A manuscript containing poetry of Bedo Brwynllys, Dafydd ap Gwilym, Guto'r Glyn, Huw Cae Llwyd and others (pp. 1-136, 149-159); a vocabulary (pp. 137-149); Dafydd Ddu [Hiraddug]'s Grammar (pp. 161-198); the statutes of Gruffydd ap Cynan (pp. 199-206 (at the end of this extract is the note 'Dyma y maint a gebhais o'r Statut yn lhybhyr Meistr Sion ap Edward gam o drebh newydd, o blwybh Dewi yn Sir bhracheiniog . 1579 .'); a translation into Welsh of Genesis I (pp. 230-245); Biblical extracts and history (pp. 246-264) (a note on p. 252 records that the Biblical extracts were taken 'o lybhyr Mr Edmond Morgan o Bhedwelhty'); &c. All but pp. 256-259, 265-268 and part of p. 198 are in the autograph of the grammarian Dr John David Rhys (1534-1609); his peculiar orthography begins on p. 13, l. 21. The poetical extracts vary in length from three to fifty lines. The lines selected are not always consecutive; they are even occasionally fragmentary, and many words are explained or glossed. The awdl on p. 256 is in a different but contemporary hand from that of Dr John David Rhys. For p. 265, cf. the text on pp. 22-24, which agrees in part. For the dating of this manuscript see p. 207.
The text printed in Dr John David Rhys's Grammar (London, 1592), pp. 297-298, 301-302, 303 (cols. ii and iii), pp. 300-301, p. 303, col. iv, p. 303, 'Nota', and p. 304 is taken from, respectively, pp. 199-206, 207, 207b, 213, 214, and 224 of this manuscript.

Miscellaneous papers, home-made booklets, etc., containing material in the hand of Edward Williams ('Iolo Morganwg') bound together in one volume. P. xliii bears the inscription 'Trioedd amrafaelion a gynnulliwyd yng Ngwynedd yn y Flwyddyn 1799', and underneath this is a list of the names of six series of Welsh triads and a note (probably in the hand of Taliesin Williams, son of Edward Williams) which reads 'This Packet contains a variety of Triads resembl[ing] very much those of the Island of Britain and that are in all probability some of the lost ones of that Class. Jan. 17, 1831'. P. 1 bears the inscription 'Trioedd amrafaelion a gasglwyd yng Ngwynedd yn y flwyddyn 1799 Gan Iolo Morganwg', and underneath this is a list of the names of seven series of triads. Following on pp. 3-70 are series of triads with the superscriptions 'Trioedd Cerdd o Ddosparth Cerdd Dafawd Simwnt Fychan Bencerdd, A Robert Fychan o Hengwrt a'i dadysgrifennodd o Lyfr yn Llaw S.F. ei hun' (according to a note added to this superscription and a further note on p. 16 this series was copied in 1799 by Edward Williams from Panton MS 35 [now NLW MS 2003] in the hand of the Reverend Evan Evans ('Ieuan Brydydd Hir')), 'Trioedd o Lyfr y Parchedig Mr. Davies o Fangor' (with added note 'Yn Llyfr Twm o'r Nant y mae'r Trioedd hyn a'r rhai a'u canlynant dan enw Trioedd Llogell Rhison'), 'Trioedd Taliesin o'r un Llyfr' (with added note 'Trioedd Llogell Rhison yn Llyfr Twm o'r Nant'), '[Trioedd] Eraill o amryw lyfrau' (with added note 'Twm o'r Nant, D. Ddu, &c .'), 'Trioedd Ynys Prydain o Lyfr D[afydd] Ddu Eryri', and 'Llyma Drioedd Llogell Rhison o Lyfr Mr. Davies o Benegos' (with added note 'y mae y rhain yn Nosparth y Ford Gron cynn amser Llogell Rhison'). P. 81 contains a list of the contents of pp. 87-121, and is followed by pp. 83-4, a series of miscellaneous triads, p. 85, a note headed 'Mesurau Cerdd dafawd', pp. 87-112, a series of triads entitled 'Trioedd Ynys Prydain', and pp. 112-21, a list of 'Dewis bethau Taliesin', three triads, eight stanzas of Welsh verse entitled 'Cân y Magwraeth' and attributed to Gwion bach, further miscellaneous triads, and a series of triads with the superscription 'Trioedd o Lyfr Mr. Panton'. Pp. 133-202 contain a series of one hundred and twenty-six triads with the superscription 'Llyma Drioedd Ynys Prydain sef ydynt Trioedd Cof a chadw a gwybodaeth am hynodion o Ddynion ac o bethau a fuant yn Ynys Prydain ac ar ddamwain a damcwydd i Genedl y Cymry' reputedly compiled by Thomas Jones of Tregaron ['Twm Siôn Cati'] in 1601 from the works of Caradawc Nant Garfan and Ieuan Brechfa and copied [by Edward Williams] from a volume belonging to the Reverend Mr. Richards of Llanegwad [co. Carmarthen] then on loan to Rys Thomas, printer, and the Reverend Mr. Walters of Pont Faen, Glamorgan (see the notes at the beginning and end of the series on p. 133 and p. 202). This is the series of triads generally known as 'The Third Series of Trioedd Ynys Prydain' the text of which was published in The Myvyrian Archaiology of Wales . . ., vol. II, 1801, pp. 57-75. (continued)

Other items in the volume include a note on the development of 'These Triades' [i.e. the Trioedd Ynys Prydain] (125), an incomplete list headed 'Pedwar Cerddawr Graddawl' (126), a note on the composition of a barony or manor (131), a list of the twenty-four knights of King Arthur's court ('Llyma enwau y pedwar marchog ar hugain a fuant gynteifion y Ford Gron gydag Arthur ymherawdr Ynys Prydain yng Nghaerllion ar wysg (o Lyfr Twm o'r Nant, 1799)') (209-14), further triads including 'Trioedd Barddas' and 'Trioedd yr Ellyllion A wnelynt Ryfeddodau a gwyrthiau . . .' (217-18, 221-2, 229-38, 241-3, 246-7, 258-65, 272, 283-5), lists Of 'y saith gelfyddyd wladaidd' and 'y saith gelfyddyd ddinesig' (219), an English translation of triads 1 and 2 of 'Trioedd Ynys Prydain' (222-3), a further list of King Arthur's knights ('Pedwar marchog ar hugain oedd [yn] llys Arthur ac arnynt gyneddfau naturiol o orchest bob un mwy nog ar arall . . .') (225-7), an anecdote relating how Papists set fire to the house and outbuildings of Dr. William Morgan, incumbent of Llanraiadr ym Mochnant, in an attempt to prevent him proceeding with his task of translating the Bible into Welsh extracted allegedly 'o Lyfr Dyddgof y Parchedig Evan Evans y Prydydd Hir . . .' (254), a sketch plan relating to a furnace and forge (270-71), a short Welsh - English word list (278), a list of 'Dewis bethau Gwion Bach' (283), notes relating to the development of Welsh strict-metre systems or schemes (291), notes relating to the so-called 'Moelmutian' triads and laws (293-300, and ? 309-12), and transcripts of, or extracts from, miscellaneous Welsh strict- and free-metre poems including stanzas, etc., attributed to Gryfydd Gruc, Rhys Tyganwy, D[afydd] ap Edmund, Gwawdrydd, Sir Thomas Jones (circa 1600), D[afydd] ab Gwilym, and Gwion Bach (219-20, 227-8, 253, 257, 279-82). In one instance notes have been written on the dorse of a printed leaflet containing proposals for publishing 'A Welsh Paraphrase on St. Matthew's Gospel or a Translation of Dr. Clarke's Paraphrase . . .' by the Rev. Richard Jones, curate of Ruthin, in 1799, and in another on the dorse of a printed leaflet announcing the printing of Edward Williams's two volumes of English verse Poems Lyric and Pastoral.

Miscellaneous papers containing lists, notes, etc., in the hand of Edward Williams ('Iolo Morganwg') bound together in one volume. The contents consist largely of groups or lists of Welsh words. Included are lists with the superscriptions 'Geiriadur William Cynwal o Lyfr William Morys' with an added note 'medd Llyfr Dr. Williams o Gaernarfon o ba un y cymmerais i ef. I[orwer]th G[wily]m' (an incomplete alphabetical list A-D only; pp. 7- 38); 'Extracts from an old vocabulary' (pp. 111-13); 'Coincidences of Silurian and Cornish' (an incomplete alphabetical list A-G only; pp. 145- 60); 'Welsh Words from the Welsh Orbis Pictus (Merthyr)' (pp. 163-4); 'Cannons of Etymology' (pp. 171-3); 'North Walicisms' (p. 210); 'Welsh words collected in N[orth] W[ales]' (pp. 219-?20); 'Terms in sacred poetry, &c.' (p. 343); and '[Words from the] Gododin' (p. 375); and lists or groups without superscriptions. The Welsh words are often followed by English definitions or equivalents and the lists which appear on pp. 95- 110, 115-17, 127-8, 131-42, and 145-60 also give Breton or Cornish cognates. Pp. 255-69 contain an incomplete list of words (A-I only) with the superscription 'Welsh words from the Cotton MS.'. The words in this instance, however, are not Welsh but Cornish and correspond to those to be found in the old Cornish vocabulary which appears in [British Museum] Cottonian MS [Vespasian A. xiv] (see Henry Lewis: Llawlyfr Cernyweg Canol (Caerdydd, 1946), tt. 2-3. Internal evidence suggests that the present list may have been copied from that published in William Pryce: Archaeologia Cornu-Britannica . . . (Sherborne, 1790)). Also included in the volume are notes headed 'Deuddeg prif ragorgamp Cerdd dafod' (p. 170), a note on 'The Yniales Vocabulary . . . original (sic) compiled in this form by Hopkin ap Thomas . . .' (p. 174), a list of Glamorgan idioms (pp. 175-6), extracts from John Jones: The Tower of Babel or Essays on the confusion of tongues ( pp. 199-200), four stanzas of Welsh verse attributed to Watkin Powel 'o Ben y Fai' (p. 293), a list headed 'Barbarisms of Wm. Owain in D. G.' [? Barddoniaeth Dafydd ab Gwilym, 1789] (pp. 325-6), a list of 'Names of God in various Languages' (pp. 345-7), a list of seven 'Peculiarites (sic) of the North Walian Dialect' (p. 387), various grammatical and etymological notes relating to the Welsh language, and other miscellanea. Notes in one instance have been written on the dorse of a ? holograph letter, June 1817, from William Vaughan from Lanelay to Mr. Jones, overseer of the poor of Tythegston, giving an opinion concerning a pauper's settlement and his contract with his master, and in two other instances on the dorse or margins of copies of a printed leaflet announcing the printing of Edward Williams's two volumes of English verse Poems Lyric and Pastoral.