London, UK: J. Johnson, 1772. First Edition. Hardcover. 4to ( 21 x 17 cm). 422, 812 pp. Recent brown cloth covers with gilt titles to dark brown cloth spines. Signature of PO (1872) to title page of volume II, rest of text blocks tight and unmarked. Folding chart opposite title..... More about The History and Present State of Discoveries relating to Vision, Light And Colours.(2 Vols