Observation of Excitons in a Molecular Liquid: Specular Reflection Spectrum of $\alpha -\mathrm{M}\mathrm{e}\mathrm{t}\mathrm{h}\mathrm{y}\mathrm{l}\mathrm{n}\mathrm{a}\mathrm{p}\mathrm{h}\mathrm{t}\mathrm{h}\mathrm{a}\mathrm{l}\mathrm{e}\mathrm{n}\mathrm{e}$

The normal-incidence specular-reflection spectrum of liquid $\alpha -\mathrm{m}\mathrm{e}\mathrm{t}\mathrm{h}\mathrm{y}\mathrm{l}\mathrm{n}\mathrm{a}\mathrm{p}\mathrm{h}\mathrm{t}\mathrm{h}\mathrm{a}\mathrm{l}\mathrm{e}\mathrm{n}\mathrm{e}$ was obtained for the wavelength region from 215 to 400 nm. Comparison of the Kramers-Kronig transform of the reflection spectrum with the absorption spectrum of $\alpha -\mathrm{m}\mathrm{e}\mathrm{t}\mathrm{h}\mathrm{y}\mathrm{l}\mathrm{n}\mathrm{a}\mathrm{p}\mathrm{h}\mathrm{t}\mathrm{h}\mathrm{a}\mathrm{l}\mathrm{e}\mathrm{n}\mathrm{e}$ is cyclohexane shows the bands of the neat-liquid spectrum shift to lower energy and display significant broadening. These effects support the existence of excitons in molecular liquids.