| On The Principles of Political Economy, and Taxation
David Ricardo | |
| On the Processes for the Production of Ex Libris (Book-Plates)
John Vinycomb | |
| On the Prospects of Christianity / Bernard Shaw's Preface to Androcles and the Lion
Bernard Shaw | |
| On the quantum theory of radiation and the structure of the atom
Niels Bohr | |
| On the Reception of the 'Origin of Species'
Thomas Henry Huxley | |
| On the Red Chalk of England
Thomas Wiltshire | |
| On the red staircase
Mary Imlay Taylor | |
| On the Relations of Man to the Lower Animals
Thomas Henry Huxley | |
| On the relative motion of the earth and the luminiferous æther
Albert A. Michelson; Edward Williams Morley | |
| On the right of the British line
Gilbert Nobbs |
