XXV111 



buted by him, in September 1838, a New and General Solution of Cubic 

 Equations ; in August 1839 a paper on the Functional Symmetry ex- 

 hibited in the Notation of certain Geometrical Porisms when they are 

 stated merely with reference to the arrangement of points ; and in 

 April 1845 a paper on a Connexion between the General Theory of Nor- 

 mal Couples and the Theory of Complete Quadratic Functions of Two 

 Variables. A subsequent number contains a contribution on the Rev. 

 J . G. MacVicar's Experiment on Vision ; and the Report of the Cheltenham 

 Meeting of the British Association contains abstracts of papers communi- 

 cated by him on the Polyhedron of Forces, and on the Congruence nx= 

 (mod.p). 



The above list of papers, itself incomplete, is far from representing ade- 

 quately Mr. J. T. Graves's contributions to mathematical science. The 

 Transactions of the Royal Irish Academy contain many traces of his in- 

 tellectual activity ; and by his long correspondence with Sir William Rowan 

 Hamilton, commenced at an early period and maintained until death in- 

 terposed, Mr. Graves may be said to have taken no small part in bring- 

 ing to maturity the splendid conception of Quaternions, by which alone 

 the name of Hamilton would have been rendered immortal. In his pre- 

 face to the c Lectures on Quaternions,' Sir William makes frequent allusion 

 to the suggestive character of his correspondence with his early friend, 

 and warmly expresses his indebtedness thereto. 



Mr. Graves was one of the Committee of the Society for the Diffusion 

 of Useful Knowledge. In the year 1839 he was elected a Fellow of the 

 Royal Society, and he subsequently served upon its Council. He was also 

 a Member of the Philological Society and of the Royal Society of 

 Literature. 



For many years past he had taken interest in forming a collection of 

 mathematical works of all ages and countries, a collection which, though 

 only to be appreciated by the few, is by those qualified, who are acquainted 

 with it, considered to be almost unique for historical curiousness and com- 

 pleteness ; and nearly every book composing it was bound under his direc- 

 tion with costly care and elegance. This portion of his library he be- 

 queathed to University College, London, in remembrance of his former 

 connexion as Professor with that Institution. 



In the year 1846, soon after his marriage with the daughter of the late 

 William Tooke, Esq., F.R.S., he was appointed Assistant Poor-Law Com- 

 missioner, and on the constitution of the present Board in 1847 was 

 made Poor-Law Inspector. He served efficiently in that department 

 till the past month, when he sent in his resignation, an act which he did 

 not long survive. He died on the 29th of March, at his residence in 

 Cheltenham, at the age of 63. 



