A Case of Poison (1915)

Mr. Barr is a young husband who is inclined to neglect his wife for the other woman. He refuses to accompany her shopping one afternoon and leaves, meeting another girl, whom he takes to the theater. Mrs. Barr is all broken up. She is visited by a friend who suggests that they go to a matinee. They do so and Mrs. Barr discovers Mr. Barr in a box with the other woman. She leaves very much broken up. She attempts suicide on a railroad track, but is frightened by the rumbling of the train. She next visits a drug store where her nervous manner gives away her intention to the druggist. Instead of giving her cyanide of potassium as she requests he gives her a bottle of plain water, marking it cyanide of potassium.

Drama