[A handwritten inscription leading to new information].

Manuscripts written on white pages or margins of ancient books often present some interest for the historian. Here is studied the handwritten inscription on the page facing the frontispiece of the Pharmacopée des dogmatiques by Joseph du Chesne. It referred to the opinion of traditional doctors such as Guy Patin or Jean Riolan about Joseph du Chesne and chemical medicine issued from the theories of Paracelsus. A special interest was given to the pills against plague.