The American politician Charles Sumner, who visited Louis and observed him teaching at the Hôtel-Dieu de Paris, described him as "a tall man, with a countenance that seems quite passive."
Charles Sumner, der Louis am Hôtel-Dieu de Paris besuchte und bei seinem Unterricht beobachtete, beschreibt ihn als einen "großen Mann, with a countenance that seems quite passive."