The feasibility of converting North Sea gas into useful products has been explored by quenching various mixtures of CH 4 with O 2 , N 2 and Ar after passage through discharges designed to achieve uniform mixing. The first of these devices, a drilled watchmakers’ jewel through which both the gas flow and the discharge were constrained to pass, produced much C 2 H 2 but proved subject to clogging by solid carbon and was replaced by a plasma jet spun at high rates by a magnetic field. Quenching the hot gases in small, water-cooled nozzles, followed by gas chromatographic analysis, revealed large yields - up to 80% of the available C - of C 2 H 2 from CH 4 /Ar mixtures. Carbon black and HCN (in N 2 -rich mixtures) were also produced in appreciable quantities. In exploring the usefulness of arc-augmented flames for such purposes, the practical limitations and the effects of oxygen admixture were established. Oxygen diminishes the yield of endothermic products but also the arc power requirement, by contributing to the total gas enthalpy. Based on the production of acetylene, small admixtures of air appear advantageous.