogonek. The "First Grammarian's" entire system was never adopted, as evidenced in later manuscripts, in some cases not much younger, but it has had an influence on Icelandic writing ever since (see above). See Icelandic orthography.