The bulk of the collection consists of correspondence: the Singers were clearly vigorous letter writers and both Charles and Dorothea had an enormous number of family, friends and acquaintances. Unfortunately many of their letters were hand written and very few carbon copies survive. Very occasionally an attempt at methodical selection and arrangement is evident: on the whole correspondence had been kept in alphabetical order, and this has been retained in the arrangement of the collection. Dorothea and Charles' correspondence was fairly mixed (reflecting their working life together) with the exception of two distinct groups: correspondence about Dorothea's research on alchemical manuscripts, and later correspondence about her hearing aids.
The main part of the collection centres on the correspondence; this has been grouped together in a self-evident sequence: writings and biographical personal papers follow. Certain of Dorothea's papers remained clearly distinct and these have been kept together. Section E contains a variety of material relating to Jewish refugees, which had been placed on one side by Dorothea after the war for permanent preservation. It has not been listed in detail but sorted into three broad categories. The last section, comprising additional correspondence of the Singers with Sir Zachary Cope, Sir Arthur Salusbury MacNalty and Dr F N L Poynter, is not strictly part of the collection, but these groups of correspondence were given to the Institute to be placed alongside the Singer papers.
