26 Biographical Memoir of Sir John Leslie. 



of light ; and I was only called at times to look out, by the bab- 

 bling chant of the Monks, with their torches and crosses, carrying 

 the dead to their graves, and followed by the Charitable Breth- 

 ren, like ghosts, apparelled in white sheets, with only holes for 

 their eyes. They seemed better fitted to terrify the living than 

 to comfort the dying." Two years after this, he made another 

 tour on the continent, in which he seems only to have gone over 

 ground in France, the Netherlands, and Holland, which for the 

 most part he had traversed before. This, we believe, was the 

 last of his journeys abroad. 



The only important production of Mr Leslie's latter years was 

 that which formed his crowning benefaction to this Encyclopjedia 

 — his Discourse on the Progress of Mathematical and Physical 

 Science during the eighteenth century ; which, with others of a si- 

 milar description, constitute its first volume. The opening tribute 

 to Mr Playfair, of whose history of the earlier progress of these 

 sciences, this Discourse is a continuation, does honour alike to 

 the writer's candour and taste. " Tiie progress of mathematical 

 and physical science during the brillirnt period which closed with 

 Newton and Leibnitz, has,"" he says, " been traced with fidelity 

 and sustained interest by the hand of a master, whose calm judg- 

 ment weighed impartially the different claims of discovery, whose 

 powers of illustration could expand the fine results, and whose 

 luminous eloquence was commensurate with the dignity of the 

 subject." Nor is his observation on his own task less just; 

 namely, that the more crowded field of discovery which it pre- 

 sents rendered it one of increased difficulty ; — " its multifarious 

 materials often lying scattered among the countless volumes 

 of the Transactions of learned Societies." His arrangement 

 of these materials, and his view of the whole subject, is com- 

 prehensive, vigorous, and spirited; and the greater ease and 

 perspicuity of its style makes this the most agreeable perhaps 

 of all his writings. 



The volumes of the Edinburgh Philosophical Journal, pub- 

 lished between 1824 and 18!29, contain some small contributions, 

 which may be here mentioned as also belonging to his latter years. 

 The first consists of Remarks on the Light of the Moon and of 

 the Planets ; the second, of an Enumeration of the Instruments 

 requisite for Meteorological Observations ; the third, of a Letter 



