LATHAM, PETER MERE, M.D. (1789–1875), physician, second son of Dr. John Latham (1761–1843) [q.v.] and Mary Mere, was born in Fenchurch Buildings, London, on 1 July 1789. His first education was at the free school of Sandbach, Cheshire, but in 1797 he was sent to Macclesfield grammar school, of which his uncle was head-master, and thence in 1806 to Brasenose College, Oxford. He obtained the chancellor's prize for Latin verse, on 'Corinth,' in 1809, and graduated B.A. 21 May 1810, M.A. 1813, M.B. 1814, and M.D. 1816. He began his medical studies at St. Bartholomew's Hospital in 1810. It was then the custom for an intending physician to attach himself to one of the medical staff, and he chose Dr. Haworth, a member of his own college. He was elected a fellow of the College of Physicians on 30 Sept. 1818, and delivered the Gulstonian lectures in 1819. He took a house in Gower Street, and in 1815 was elected physician to the Middlesex Hospital, which office he held till November 1824, when he was elected physician to St. Bartholomew's Hospital. In March 1823 he was asked by the government to undertake the investigation of an epidemic disorder then prevalent at the Millbank Penitentiary, and in 1825 published 'An Account of the Disease lately prevalent at the General Penitentiary.' Scurvy with diarrhœa and curious subsequent nervous disorders were the main features of the epidemic. More than half the prisoners were affected, and Latham, with Dr. Peter Mark Roget [q.v.], proved that it was due to a too scanty diet. They recommended at least one solid meal every day, better bread, and three half-pounds of meat for every prisoner every fortnight. This improved regimen put an end to the epidemic. In 1828 he published in the 'Medical Gazette' 'Essays on some Diseases of the Heart,' in which he maintained that the administration of mercury till salivation was produced was essential to the cure of pericarditis. In June 1836 he was elected, with Dr. Burrows, joint lecturer on medicine in the school of St. Bartholomew's Hospital (Manuscript Minute-book of Medical School). His lectures were delivered in a slow and formal style, but commanded attention from the full information they contained (information from Sir G. M. Humphry, a former attendant of the lectures). In the same year he published 'Lectures on Subjects connected with Clinical Medicine.' The first six are on methods of study and of observation, six more on auscultation and percussion, and two on phthisis. He made careful notes of his cases, and sixty folio volumes of these are in the library of St. Bartholomew's Hospital. His clinical teaching was excellent. He was appointed physician extraordinary to the queen in 1837, but never attained a very large practice. In 1839 he delivered the Harveian oration at the College of Physicians, and it was published with a dedication to Sir Henry Halford and the fellows. His descriptions of the merits of Sydenham, Sir Thomas Browne, Morton, and Arbuthnot are admirable, while his Latin style is above the average level of such compositions. He also delivered the Lumleian lectures, and was three times censor—1820, 1833, and 1837. In 1845 he published 'Lectures on Clinical Medicine, comprising Diseases of the Heart,' a work of great originality, full of careful observation, and containing a discussion of all parts of the subject. Pericarditis was unknown to him except as part of acute rheumatism, and he held that a murmur taught an observer no more than whether the inside or the outside of the heart was diseased; but his remarks on functional palpitation and on the cardiac physical signs in cases of phthisis have not been superseded, and deserve high praise. He treated acute rheumatism by bleeding, calomel, and opium, but was opposed to copious venesection. His discussion of the symptoms and post-mortem appearances of angina pectoris in relation to the case of Dr. Thomas Arnold of Rugby School is a model of the best kind of clinical dissertation, and though some of the thirty-eight lectures are now obsolete, they contain information of permanent value, and also repay study as examples of method.
He had extreme emphysema at a somewhat early age, and with it frequent attacks of asthma. These forced him in 1841 to resign his physiciancy at St. Bartholomew's, but he continued his private practice till 1865, when he left London and settled at Torquay, where he resided till his death, 20 July 1875. He was a small man, with bright grey eyes and a large aquiline nose, and with a pleasing voice. His portrait was painted by John Jackson (1778–1831) [q.v.]. He married Diana Clarissa Chetwynd Stapleton in 1824, but she died in the following year (monument in the church of St. Bartholomew the Less). He afterwards married Grace Mary Chambers, and had four children.