Copper coins belonging to the period from 40 years before to 200 years after Diocletian's money reform (A.D. 294) were analyzed for Ag, Au, and Sb. As the Ag concentration varies by 500:1 emphasis has been laid only on the determination of how the concentration changes, not on the abs. value of the percentages. The older coins have more Ag and Au than those minted later. The coins investigated can be ordered according to their Ag concentration in 3 groups: The 1st group consists of coins just before or during Diocletian's rule, the 2nd of the time of his successor Constantine I, and the 3rd of the time of Theodosius I (A.D. 395) and after. The Ag concentrations vary in the 3 groups as 36:10:1, whereas the Ag/Au ratio as 2.7:1.9:1. As Cu contents decrease together with Ag contents, it is concluded that Au was an impurity of Ag which was added for some unknown reason to Cu. Sb is not detected in the oldest coins, but it appears at Diocletian's time. As in most coins Sb contents do not vary much, even if the Ag contents vary by a factor of 40; it is concluded that Sb was not an impurity of Ag. An attempt is made to estimate the contents of the 3 metals. It is suggested to use the width at half-maximum intensity of a full energy peak of a gamma-ray spectrometer record for the determination of intensities of lines which are superimposed on an unknown background. This method is applied to the 0.41 Mev. Au line. From the shape of a line which is theresultant of 2 nonresolved lines, the contributions of the 2 components can be found. As an example, the composite line of 0.51 Mev. Cu and the 0.56 Mev. Sb is discussed. From <i>Nucl. Sci. Abstr., 19 (8), 1611 (1965). -- AATA