Which scientist first melted two pieces of ice by rubbing them together?

The scientist who first melted two pieces of ice by rubbing them together was Sir Humphry Davy. In 1799, Davy conducted an experiment where he rubbed two pieces of ice together in a vacuum, demonstrating that friction could generate enough heat to melt the ice; option [C]. This experiment provided significant evidence against the caloric theory, which proposed that heat was a fluid contained within substances. Instead, Davy’s experiment supported the idea that heat could be produced by mechanical action, thereby influencing the development of the kinetic theory of heat. Davy’s work helped pave the way for later discoveries in thermodynamics and the understanding of heat as a form of energy. Therefore, the correct option is [C] Davy. His contributions were crucial in shifting the scientific perspective on the nature of heat and energy.