The Unknown Quantity
- Ano: 1919
- País: United States of America
- Xénero: Drama
- Estudo: Vitagraph Company of America
- Palabra clave: lost film
- Director: Thomas R. Mills
- Reparto: Corinne Griffith, Huntley Gordon, Harry Davenport, Jack McLean, Jack Ridgeway, F.R. Buckley
