Adelaide Blanche de la Tremoille was born in France in 1855. Details about her early life are sparse, but she married Thomas Edwin Bartlett, a wealthy grocer, in 1875. Their marriage was reportedly unconventional; some accounts suggest it was intended to be platonic. Despite this, Adelaide became pregnant in 1881 but suffered a stillbirth. In early 1885, the couple became acquainted with the Reverend George Dyson, a Wesleyan minister who served as Adelaide's tutor and the couple's spiritual advisor. Dyson grew close to both Adelaide and Thomas, even being named executor of Thomas's will.​

On December 31, 1885, after returning from a dental visit, Thomas Edwin Bartlett retired to bed in their Pimlico residence. In the early hours of January 1, 1886, Adelaide found him unresponsive and summoned Dr. Alfred Leach, who pronounced him dead. A post-mortem examination revealed a fatal quantity of chloroform in Thomas's stomach, with no signs of damage to his throat or windpipe, leading to questions about how the substance was ingested.​

Adelaide was arrested on February 11, 1886, and charged with her husband's murder. The trial commenced on April 12, 1886, at the Old Bailey, attracting significant media attention. Sir Edward Clarke represented Adelaide, suggesting that Thomas may have committed suicide. The prosecution, led by Attorney General Sir Charles Russell, struggled to prove how Adelaide could have administered the chloroform without causing internal injuries. The jury concluded that, although there was "grave suspicion" against Adelaide, there was insufficient evidence to demonstrate how or by whom the chloroform was administered, resulting in her acquittal.​

Following the trial, both Adelaide and Dyson disappeared from public view. Speculations about Adelaide's later life include theories that she emigrated to the United States and settled in Connecticut, though her exact fate remains unknown. Dyson's subsequent life is also shrouded in mystery, with various accounts suggesting he moved to America or Australia and assumed different identities.​