10 centimes Essai en cupro-aluminium de 'UN DECIME'

The "UN DECIME" legend on this essai reflects an internal debate at the Monnaie de Paris over denominational nomenclature — whether to retain the older French term *décime* or standardize to *centimes* across the coinage system. The trial ultimately went nowhere; the centimes designation held, and no production coinage emerged from this particular experiment in either alloy or wording.

Copper-aluminium alloys were being tested seriously across several European mints in the early twentieth century as a cheaper, lighter alternative to bronze. France never adopted the composition for circulation.