Sadly, I'm not well versed in stamps from France, as I only have a select few, and I don't even have a current worldwide catalog from which to refer. Nevertheless, using an old catalog on hand I think this may be a Scott 95 (?) although I'm not sure if the color is accurate or not. Maybe it's just due to the fact that the stamp is well over a century old.

Can anyone confirm the ID of the stamp for me? In any event, it sure has a nice SON cancel from 1900.