A. J. Pleasonton

Augustus James Pleasonton (January 21, 1808 - July 26, 1894) was an American lawyer and soldier, active in Pennsylvania volunteer militia, particularly during the Buckshot War (1838) and Philadelphia Nativist Riots (1844), ultimately attaining the rank of brigadier general during the Civil War (1861-'65) and overseeing the home guard defence of Philadelphia. In his later years, Pleasonton championed a hypothesis that filtered blue light would promote vegetable and animal growth (as well as acting as a curative for various diseases in humans and animals), conducting experiments in greenhouses with blue glass, which he detailed in his monograph On the Influence of the Blue Color of the Sky in Developing Animal and Vegetable Life (1871) and follow-up book The Influence of the Blue Ray of the Sunlight and of the Blue Colour of the Sky (1876).