"The king of tonics and digestives."
"Alpine appetite cordial"
"Price: 3 francs, in all the pharmacies"
My guess is an old timey cure for heartburn/acid reflux, made from some plant that grows in the alpine.
Actually Wikipedia says that apertifs and digestifs are just alcohol that's served before or after a meal. Don't see why it would be sold at a pharmacy if that's the case, though.