The Absorption and Fluorescence Spectra of P-Terphenyl in Toluene.

The fluorescence spectrum of 1/2% p-terphenyl in toluene was obtained by means of a Hilger medium quartz spectrograph. The solution was contained in a 1 cm. thick quartz absorption cell taped over the spectrograph slit, and fluorescence was excited by a 40 mc. radium source placed next to the cell. The plate was exposed 65 hours and the density measured by a Leeds and Northrup recording microdensitometer.