The day and month are established by the relationship between this letter and the letter to George Darwin, 3 May [1879]); the year is established by references to the research for Erasmus Darwin, which was published in 1879.

The London Library is a membership library, established in 1841. George was looking for a biographical article about Erasmus Darwin (1731–1802) that was published in the Monthly Magazine, or, British Register, 1 June 1802 (Anon. 1802); a reference does appear in the index to the volume (Monthly Magazine 13 (1802): 716). The enclosure sent has not been identified, but may have been copied from the Monthly Review, which George had looked at instead of the Monthly Magazine (see letter from G. H. Darwin, 5 May 1879); there are brief references to Erasmus Darwin in Monthly Review 37 (1802): 132 and 38 (1802): 156 and 163.

CD may have asked George to find the published version of Erasmus Darwin’s first poem on the death of Frederick Lewis, prince of Wales, written in 1751; it was not published until 1795 (Erasmus Darwin, p. 12).