The Regenerates (1917)

Mynderse Van Dyun, a wealthy old New York aristocrat, has one goal in life, to see his granddaughter Catherine and grandson Pell married; for, although they are cousins, the marriage would perpetuate the family name. Catherine, however, is in love with Paul La Farge and detests her drug-addicted cousin, who seduces and then secretly marries her maid, Nora Duffy.