Who is Henry Pleyel from Wieland; and Memoirs of Carwin the Biloquist and what is their importance?

Henry Pleyel is one of Clara and Theodore Wieland's childhood friends. He is Catharine's brother. He is in love with Clara, but he is easily fooled into thinking that Clara has soiled her character through her interactions with Carwin. As a result, he severs all ties with her. Despite her protestations of innocence, Henry believes what he's been told, until he is later offered a genuine explanation. Afterward, he and Clara reconcile and marry soon after the death of his first wife.