Laboratory discharge experiments were performed with Wimshurst electrostatic generator with discharge energies between 0.005 and 0.1 J in air, in an atmosphere of various O2/Ar ratios, and an atmosphere of various O2/N2 ratios in order to determine relative NO, NO2, HNO3, and O3 production from a discharge. The results in air showed that the NO/NOx (NOx=NO+NO2) ratio varied between 0.75 and 0.95, depending on the discharge energies, that little O3 was produced except at very low discharge energies, and that no HNO3 was produced when the air was humidified. The results in an O2/Ar atmosphere showed that O3 production increased with descreasing O2 content of the atmosphere, that its production was kinetically controlled, and that its production probably takes place in the cooler regions of the discharge. In an atomosphere of various O2/N2 ratios the production of NOx was also seen to be kinetically controlled and was observed to reach a maximum when the O2 was 30--40%, although its production, unlike O3, probably takes place in the hot regions of the discharge and results from an ohmic heated channel. ¿ American Geophysical Union 1991