the late Judge liargreave, " in consideration of their eminent services in 

 the advancement of mathematical science." Late in the year 1853 Dr. 

 Boole brought to its close a labour on which he had bestowed a vast 

 amount of profound and patient thought. His Mathematical Analysis 

 of Logic " was written hastily, and on this account he afterwards regretted 

 its publication ; but the work which he now gave to the world must be 

 regarded as the most carefully matured of all his productions. It is 

 entitled "An Investigation of the Laws of Thought, on which are founded 

 the Mathematical Theories of Logic and Probabihties." The principle on 

 which the investigation proceeds is essentially the same as that enunciated 

 bj^the author in his earlier logical essays ; but, as he himself remarks, " its 

 methods are more general, and its range of applications far wider." This 

 great v/ork was published in 1854. 



During the remaining ten years of his life he contributed to various 

 scientific journals papers on Probabilites, on Partial Differential Equations, 

 on the Comparison of Transcendents, and on other high mathematical sub- 

 jects. He also produced two text-books, one on ' Differential Equations,' 

 and one on 'Finite Differences' — works which display a vast amount of 

 original research as well as an extensive acquaintance with the writings of 

 others. These have become class-books at Cambridge. 



In 1855 Dr. Boole was married to Miss Mary Everest, daughter of the 

 late Rev. T. R. Everest, Rector of Wickwar, Gloucestershire, and niece of 

 Colonel Sir George Everest, F.R.S., lately deceased, as also of Dr. Ryall, 

 the Vice-President and Professor of Greek in Queen's College, Cork. 

 The union was one of great mutual happiness, and was blessed with a 

 family of five daughters. 



In 1857 Dr. Boole communicated to the Royal Society of Edinburgh a 

 memoir " On the Application of the Theory of Probabilities to the Ques- 

 tion of the Combination of Testimonies or Judgments." For this purpose 

 there was awarded to him the Keith Medal, the highest honour in the 

 shape of prize which that Society has at its disposal. In June of the same 

 year he was elected a Fellow of this Society. At the Oxford Commemo- 

 ration in 1859 he received the honorary degree of D.C.L. 



Soon after the publication of his Treatise on Differential Equations, 

 Professor Boole resolved that if a new edition of the work should be called 

 for he would reconstruct it on a more extended scale. For several suc- 

 ceeding years his studies and researches were largely inspired and directed 

 by this object, which, however, he did not live to accomplish. The trea- 

 tise had been for some time out of print, and he was engaged in preparing 

 a new and enlarged edition when he was suddenly struck by the hand of 

 death. 



He had walked from his residence at Ballintemple to the College in 

 Cork, a distance of little more than two miles, in a drenching rain, and 

 lectured in his wet clothes. The result was a feverish cold, which soon 



