John Keill FRS (1 December 1671 – 31 August 1721) was a Scottish mathematician, natural philosopher, and cryptographer who was an important defender of Isaac Newton. Biography Keill was born in Edinburgh, Scotland on 1 December 1671. His father was Robert Keill, an Edinburgh lawyer. His mother was Sarah Cockburn. His brother, James Keill, became a noted physician. Keill studied at Edinburgh University under David Gregory. In 1692, he obtained his bachelor's degree with a distinction in physics and mathematics. Keill then attended Balliol College, Oxford, obtaining an MA on 2 February 1694. After being appointed a lecturer in experimental philosophy at Hart Hall, Keill started giving lectures and performing experiments based on Newton's findings. He instructed his students on the laws of motion, the principles of hydrostatics and optics, and Newtonian propositions on light and colours. In 1698. Keill published Examination of Dr. Burnet's Theory of the Earth. His volume contained scientific attacks on Burnet, René Descartes, Baruch Spinoza, Thomas Hobbes and Nicolas Malebranche. This publication, along with his teaching, gained Keill notice in the English academic community. In 1700, he was elected a Fellow of the Royal Society. However, after failing to get an academic appointment at Oxford in 1709, Keill left the university to seek a government position. In 1709, Keill was appointed treasurer of a charitable fund to resettle war refugees from the German states. He accompanied at least one group of German refugees to the British Province of New York. In 1711, Keill accepted the position of decypherer to Anne, Queen of Great Britain. His responsibilities included explaining old manuscripts to the sovereign. In 1712, Keill returned to Oxford as Savilian Professor of Astronomy. On 9 July 1713, he was awarded the DM degree. In his later years, Keill became involved in the controversy regarding Gottfried Leibniz's alleged plagiarisation of Newton's invention of calculus, serving as Newton's chief defender. However, Newton himself eventually grew tired of Keill as he stirred up too much trouble. In 1717, Keill married Mary Clements, a woman 25 years his junior and the daughter of an Oxford bookbinder. The marriage created great scandal at the time as Clements was from a lower class. On 31 August 1721, Keill died in London from a sudden illness, possibly food poisoning. It was stated in the old Dictionary of National Biography that Keill left no will. His will is referenced in the Oxford