[en] Using our curve-of-growth measurements in the reduction of planetary observations, we find methane abundances in the atmospheres of Jupiter and Saturn to be between a factor of 3 and 4 larger than previously accepted values based on the analysis of the 3ν₃ band at 1.1 μ, while the amount on Titan is significantly less than that obtained from an analysis of 3ν₃ with the assumption of a pure methane atmosphere. The present results, when combined with the 3ν₃ analysis, suggest a surface pressure on Titan of at least 0.4 atm. Extrapolation of these laboratory data to the observations of Uranus and Neptune lead to single air mass column densities of 5.8 and 7.6 km-am of methane, respectively