in the spring of 1843, and died in Edinburgh the following February, at 30 years of age. Gregory is buried with his siblings in his parents burial plot in the south-west corner of Canongate Kirkyard, next to Adam Smith. Family Gregory never married. He was the youngest son of eleven children. His older brother William, like his father, was a chemist and physician. His great-great-grandfather James Gregory, the mathematician, designed the Gregorian telescope. James's nephew, David Gregory, was appointed a professor of mathematics at the University of Edinburgh in 1683. Gregory lived together with his brothers and their wives in a huge Georgian townhouse, 10 Ainslie Place, on the Moray Estate in the western New Town of Edinburgh, originally their father's house. Published works Presentations made to the Cambridge Philosophical Society. 'On the real nature of symbolical algebra' – 14 May 1838. 'On the logarithms of negative quantities' – 26 November 1838. 'On photogenic drawings' – 22 April 1839 'On chemical classification' – 6 May 1839 The Mathematical Writings of D. F. Gregory, M.A., Ed. W. Walton, (Cambridge, 1865). Notes See also Commutative property Cyclic quadrilateral References Proceedings of the Cambridge Philosophical Society, vol. vii. October 28, 1889May 30, 1892, (Cambridge, 1892). 1813 births 1844 deaths People from Aberdeen People educated at Edinburgh Academy Alumni of the University of Edinburgh Fellows of Trinity College, Cambridge Scottish mathematicians Burials at the Canongate Kirkyard