the various forms of delirium, and brought forward many cases not depending upon inflammation or other morbid conditions of the brain, but due rather to exhaustion and an abnormal condition of the blood. He showed that in cases of this class the delirium was increased by bleeding and lowering remedies, while a supporting treatment, ammonia and stimulants, was followed by relief.
Todd’s contributions to medical science were numerous. In 1832 he projected, with Dr. Grant of University College, London, ‘The Cyclopædia of Anatomy and Physiology.’ This work, of six thousand pages with numerous illustrations, was edited by him, and was only completed a short time before his death. He contributed many important articles, especially those on the heart, the brain, and nervous system. Among the other eminent contributors were Sir Richard Owen, Sir William Bowman, Sir James Paget, and Sir John Simon. The first number was published in June 1835. It was completed in 1859. This cyclopædia did more to encourage and advance the study of physiology and comparative and microscopic anatomy than any book ever published. Todd’s other publications were: 1. ‘Gulstonian Lectures on the Physiology of the Stomach,’ 1839 (‘London Medical Gazette’). 2. ‘Physiological Anatomy and Physiology of Man,’ 1843-56, with W. Bowman; this work was among the first physiological works in which an important place was given to histology—the accurate description of the structure of the various organs and tissues as displayed by the microscope. 3. ‘Practical Remarks on Gout, Rheumatic Fever, and Chronic Rheumatism of the Joints,’ 1843. 4. ‘Description and Physiological Anatomy of the Brain, Spinal Cord, and Ganglions,’ 1845. 5. ‘Lumleian Lectures on the Pathology and Treatment of Delirium and Coma,’ 1850 (‘London Medical Gazette’). 6. ‘Clinical Lectures,’ 3 vols. 1854-7-9 (2nd ed. Edited by Dr. Lionel Beale in one vol., 1861). Todd also contributed memoirs and papers to the ‘Transactions’ of the Royal Medical and Chirurgical Society from 1833 to 1859, and ten articles to the ‘Cyclopædia of Medicine,’ 1833 to 1835, of which the most important are on paralysis, on pseudo-morbid appearances, on suppuration, and on diseases of the spinal marrow.
A statue of Todd, by Noble, was erected by his friends in the great hall of King’s College Hospital.
[In Memoriam R.B. Todd, by Dr. Lionel Beale, 1870; obituary notice in the Times, February 1860, written by Sir W. Bowman, and the latter address on surgery, British Medical Association, 1866; obituary notices in British Medical Times and Gazette, British Medical Journal, and Proceedings of the Royal Society; Memoir of Sir W. Bowman by H. Power.]
TODHUNTER, ISAAC (1820-1884), mathematician, was second son of George Todhunter, independent minister of Rye, Sussex, and Mary, his wife, whose maiden name was Hume. Isaac was born on 23 Nov. 1820. His father’s death in 1826 left the family in narrow circumstances and the mother opened a school at Hastings. Isaac, who as a child was ‘unusually backward,’ was sent to a school in the same town kept by Robert Carr, and subsequently to one newly opened by Mr. J. B. Austin from London; by the influence of this latter teacher his career was largely determined. He next became assistant master at a school at Peckham, and while thus occupied managed to attend the evening classes at University College, London, where he had for his instructors Key, Malden, George, Long, and Augustus De Morgan, to all of who he always held himself greatly indebted, but especially to the last. In 1842 he graduated B.A. and obtained a mathematical scholarship in the university of London, and, on proceeding M.A., obtained the gold medal awarded for that examination. Concurrently with these studies he filled the post of mathematical master in a large school at Wimbledon conducted by Messrs. Stoton and Mayer.
In 1844, acting on De Morgan’s advice, he entered at St. John’s College, Cambridge. In 1848 he gained the senior wranglership and the first Smith’s prize, as well as the Burney prize. In the following year he was elected fellow of his college. From this time he was mainly occupied as college lecturer and private tutor, and in the compilation of the numerous mathematical treatises, chiefly educational, by which he became widely known. Of these, his Euclid (1st ed. 1862), a judicious mean between the symbolism of Blakelock and the verbiage of Potts, attained an enormous circulation; while his algebra (1858), trigonometry, plane and spherical (1859), mechanics (1867), and mensuration (1869), all took the place which they for the most part still retain as standard text-books. No mathematical treatises on elementary subjects probably ever attained so wide a circulation; and, being adopted by the Indian government, they were translated into Urdu and other Oriental languages. He was elected F.R.S. in 1862, and became a member of the Mathematical Society of London in 1865, the first year of its existence.