There was no message in it, just an old bottle found buried in our garden. How old is it? I have no idea - not too old - the stopper is made of rubber (natural, I think) but the bottle is made of thick, swirly glass and the letters are raised. It says EAU DES CARMES BOYER. I looked it up on the internet, and they are still selling the stuff in parmacies here in France. It's some sort of distilled plant and spice alcohol. You put a few drops on a sugar cube to take it, or dilute it in a glass of water. It's a digestive, it helps you if you've had a shock, it can give you a burst of energy (I think that's the sugar cube but then again, I'm naturally skeptical...)
I'm also curious and so I wrote a note to the manufactuerer and asked if they could date the bottle for me. They wrote back asking for a photo and I sent this one. Now I'm waiting to see how old the bottle in the garden is.