HE was the controversial American dentist who pioneered the use of laughing gas as an anaesthetic, went mad and died in prison ...

but now, more than a century and a half after his tragic death, fellow medics are trying to work out whether Horace Wells was the real life inspiration behind Dr Jekyll and Mr Hyde.

Extensive research is now underway to try to pinpoint if Wells - who was recognised after his death as one of the founding fathers of anaesthetics - was immortalised in Scottish author Robert Louis Stevenson's masterpiece the Strange Case of Dr Jekyll and Mr Hyde.

The intriguing idea that Wells could have provided the inspiration for the famous story, which explores the duality of human existence, has been discussed in a paper published in the Journal of Anesthesia (corr) History. It notes this link is often referred to in historical information about Wells' gravesite in Cedar Hill Cemetery, Connecticut, as well as being mused upon by authors and academics in the US.

The authors of the paper say they want to establish if there was a literacy legacy marking the life of Wells, who suffered a dramatic descent from respectable dentist into drugs, violence, madness and ruin.

The highlight of Wells' career was discovering that nitrous oxide - also known as laughing gas - was effective in relieving pain. But in 1845 a demonstration to prove this while performing a tooth extraction on a medical student ended in accusations it was a hoax after the patient cried out - even though the student later admitted he had felt no pain.

The incident was a huge blow to Wells' career, which quickly spiralled downwards. He began abusing ether and chloroform and in 1848, while under the influence of drugs, he was arrested after splashing acid on two prostitutes. Wells then committed suicide while in New York's infamous Tombs Prison by slashing an artery in his groin - after inhaling chloroform for pain relief.

The fall from grace of the respected dentist and his turning to drugs could be interpreted as his "own version of Mr Hyde", the paper says. It also notes that Wells, like Hyde, only found absolution of their "evil selves" in death.

However after scrutinising evidence such as original documents from Stevenson and contemporary newspaper reports from the author's time, the medics have concluded there is insufficient evidence to establish any definite relationship between Wells and Stevenson.

The paper notes that Stevenson did have the experience of having his teeth removed in San Francisco while under anaesthesia, but added: "Other scant evidence forms rather tenuous, indirect speculations that Wells held influence over Stevenson, based on the convenient compatibility with the latter's ideologies and the former's life history.

"Without the essential validity of verified evidence, any analysis inevitably cannot prove a link."

The paper also notes: "As the dentist died two years before the author's birth, it is unlikely that Stevenson came across any newspaper or scientific article in Britain."

The study was carried out by Dr Sukumar Desai, associate professor of anaesthesia at Brigham & Women's Hospital, Boston, USA and Rini Vyas, a fourth-year medical student at the University of Leeds.

Vyas said the project had taken several months to complete and had included examination of original documents from Robert Louis Stevenson and the Stevenson family, held in the special collections at Leeds University, as well as the university's archives of contemporary newspapers from Stevenson's time.

She said: "Horace Wells was the controversial founding father of anaesthesia, meaning that his legacy has been subject to considerable speculation at various points in history.

"By exploring claims that Stevenson's story of Jekyll and Hyde was inspired by Wells, we hoped to find the truth about whether part of Wells' legacy is truly embedded in literary form."

But the authors concluded: "All claims to any relationship between Wells and the novel come from the US and none of them are backed by evidence.

"In the absence of evidence supporting a relationship between the behaviour exhibited by Wells during his final days and any inspiration that Stevenson might have derived from it, we conclude that there is insufficient evidence to suggest any relationship between them."

The contribution of Wells to the discovery of anaesthesia was recognised after his death by the medical community and his son commissioned a sculpture as a memorial to him at Cedar Hill Cemetery.

Professor Richard Drury, of the Robert Louis Stevenson website, said he believed it was unlikely there was any link between Wells and Stevenson's literary creation.

"There's no evidence that Stevenson knew about the case: there were other double-life and double-personality cases that he knew of as well as a whole literary tradition of doubles," he added.