Fifty years ago, Eric Gow had a baffling and unexplained experience. As a 19-year-old sailor, he remembers going to a clandestine military establishment, where he was given something to drink in a sherry glass and experienced vivid hallucinations. Other servicemen also remember tripping: one thought he was seeing tigers jumping out of a wall, while another recalls faces with eyes running down their cheeks, Salvador Dal-style". Mr Gow and another serviceman had volunteered to take part in what they thought was research to find a cure for the common cold. Mr Gow felt that the government had never explained what happened to him. But now he has received an official admission for the first time, confirmed last night, that the intelligence agency MI6 tested LSD on servicemen. One of the scientists involved at the time suggested that the experiments were stopped because it was feared that the acid could produce "suicidal tendencies". MI6, known formally as the Secret Intelligence Service (SIS) and responsible for spying operations abroad, carried out the tests in the cold war in an attempt to uncover a "truth drug" which would make prisoners talk against their will in interrogations. In parallel experiments, the CIA infamously tested LSD and other drugs on unwitting human subjects in a 20-year search to uncover mind-manipulation techniques. The trials were widely criticised when they came to light in the 1970s.