Transcription on back of the photograph: "Dr. Gordan Duncan, professor of chemistry, works with freshmen students in a laboratory course which employs certain functions of the chromatograph. Here, Dr. Duncan's class hears his description of how to use the equipment for the determination of the radioactive half-life of Bismuth-210. The chromatograph is used for research and teaching projects primarily for the quantitative and qualitative determination of radioactive elements and compounds."