art from k (c), and that the final
syllables have not disappeared (cf. _maqqi_, O. Ir. _maicc_), but it
appears certain that in Ogamic writing stereotyped forms were used long
after they had disappeared in ordinary speech. Several stones contain
bilingual inscriptions, but the key to the Ogam alphabet is supplied by
a treatise on Ogamic writing contained in the Book of Ballymote, a
manuscript of the late 14th century. It should be mentioned that the
Welsh stones are early whilst the Scottish ones are almost without
exception late, and several of the latter have so far defied
interpretation. In addition to the Irish Ogams there are a number of
Christian inscriptions in Latin character, but, with one exception, they
are not older than the 8th century.

See R.R. Brash, _The Ogam Inscribed Monuments of the Gaedhil_ (London,
1879); R.A. Stewart Macalister, _Studies in Irish Epigraphy_ (London),
vol. i. (1897), vol. ii. 1902, vol. iii. 1907. The Welsh inscriptions
are contained in J. Rhys, _Lectures on Welsh Philology_[2] (London,
1879). The Scottish stones have also been treated by Rhys in the
_Proceedings of the Scottish Society of Antiquaries_ (Edinburgh,
1892). See also G.M. Atkinson for the tract in the Book of Ballymote,
_Kilkenny Journal of Archaeology_ (1874). The Irish Christian
inscriptions were published by Margaret Stokes as the annual volumes
of the Roy. Hist, and Archaeol. Association of Ireland (1870-1877),
and have been republished by R.A. Stewart Macalister.

(a) _Irish._--We are able to trace the history of the Irish language
continuously for a period of 1200 years, and from the time that the
literary documents begin we are better supplied with linguistic material
for the study of the language than is the case with any other Celtic
dialect. At the same time that form of Irish which is to be found in the
oldest documents has preserved a number of features which have entirely,
or almost entirely, disappeared from the Brythonic languages. For this
reason scholars have largely occupied themselves with Irish, which for
purposes of comparative philology may be regarded as the classic Celtic
language.

The history of Irish is divided into three periods:--Old Irish
(700-1100), the documents mainly representing the language of the 8th
and 9th centuries; Middle Irish, extending roughly from 1100 to 1550;
Modern Irish from 1550 to the present day. These periods merge into
one another