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The variation of the luminescence yield of an active molecule introduced into an organic medium in various states of aggregation makes it possible to determine the structural changes in the solvent medium. The possibilities of the luminescence method are even further increased if the phosphorescence which develops in particular states of the medium is investigated in conjunction with the fluorescence. The dependence of the luminescence intensity on the temperature of the polymer into which the molecule was introduced is an extremely sensitive indication of the mobility of the environment [1]. The present work illustrates the relation between the luminescence intensity of a compound introduced as an activator and the physical state of the solvent medium.EXPE RIME NTAL Alcohols which had been additionaUy purified by distillation were used for the investigations. Their purity was controlled by their refractive indices and their luminescence. The compounds introduced as activators were purified by fractional zone melting (35-60 passes). The investigated solutions were placed in a metallic cryostat with three quartz windows by means of which it was possible to record the luminescence from the specimen and simultaneously to observe changes in the specimen.To investigate the temperature dependence of the intensity the specimen was cooled to 77°K in the eryostat and held at this temperature for 15-20 min. It could then be heated without external influences,

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