The Grain of Dust (1918)

Stenographer Dorothy Hallowell works for a Wall Street law firm, and isn't aware that Frederick Norman, a junior partner in the firm, is madly in love with her, even though he is engaged to be married. To get closer to her, he finances her father's laboratory, but when Dorothy realizes what he's up to, she turns him down. His fiancee finds out and breaks their engagement. Dorothy moves back to her small town, but soon runs into trouble when stories of her "unseemly behavior" in New York result in her having to leave town and return to New York, where she manages to get into even more trouble. Complications ensue.