BBC 1, Wednesdays at 10 35 pm from 14 to 28 July

Rating:

Each of these three documentaries, which focus on rare medical conditions, is rather like a whodunit, where the mystery unfolds, is subsequently investigated, and, in a sense, solved.

The first episode covered the much debated madness of King George III. Professors Tim Cox of Addenbrooke's Hospital, Cambridge, and Martin Warren of Queen Mary's, London, set out to find the truth about the king's condition, which is widely thought to have been caused by acute intermittent porphyria. The story began with the recent unearthing of samples of the king's hair in a London museum vault. The hair was analysed and found to have 300 times the amount of arsenic when compared with controls. Painstaking searches through the history books revealed a number of odd findings: that many creams and oral therapies contained arsenic in the 18th century; that a distant relative of the king, who also had symptoms of porphyria, was once therapeutically injected with …