The quality of ancient silver coinage is often seen as a comment on the fiscal health of the issuing states. This is nowhere more apparent than with Roman coinages, which witnessed heavy debasements during the first three centuries of our era. Two processes are detectable: a reduction in the fineness of the alloys; and a reduction in weight standards. However, the hypothesis here is that the two processes are interlinked, and that the second is largely an illusion caused by the first.One of the most reliable techniques for doing this is to sample by drilling into the cylindrical edge of the coin, discarding the first millimetre or so of turnings and retaining the sample from deeper within. However, for small, or thin coins, such an approach is not possible. Negative muons offer the possibility of a non-destructive multi-elemental analysis