Confederacy, 1862, 2¢ green, Vertical Pair. Four large margins, tied by "Richmond, Va./Jan 22, 1863" cds on large cover endorsed "C.S. Patent Office, Official Business" to Charles H. Winston Esq, Richmond, docketed "Relating to SO3", Extremely Fine, A Great Rarity on this Double Drop Rate Cover.; signed Dietz. Scott No. 3  Estimate $2,000 - 3,000. Charles H. Winston, president of the Richmond Female Institute and later professor at the University of Richmond, was awarded C.S. Patent No. 145 for his "method of constructing [a] sukfuric acid chamber". Sulfuric acid (SO3) was one of the critical chemicals made in the South during the Civil War. It was necessary for the manufacture of mercury fulminate which was used in the production of percussion caps. Sulfuric acid was also used in the Daniell cell to produce electricity, particularly for the telegraph. Winston was instrumental in the establishment of a plant to manufacture sulfuric acid in Charlotte, North Carolina. $0 (Image)