  The results of experimental testing the existence of intense Lorentzian--like
wings with FWHM $\sim 4.5 cm^{-1}$ in the absorption spectra of polyatomic
molecules in a gas phase are presented. Two independent experimental methods
were used for evaluating the integral intensity of the line wings for a number
of substances. In the first case, the cross--section of the far wings of
absorption bands in a gas phase spectrum were measured. Then, these band wings
were extrapolated inside the contour of absorption band. In the second case,
the saturation degree of the linear spectrum of molecules was determined.
Radiation of a pulsed $CO_2$--laser was used at low gas pressure ($\sim 16$
mtorr) and averaged excitation level of molecules ${<n>}\sim 0.1$
quanta/molecule. The values obtained by these two independent methods coincide
for a variety of molecules. The average relative integral intensity of the line
wings varied from $\sim 0.6%$ for $SF_6$ and $SiF_4$ to $\sim 90%$ for
$(CF_3)_2O$ and $(CF_3)_2CO$.
