The ultraviolet spectra of high-molecular-weight materials were obtained by dispersing them in polyethylene, which had a negligible contribution to the spectrum between 2200 and 4000 A. The spectra of reference compounds as well as asphaltenes and polymers are given. The sample is stirred into melted polyethylene, and a portion of the dispersion is pressed between sheets of metal foil in a heated laboratory press to form a film. A circular plate cut from the film and mounted between two metal rings is inserted into the spectrophotometer to obtain a spectrum.