Over one hundred and thirty letters, [?1831]-[c. 1860], from Henry Petty-Fitzmaurice, third marquis of Lansdowne, to Nassau William Senior, mainly discussing parliamentary business and contemporary political issues, including Ireland and poor law administration, often with reference to Senior's own writings.

Memoranda by Nassau Senior on a conference on the Irish church and education, [c. 1835], on the redundancy of population in Ireland, 1837 (two versions) and on Poor Law administration in Ireland, [c. 1837]. The memoranda are accompanied by covering letters from Senior to Lord Howick, 1837, and to Lord Lansdowne, 1835-1837.