Scottish explorer of eastern equatorial Africa, born at Nairn, where his father was the parish minister, on the 11th of April 1827. He was educated at the grammar school and Marischal College, Aberdeen, and in 1846 joined the Indian army. He saw active service in the Sikh War (184849), served throughout the mutiny of 1857, and was wounded in the operations for the relief of Lucknow. He returned to England in 1858, and in 1860 joined J. H. Speke in the memorable expedition which solved the problem of the Nile sources. The expedition left Zanzibar in October 1860 and reached Gondokoro, where the travellers were again in touch with civilization, in February 1863. Speke was the leader, but Grant carried out several investigations independently and made valuable botanical collections. He acted throughout in absolute loyalty to his comrade. In 1864 he published, as supplementary to Spekes account of their journey, A Walk across Africa, in which he dealt particularly with the ordinary life and pursuits, the habits and feelings of the natives and the economic value of the countries traversed. In 1864 he was awarded the patrons medal of the Royal Geographical Society, and in 1866 given the Companionship of the Bath in recognition of his services in the expedition. He served in the intelligence department of the Abyssinian expedition of 1868; for this he was made C.S.I. and received the Abyssinian medal. At the close of the war he retired from the army with the rank of lieutenant-colonel. He had married in 1865, and he now settled down at Nairn, where he died on the 11th of February 1892. He made contributions to the journals of various learned societies, the most notable being the Botany of the Speke and Grant Expedition in vol. xxix. of the Transactions of the Linnaean Society.