| RefNo | Title | Date |
| NLB/35/187 | Copy letter from Robert William Frederick Harrison, to Dr Seligmann [Charles Gabriel Seligman] | 29 April 1907 |
| NLB/35/669 | Copy letter from Robert William Frederick Harrison, to Mr Chatham Pexton, 48 Gray's Inn Road, W.C. | 28 June 1907 |
| MC/22/394 | Letter from [Charles Gabriel] Seligman, 15 York Terrace, Regent's Park, to [Robert William Frederick] Harrison | 29 May 1907 |
| MC/22/395 | Letter from [Charles Gabriel] Seligman, Hungerford, to [Robert William Fredrick] Harrison | 8 June 1907 |
| NLB/59/406 | Copy letter from Edwin Deller, Assistant Secretary of the Royal Society; to Professor [Charles Gabriel] Seligman, FRS | 30 September 1920 |
| NLB/60/78 | Copy letter from Edwin Deller, Assistant Secretary of the Royal Society; to Dr. [Charles Gabriel] Seligman, FRS | 8 December 1920 |
| NLB/57/838 | Copy letter from Sir William Bate Hardy, FRS, Secretary of the Royal Society; to Sir Walter [Morley] Fletcher, FRS, KBE | 20 February 1920 |
| NLB/69/40 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Dr. [Charles Gabriel] Seligman, FRS | 17 December 1925 |
| NLB/68/523 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Professor [Charles Gabriel] Seligman, FRS | 27 July 1925 |
| NLB/71/747 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Dr. [Charles Gabriel] Seligman, FRS | 22 October 1928 |
| EC/1919/10 | Seligman, Charles Gabriel: certificate of election to the Royal Society | |
| MC/22/397 | Letter from [Charles Gabriel] Seligman, 15 York Terrace, Regent's Park, to [Robert William Frederick] Harrison | 18 June 1907 |
| MC/22/396 | Letter from [Charles Gabriel] Seligman, Hungerford, to [Robert William Fredrick] Harrison, Assistant Secretary of the Royal Society | 16 June 1907 |
| MC/22/393 | Letter from [Charles Gabriel] Seligman, 15 York Terrace, Regent's Park, to the Assistant Secretary of the Royal Society | 25 May 1907 |