“…Papers by Bastian (1949 on), Cannon (1955), Gridgeman (1955), Hiskey et al (1949 on), Kortum (1937), Lothian (1956), Neal (1956, Reilley et al (1955 on), Ringbom et al(1939Ringbom et al( , 1953, all give useful practical and theoretical details and (many of them) bibliographies. There is, for instance, much to be said for and against reading in % T instead of absorbance, calibrating the responses and reading-off from the calibration curves instead of directly reading absorbance-differences.…”