Which concept is at the center of the eighteenth-century explanation of combustion?

Which concept is at the center of the eighteenth-century explanation of combustion?

• A. Oxygen
• B. Nitrogen
• C. Phlogiston
• D. Hydrogen

Answer: (C)

In the eighteenth century, burning was explained by a substance called phlogiston. Flammable materials were thought to contain phlogiston, which was released when they burned, leaving a residue called calx. Air played a role as the medium that interacts with the burning material, but the important idea was that a hidden substance—phlogiston—exits the material during combustion. This view persisted until experiments showed that burning actually involves oxygen from the air combining with the fuel, leading to the modern understanding. So the central concept of that era was the idea of phlogiston.

In the eighteenth century, burning was explained by a substance called phlogiston. Flammable materials were thought to contain phlogiston, which was released when they burned, leaving a residue called calx. Air played a role as the medium that interacts with the burning material, but the important idea was that a hidden substance—phlogiston—exits the material during combustion. This view persisted until experiments showed that burning actually involves oxygen from the air combining with the fuel, leading to the modern understanding. So the central concept of that era was the idea of phlogiston.