Since context is highly important for these kinds of question, could you provide an example, like a transcript of one of the places where this saluting occurs?

I also remember wondering about this when I read the book. To add context there was a scene before a dual that the Count meets the Viscount de Morcerf on the dueling field. The Viscount salutes in a form of greeting. I assumed it was a specific form of greeting between French nobleman at the time but I would love to know what the actual greeting was.