"Rappaccini's Daughter", by Nathaniel Hawthorne, represents one of the earliest science fiction stories. Adapting an explorer's tale from India, it gave birth to a number of "Poisoned Garden" stories, where literary naturalists would use the poisoned garden as a vehicle to investigate the scientific progress of the age. Fans of weird fiction and science fiction will also see the influence of "Rappaccini's Daughter" in C. L. Moore's Northwest Smith stories. As foundational to science fiction as Frankenstein and The Castle of Otranto are, Hawthorne's novelette is a key to understanding not only weird fiction, but the American tradition of the short story.
The complete text can be found here, hosted by Columbia University.