The Unknown Quantity (film)

The Unknown Quantity is a lost 1919 American silent directed by Thomas R. Mills produced and distributed by the Vitagraph Company of America. It is based on the 1910 short story of the same name by O. Henry.

Plot
A profiteer's son falls in love with one of his father's victims and secures the acquittal of her brother who was falsely accused of murder.

Cast

 * Corinne Griffith - Mary Boyne
 * Huntley Gordon - Dan Kinsolving
 * Harry Davenport - Septimus Kinsolving
 * Jack Ridgeway - Thomas Boyne
 * Frederick Buckley - Peter Kenwitz
 * Jack McLean - Sammy Boyne