The Unknown Quantity
- Annu: 1919
- Paese: United States of America
- Genre: Drama
- Studio: Vitagraph Company of America
- Parolla chjave: lost film
- Direttore: Thomas R. Mills
- Cast: Corinne Griffith, Huntley Gordon, Harry Davenport, Jack McLean, Jack Ridgeway, F.R. Buckley
