Sabine’s Royal Society address [awarding the Copley Medal to CD], in referring to the Origin, did not contain the words "expressly excluded". The actual words were "expressly omitted from the grounds of our award". This was not meant to place the Origin on a sort of index expurgatorium, but was a simple statement of fact.

Wishes to correct an expression in his last letter which is "perhaps not rigorously exact": he should not have said "declining to honour it [the Origin] with the Copley Medal" but simply "not honouring it with the Copley medal". "Declining implies having been asked and there was no asking in the present case."