Newton’s interest in alchemy has long been known. He read widely and made innumerable experiments, as a practising alchemist, Newton spent days locked up in his laboratory. The scope and details of that moonlighting enterprise are only now becoming clear, as science historians gradually analyse and publish Newton’s extensive writings on alchemy — a million-plus words from the Newtonian archives that had previously been largely ignored.

The papers horrified Keynes, when he purchased some of them in the 1930’s. To quote Keynes writings on Newton –the Man:

"In the eighteenth century and since, Newton came to be thought of as the first and greatest of the modern age of scientists, a rationalist, one who taught us to think on the lines of cold and untinctured reason. I do not see him in this light. I do not think that anyone who has pored over the contents of that box which he packed up when he finally left Cambridge in 1696 and which, though partly dispersed, have come down to us, can see him like that. Newton was not the first of the age of reason. He was the last of the magicians, the last of the Babylonians and Sumerians, the last great mind which looked out on the visible and intellectual world with the same eyes as those who began to build our intellectual inheritance rather less than 10,000 years ago. Isaac Newton, a posthumous child born with no father on Christmas Day, 1642, was the last wonder child of whom the Magi could do sincere and appropriate homage.”

Some have suggested that he finally succeeded in transmuting lead into gold. So that might explain why at the height of his career, instead of accepting a professorship at Cambridge, he was appointed Director of the Mint with the responsibility of securing and accounting for England's repository of gold. What the research yielded is inconclusive. His servants record: "He very rarely went to bed until two or three of the clock, sometimes not till five or six, lying about four or five hours, especially at springtime or autumn, at which time he used to employ about six weeks in his laboratory, the fire scarce going out night or day."

Newton, who is revered as the founder of modern science and the mechanistic universe, stands out as one of the greatest spiritual alchemists of all time. To quote Manuel’s Religion of Isaac Newton: "The more Newton's theological, alchemical, chronological and mythological work is examined as a whole corpus, set by the side of his science, the more apparent it becomes that in his moments of grandeur he saw himself as the last of the interpreters of God's will in actions, living on the fulfilment of times."

Newton kept his alchemy secret. He wrote to fellow alchemist Robert Boyle a letter urging him to keep 'high silence' in publicly discussing the principles of alchemy. "Because the way by the Mercurial principle may be impregnated has been thought fit to be concealed by others that have know it and therefore may possibly be an inlet to something more noble that is not to be communicated without immense damage to the world if there be any verity in [the warning of the] Hermetic writers. There are other things besides the transmutation of metals which none but they understand." Newton never published a work on alchemy. Can it be concluded that he knew he had failed at Alchemy or that he had enough success to think that he might be on the track of something of fundamental importance and wished to keep the discovery secret?

Some clue about may lie in the influence of Lord Jeffreys, who was serially Lord Chief Justice and Lord Chancellor during the time of Newton’s experiments. The Whig view of history as portrayed by McCauley and countless imitators since the 19th Century paints a picture of Lord Jeffries as a drunken and debauched sadist. In fact he was protecting the Stuart succession after the economic and social turmoil of the Commonwealth period. However, he did punish Witchcraft, which was still a criminal offence very vigorously. Following the Monmouth Rebellion and the Battle of Sedgemoor a 70 year old dowager was accused of hiding two fugitives. Jeffreys condemned her despite her age. Her sentence was to be burned to death, suggesting that Jeffreys took her to be a witch. In fact, the sentence was commuted to beheading- she is now one of the many headless ghosts of Britain. Jeffreys took an equally jaundiced view of the sort of experiments in which Newton engaged- a sort of male form of witchcraft. He was no respecter of rank, when he had to address issues that challenged Political, Social or Economic stability of the Stuart Succession. Alchemy would certainly have been perceived to challenge the economic stability of the Stuart Monarchy.