The file comprises letters, 1829-1851, relating mainly to the cause at Pantydefaid chapel, parish of Llandysul and John Jones's relationship with the congregation; John Jones's school at Cribyn and the Unitarian cause in the Neath area.

The file comprises letters, 1829-1862, relating mainly to the Rev. John Jones's relationship with the congregation at Pantydefaid chapel, parish of Llandysul; the opening of a school by John Jones; Yr Ymofynydd; and Unitarian matters and doctrines. One letter to the Rev. O. Evans, Cefn, is also included.

The file comprises letters, 1833-1849, relating mainly to Unitarian matters, and in particular the cause at Pantydefaid chapel, parish of Llandysul. The letter of 1833 (FJ1/3/1) is addressed to Rees Jones [John Jones's brother], Ffynonoer.

The series consists of notes, [c. 1877]-1919, relating to the history of the Old Meeting House (Hen Dŷ Cwrdd), Aberdare; together with reports, 1908, from Unitarian churches relating to attendances; press cuttings, 1877, concerning the Llwynrhydowen eviction in 1876 and notes on ministers of Merthyr Tydfil and Cefncoedycymer.

The series comprises a statement by the Rev. John Jones, March 1833, 'of the origin and progress of the misunderstanding existing between the members of the once united and friendly congregation at Pantydefaid in the parish of Llandysul, Cardiganshire'. Also included is a transcript, in Rev. Simon Jones's hand, of one page of the statement.