The only son of Alexander Maconochie of Meadowbank,
Kirknewton,
Midlothian, and his wife Isabella Allan, daughter of the Rev. Walter Allan, minister of
Colinton in the same shire, was born on 26 January 1748. He was educated privately by
Alexander Adam and at the
High School of Edinburgh. He entered the
University of Edinburgh, where he attended the law classes. He was apprenticed to Thomas Tod,
writer to the signet. In 1764, Maconochie, with
William Creech,
John Bruce,
Henry Mackenzie, and two other fellow-students, founded the
Speculative Society, devoted to
public speaking and
liberal thought. Having completed his university course in 1768, Maconochie went to Paris for a short time. He
passed advocate on 8 December 1770 and was admitted as a student of
Lincoln's Inn (16 April 1771), but was not called to the
English bar. He subsequently returned to France, where he remained till 1773. In 1774, he was elected to the
general assembly as
lay representative of the burgh of
Dunfermline. Maconochie was appointed professor of
public law and
law of nature and
nations in the University of Edinburgh on 16 July 1779; and on 18 December following was elected treasurer of the
Faculty of Advocates. In 1783 he was one of the co-founders of the
Royal Society of Edinburgh. He served as the Society's Vice President 1812 to 1816. In 1788 (until 1796) he became
Sheriff-depute of Renfrewshire. He was one of the eight advocates who took an active part in procuring the rejection of
Henry Erskine as dean of the faculty in January 1796. He was then living at 5
George Square, Edinburgh. He succeeded
Alexander Abercromby as an ordinary
Lord of Session, and took his seat on the bench as Lord Meadowbank, on 11 March 1796. In the same year, he resigned his professorship. Maconochie was appointed a
Lord of Justiciary in place of
David Smythe of Methven on 4 September 1804, and was constituted one of the three lords commissioners of the newly appointed jury court on 9 May 1815. In a secret ruling in 1810 and 1812, on the case of
Marianne Woods and Jane Pirie v Dame Helen Cumming Gordon he related lesbian sexuality as being as fantastical as
witchcraft, and that it was 'notorious' that British Empire children's minds were lewdly influenced by Indian servants. His health, however, was poor, and he took little part in the proceedings of the new court, which was opened for the first time on 22 January 1816. He died at Coates House in
Dalry, Edinburgh on 14 June 1816, aged 68, and was buried in the private burial-ground of his house and estate, the
Meadowbank estate, in the parish of
Kirknewton, where there was a monument to his memory. Maconochie was considered an able judge, but eccentric. His predilection for Latin quotation was caricatured in the ‘Diamond Beetle Case,’ attributed to
George Cranstoun, Lord Corehouse. ==Works==