Edward Bellamy 
Dr. Heidenhoff’s Process 

The novel concerns a doctor who develops a mechanical method of eradicating painful memories from people’s brains so that they can feel good about life again. The protagonist persuades his lover to try the process after she has been seduced by a rival. She is transformed until the protagonist awakes and realises that he has dreamt of the doctor and his process and that his lover has committed suicide. (Wikipedia)