Why a British MP was filmed taking mescaline

# Warning: This programme contains descriptions of drug use # In 1955 Christopher Mayhew MP took the hallucinogenic drug mescaline for a TV experiment. We look back at the history of psychedelic research and speak to Dr Robin Carhart-Harris, head of the Centre for Psychedelic Research at Imperial College London. Plus, the battle to legalise contraception in Ireland, a pro-democracy activist in China, the chemical and biological weapons programme in apartheid South Africa, and why thousands of Jews secretly fled Iraq in the 1970s.