When Joseph Priestley (1733-1804) is remembered today, it’s usually for his 1774 discovery, in England, of oxygen. Few know he was a noted theologian, political progressive, and prolific author whose scientific contributions include the development of the modern timeline, the carbonation process, the identification of carbon monoxide and other gases, early experiments in electricity and an early understanding of the inter-relationship of plants and animals mediated by gases: oxygen and carbon dioxide and the role of sunlight in photosynthesis.