Explorer and naturalist. Born at Branziet (Baldernock, East Dunbartonshire), Buchanan was the third son of Thomas Buchanan of Spittal and Leny, and Elizabeth Hamilton of Bardowie. He attended school in Glasgow and then read medicine at the University of Edinburgh, graduating in 1783. He joined the navy as a ship's surgeon but soon retired due to ill health. In 1794, he was appointed a surgeon with the East India Company in Bengal (India). He was able to explore Burma, Chittagong (1798), the Andaman Islands, Nepal (1802-3) and North Bengal and Bihar (1807-9) and made detailed surveys of the botany, geography, agriculture, economy, social conditions and culture of these areas, preparing extensive reports which now form an important historical resource.
Between 1803-04 he served as surgeon to the Marquis of Wellesley, who was Governor-General of India. He managed a menagerie, founded by the Marquis, which later became the Calcutta Alipore Zoo and was appointed Superintendent of the Botanical Garden in Calcutta in 1814, succeeding William Roxburgh (1751 - 1815) who had sponsored one of Buchanan's earlier expeditions. Now a wealthy man, who had been publicly-recognised for his work, he returned to his Leny estate in Scotland the following year. He also inherited his mother's Bardowie estate, later adding her name to his in recognition of this.
His works include A Journey from Madras through the countries of Mysore, Canara and Malabar (1807, in three volumes), an Account of the Kingdom of Nepal (1819), A Genealogy of the Hindu Gods (1819) and An Account of the Fishes of the Ganges (1822), together with contributions to a number of scientific journals on botany and natural history.
He was elected a Fellow of the Royal Society of Edinburgh in 1817 and was appointed a Deputy Lieutenant of Perthshire in 1826. He died at Leny House near Callander, which he had inherited on the death of his elder brother.
