181 



It would be impossible, in the very short compass within which 

 this notice is necessarily confined, to enumerate even a small part 

 of the publications of an author whose pursuits were so vai4ous 

 and whose labours were so unremitting. He contributed papers 

 to our Transactions in 1797 and 1803 ; the first containing an ex- 

 planation of some optical experiments of Lord Brougham, and the 

 second, some remarks on heat and on the action of bodies which inter- 

 cept it, with reference to a paper by Dr. Herschel ; and in 1 806, he 

 became one of the foreign members of our body. In 1799, he ob- 

 tained the first accessit for an essay Sur Vinjiuence des signes rela- 

 tivement a la formation des idees, which was written for a prize, 

 adjudged to the celebrated Degerando, proposed by the Institute 

 of France ; and he was shortly afterwards elected a corresponding 

 member of that body. His Essais de philosophie, et etudes de V esprit 

 humain, appeared in 1804-, to whicii were appended some veiy re- 

 markable Essays of his friend and ancient preceptor Le Sage, of 

 whom he published a most interesting life in the following year. 

 He likewise published, in very rapid succession, translations of the 

 Hhetoric of Blair, the Essays and posthumous works of Adam Smith, 

 the Elements of Philosophy of Dugald Stewart, the essay on Popu- 

 lation by Malthus, Salt's Travels in Abyssinia, the Conversations on 

 Political Economy, of his wife's sister-in-law, Mrs. Marcet, and many 

 other works of less importance and interest. 



In 1823, at the age of 72, though still vigorous and active both 

 in body and mind, he resigned the professorship of natural philo- 

 sophy, in wise anticipation of the approach of that period of life 

 when men naturally feel reluctant to acknowledge the decline of 

 their faculties, or incompetent to perceive it. From this time, 

 though still consulted by his colleagues and fellow-citizens on every 

 important subject connected with the Academy or the state, he re- 

 tired into the bosom of his family, which contained within itself, in 

 a verv' uncommon degree, every element of tranquillity, contentment 

 and happiness. His own temper was singularly equable and tran- 

 quil ; and his tastes and pursuits, which rarely left his time unoc- 

 cupied, saved him from that tcediiun vitcB which sometimes renders 

 old age querulous and discontented. Thus happily disposed and 

 happily circumstanced, it is not wonderful that his life should have 

 been prolonged beyond the ordinary limits of humanity. He died 

 on the 8th of April, in the 88th year of his age, surrounded by his 

 family, and deeply regretted by all who knew him. 



The philosophical character of M. Prevost had been greatly influ- 

 enced by that of his master Le Sage, a man of great originality and 

 profundity of thought, but whose speculations, particularly those 

 which attempted the explanation of the cause of gravity, trespassed 

 somewhat beyond the proper limits of philosophy. We consequentlv 

 find him disposed to explain the laws of the propagation of heat and 

 light on the most simple mechanical principles, and to trace their 

 origin and progress much farther than the experiments or facts will 

 properly warrant ; thus giving to his conclusions, in many cases, a 

 much more hypothetical character than would otherwise" have at- 



