ROYAL SOCIETY PAPERS. Letters relating to the transactions of the Royal Society addressed chiefly to Thomas Birch and other secretaries, or to successive Presidents, or to the Society itself as a body. Some refer to papers and communications included in Add. MSS. 4432-4441. The names of the writers are to be found in the Index of the present Catalogue. Two volumes (not arranged in strict order of date); 1663-1765.