Melvyn Bragg and guests discuss the origins, development and uses of chromatography. In its basic form, it is familiar to generations of schoolchildren who put a spot of ink at the bottom of a strip of paper, dip it in water and then watch the pigments spread upwards, revealing their separate colours. Chemists in the 19th Century started to find new ways to separate mixtures and their work was taken further by Mikhail Tsvet, a Russian-Italian scientist who is often credited with inventing chromatography in 1900. The technique has become so widely used, it is now an integral part of testing the quality of air and water, the levels of drugs in athletes, in forensics and in the preparation of pharmaceuticals.

With

Andrea Sella

Apryll Stalcup

And

Leon Barron

Melvyn Bragg and guests discuss the life, times and influence of Eleanor of Aquitaine (c1122-1204) who was one of the most powerful women in Twelfth Century Europe, possibly in the entire Middle Ages. She inherited land from the Loire down to the Pyrenees, about a third of modern France. She married first the King of France, Louis VII, joining him on the Second Crusade. She became stronger still after their marriage was annulled, as her next husband, Henry Plantagenet became Henry II of England. Two of their sons, Richard and John, became kings and she ruled for them when they were abroad. By her death in her eighties, Eleanor had children and grandchildren in power across western Europe. This led to competing claims of inheritance and, for much of the next 250 years, the Plantagenet and French kings battled over Eleanor's land.

With

Lindy Grant

Nicholas Vincent

And

Julie Barrau

Producer: Simon Tillotson.

Melvyn Bragg and guests discuss Thomas Paine and his pamphlet "Common Sense" which was published in Philadelphia in January 1776 and promoted the argument for American independence from Britain. Addressed to The Inhabitants of America, it sold one hundred and fifty thousand copies in the first few months and is said, proportionately, to be the best-selling book in American history. Paine had arrived from England barely a year before. He vigorously attacked monarchy generally and George the Third in particular. He argued the colonies should abandon all hope of resolving their dispute with Britain and declare independence immediately. Many Americans were scandalised. More were inspired and, for Paine's vision of America's independent future, he has been called a Founding Father of the United States.

With

Kathleen Burk

Nicholas Guyatt

And

Peter Thompson

Producer: Simon Tillotson.

Melvyn Bragg and guests discuss the planet Saturn with its rings of ice and rock and over 60 moons. In 1610, Galileo used an early telescope to observe Saturn, one of the brightest points in the night sky, but could not make sense of what he saw: perhaps two large moons on either side. When he looked a few years later, those supposed moons had disappeared. It was another forty years before Dutch scientist Christiaan Huygens solved the mystery, realizing the moons were really a system of rings. Successive astronomers added more detail, with the greatest leaps forward in the last forty years. The Pioneer 11 spacecraft and two Voyager missions have flown by, sending back the first close-up images, and Cassini is still there, in orbit, confirming Saturn, with its rings and many moons, as one of the most intriguing and beautiful planets in our Solar System.

With

Carolin Crawford

Michele Dougherty

And

Andrew Coates

Melvyn Bragg and guests discuss Tristan and Iseult, one of the most popular stories of the Middle Ages. From roots in Celtic myth, it passed into written form in Britain a century after the Norman Conquest and almost immediately spread throughout northern Europe. It tells of a Cornish knight and an Irish queen, Tristan and Iseult, who accidentally drink a love potion, at the same time, on the same boat, travelling to Cornwall. She is due to marry Tristan's king, Mark. Tristan and Iseult seemed ideally matched and their love was heroic, but could that excuse their adultery, in the minds of medieval listeners, particularly when the Church was so clear they were wrong?

With

Laura Ashe

Juliette Wood

And

Mark Chinca

Producer: Simon Tillotson.

Melvyn Bragg and guests discuss the eminent 19th-century scientist Michael Faraday. Born into a poor working-class family, he received little formal schooling but became interested in science while working as a bookbinder's apprentice. He is celebrated today for carrying out pioneering research into the relationship between electricity and magnetism. Faraday showed that if a wire was turned in the presence of a magnet or a magnet was turned in relation to a wire, an electric current was generated. This ground-breaking discovery led to the development of the electric generator and ultimately to modern power stations. During his life he became the most famous scientist in Britain and he played a key role in founding the Royal Institution's Christmas lectures which continue today.

With:

Geoffrey Cantor

Laura Herz

Frank James

Producer: Victoria Brignell.

Melvyn Bragg and his guests discuss the evolution and role of Circadian Rhythms, the so-called body clock that influences an organism's daily cycle of physical, behavioural and mental changes. The rhythms are generated within organisms and also in response to external stimuli, mainly light and darkness. They are found throughout the living world, from bacteria to plants, fungi to animals and, in humans, are noticed most clearly in sleep patterns.

With

Russell Foster

Debra Skene

And

Steve Jones

Melvyn Bragg and guests discuss the origins and rise of Legalism in China, from the start of the Warring States Period (c475 - 221 BC) to the time of The First Emperor Qin Shi Huang (pictured), down to Chairman Mao and the present day. Advanced by the Qin statesman Shang Yang and later blended together by Han Fei, the three main aspects of Legalism were the firm implementation of laws, use of techniques such as responsibility and inscrutability, and taking advantage of the ruler's position. The Han dynasty that replaced the Qin discredited this philosophy for its apparent authoritarianism, but its influence continued, re-emerging throughout Chinese history.

With

Frances Wood

Hilde de Weerdt

And

Roel Sterckx

Producer: Simon Tillotson.

Melvyn Bragg and guests discuss the scientific advances made in the three voyages of Captain James Cook, from 1768 to 1779. Cook's voyages astonished Europeans, bringing back detailed knowledge of the Pacific and its people, from the Antarctic to the Bering Straits. This topic is one of more than a thousand different ideas suggested by listeners in October and came from Alysoun Hodges in the UK, Fiachra O'Brolchain in Ireland, Mhairi Mackay in New Zealand, Enzo Vozzo in Australia, Jeff Radford in British Columbia and Mark Green in Alaska.

With

Simon Schaffer

Rebekah Higgitt

And

Sophie Forgan

Producer: Simon Tillotson.

Melvyn Bragg and guests discuss the outbreak of witch trials in Massachusetts in 1692-3, centred on Salem, which led to the execution of twenty people, with more dying in prison before or after trial. Some were men, including Giles Corey who died after being pressed with heavy rocks, but the majority were women. At its peak, around 150 people were suspected of witchcraft, including the wife of the governor who had established the trials. Many of the claims of witchcraft arose from personal rivalries in an area known for unrest, but were examined and upheld by the courts at a time of mass hysteria, belief in the devil, fear of attack by Native Americans and religious divisions.

With

Susan Castillo-Street

Simon Middleton

And

Marion Gibson

Producer: Simon Tillotson.