XXVll 



John T. Graves, M.A., F.R.S., was son of John C. Graves, of Dublin, 

 Barrister-at-Law. He was born in Dublin on the 4th of December, 1806, 

 and passed some years in the school of the Rev. Samuel Field, Westbury- 

 on-Trym, Somersetshire. He entered Trinity College, Dublin, in 1823, 

 and was a class-fellow of Sir William Rowan Hamilton, with whom, though 

 living at a distance, he kept up a life-long friendship. In his under- 

 graduate career he was distinguished in both Science and Classics, and at 

 his Degree Examination in 1827 was awarded the Classical Gold Medal. 

 He soon after took an ad eundem degree at Oxford, and was incorporated 

 in Oriel College, where he resided some time, and proceeded to the degree 

 of M.A. He was also M.A. of Dublin University. On the 10th of June, 

 1831, he was called to the Bar as a Member of the Inner Temple, and for 

 a short time went the Western circuit. In the year 1839 he was appointed 

 Professor of Jurisprudence in University College, London, in succession to 

 Mr. Austin, and not long after was elected to be Examiner in Laws 

 in the University of London. The records of his work as a lawyer 

 are Twelve Lectures on the Law of Nations, published in the ' Law Times,** 

 commencing April 25, 1845, and two elaborate articles contributed to 

 the ( Encyclopaedia Metropolitana,' on Roman Law and Canon Law. About 

 this time he was a contributor to Smith's Dictionary of Greek and Roman 

 Biography and Mythology. Among other articles from his pen are those 

 on Cato, Crassus, Drusus, Gaius, and the Legislation of Justinian. 



As a scientific author Mr. Graves commenced his labours in his twentieth 

 year. It was in October 1826 that he was engaged in researches on 

 profound and subtle questions in analysis ; the results he obtained were 

 communicated to the Royal Society of London in the year 1828, and pub- 

 lished in the Philosophical Transactions for 1829, under the title "An 

 attempt to rectify the Inaccuracy of some Logarithmic Formulas." This 

 paper gave rise to interesting and important discussions, with which the 

 names of M.Vincent, Peacock, Ohm, De Morgan, Warren, Rowan Hamilton, 

 and others are connected. It was by meditating upon the results of this 

 memoir that Sir W. Rowan Hamilton was led to his ingenious theory of 

 Conjugate Functions or Algebraic Couples, as may be learned from Sir 

 W. R. Hamilton's abstract of a paper " On Conjugate Functions, or 

 Algebraic Couples, as tending to illustrate generally the Doctrines of 

 Imaginary Quantities, and as confirming the Results of Mr. Graves respect- 

 ing the existence of two Independent Integers in the complete expression 

 of an Imaginary Logarithm," as well as from an abstract of a " Memoir on 

 the Theory of Exponential Functions," both published in the Report of the 

 British Association for 1834. In continuation of the same and allied re- 

 searches, Mr. Graves contributed a paper to the Philosophical Magazine 

 for April 1836, "On the lately Proposed Logarithms of Unity, in reply to 

 Prof. De Morgan ;" and in November and December of the same year 

 another, entitled " Explanation of a remarkable Paradox in the Calculus of 

 Functions, noticed by Mr. Babbage." To the same journal were contti- 



