Measurements of the spatial gain associated with stimulated Brillouin and Rayleigh-wing scattering are presented. These results are obtained by amplifying a signal in a short cell. This technique enables us to obtain reliable data even in liquids where self-focusing has a very low threshold. Comparison of measured and calculated gains in different liquids demonstrates the steady-state character of the gain at the Brillouin frequency for larger-linewidth liquids and the transient effect in liquids with sharper linewidths. We give values for the gain at the Stokes frequencies on the Rayleigh wings of nitrobenzene and toluene, and compare them with the calculated values using simple models for the scattering cross section.