High-resolution measurements of widths and shifts of vibrational-rotational lines in infrared spectra of gaseous methane have been made in the laboratory. This research introduced at ambient temperatures the rare gases helium, neon, argon, krypton, and xenon and the diatomics hydrogen, nitrogen, oxygen, and carbon monoxide at pressures from 100 to 700 torr. Detailed quantitative studies of correlations with masses, polarizabilities and quadrupole moments suggest that there may be some functional dependences on these physical parameters. ¿ American Geophysical Union 1991