FRENCH COLONIES DOUBLE SOL (also
known as 24 Deniers or Sou Marqué)
Under the Edict of October 1738, all of the earlier French coins of 30
Deniers were recalled and replaced with a new billon coin with a value of
24 Deniers. These "Double Sols" or "Sous Marqués"
were issued from 1738 to 1864. In the earliest years, all of the
French mints produced Double Sols; in later years, only the Paris and
Strasbourg facilities were used.
Although billon is already
an alloy with a low percentage of silver, many of the later issues were
debased even further. In extreme cases, the only silver in the coins
was a thin plating applied over the surfaces. Thus, it is not
uncommon to find circulated examples with a copper color.
Conversely, examples with a high percentage of the original silvering
still remaining are sometimes quite rare or non-existent.
"An Illustrated Catalogue Of The French Billon Coinage In The
Americas" by Robert A. Vlack