Joseph Priestly and Carbon Dioxide

In Leeds Joseph Priestley’s home was situated near a brewery. Whenever he walked by the brewery, Priestley observed an unusual phenomenon. He noticed that “fixed air” (carbon dioxide) was released in the process of fermentation and that this new “air” would extinguish burning pieces of wood and then drift to the ground. At home Priestley …

Phlogiston and Fire — The Isolation of Oxygen

In the mid-18th century, the most pressing issue in chemistry and physics was to determine what exactly happens when something burns. The prevailing theory was that flammable materials contained a substance called “phlogiston” (from the Greek word for burn) that was released during combustion.  The theory held that when a candle burned, for example, phlogiston …