The eldest son of Thomas Latham, vicar of Billingborough, Lincolnshire, he was born there on 24 March 1812. He entered Eton College in 1819, and in 1829 went on to King's College, Cambridge, where he graduated B.A. in 1832, and was soon afterwards elected a Fellow.
Latham was more interested, however, in ethnology and philology. In 1849 he abandoned medicine and resigned his appointments. In 1852 he was given the direction of the ethnological department of The Crystal Palace, as it moved to Sydenham. Latham was a follower of James Cowles Prichard, and like Prichard took ethnology to be, in the main, the part of historical philology that traced the origin of races through the genealogical relationships of languages. He frequently lectured in this area. As a baseline he used the three-race theory ofGeorges Cuvier. Along with Prichard, however, Latham criticised Cuvier's use of the "Caucasian race" concept; and he preferred to avoid the term "race", referring instead to "varieties of man", as a reaction to the rise of polygenist theory around 1850. However, he followed in 1854 by writing The Native Races of the Russian Empire. Latham moved on, though, from Prichard's assumption, that the historical relationships of languages matched perfectly the relationships of the groups speaking them. In 1862 he made a prominent protest against the central Asian theory of the origin of the Aryan race. He supported views which were later advocated by Theodor Benfey, Parker, Isaac Taylor, and others. The origin of the Indo-European languages was, in Latham's view, in Lithuania; and he strongly attacked Max Müller, proponent of the "Aryan theory", at the same time as did John Crawfurd arguing from rather different premises. The controversy over Latham's views on Indo-European languages following his Comparative Philology did permanent damage to his scholarly reputation.
Later life
wrote in his memoirs of Latham's habit of pleading poverty and asking for money. In 1863 Latham obtained a civil list pension. In later life he was afflicted with aphasia, and died at Putney on 9 March 1888.
Works
In 1841 Latham produced a well-known text-book, The English Language. He devoted himself to a thorough revision of Samuel Johnson's Dictionary of the English Language, which he completed in 1870. He subsequently spent much time on a Dissertation on the Hamlet of Saxo Grammaticus and of Shakespeare. His works on the English language passed through many editions, and were regarded as authoritative till they were superseded by those of Richard Morris and Walter William Skeat. Other works included: