Calcium carbide (CaC₂)is manufactured by passing an electric arc through a mixture of lime (CaO) and coal tar.

Calcium carbide reacts with water to produce acetylene. When burned in air, acetylene produces a luminous flame, hence early interest in the process.

Acetylene is colorless, extremely flammable gas with a detectable garlic like odor. In its free state, acetylene may violently decompose if the pressure of the gas exceeds 15 psig. Acetylene is shipped and stored dissolved in acetone. In the united States, about 80% of acetylene use is in chemical synthesis while 20% is used for welding.

Mixtures of oxygen and aectylene burn at high temperatures (6000 °F) and can be used for welding many metals (pdf document).