This procedure relies on a set of experimentally determined matrix-independent relative calibration constants. The absolute calibration is made redundant by assuming that the sum of all weight fractions equals unity. The applicability of the quantitative method to the analysis of alloys is discussed with special reference to coins. Experimental results obtained from the analysis of an NBS-certified alloy and an ancient silver coin illustrated the accuracy and precision of the method. See also 20-32. -- AATA