Thomas-Fantel de Lagny (1660–1734) This lesser known French mathematician wrote on extracting roots, binary arithmetic and methods in problem solving. It said that when found unconscious on his death bed, he was asked for the square of 12. In response, de Lagny rose in bed, gave the answer, and immediately passed away.	Leonhard Euler (1707–1783) Euler’s name is attached to every branch of mathematics. He retained his creativity and mental powers right up to his death. On that last day, he had been calculating the laws of ascent of balloons, and working on the orbit of Uranus. Then, playing with his grandson, he suffered a stroke. His pipe fell from his hand, and he uttered ‘I die.’
Georg Cantor (1845–1918) Georg Cantor made a lasting contribution to modern set theory, but his ideas were bitterly opposed by Kronecker at the time. So much so, that the timid, sensitive Cantor spent much of his life in a mental hospital, where he finally died.	Pierre-Simon Laplace (1749–1827) The last words of Laplace before he died are reported to have been: ‘What we know is very slight; what we don’t know is immense.’