Surface light scattering has been used to study thermally excited capillary waves on solutions of a nonionic surfactant, n-decanoic acid in 0.005 M aqueous HCl. The capillary waves show no trace of the unexpected behavior previously found for ionic surfactants, suggesting that processes thought to act to reduce the stability of the dilatational surface waves in the ionic case are absent for the present system. The implications of this observation are discussed.