Biographical Memoir of Sir John Leslie. 1 1 



lected at Largo all the necessary apparatus, he prosecuted with 

 ardour a series of experiments, which enabled him, in the years 

 1801 and 1802, to compose the bulk of his celebrated work on 

 Heat. In the latter year, " the gleam of peace," as he tells us 

 in his usual ornate style, " tempted him to indulge in a tempo- 

 rary suspension ; and to repair to the famed capital where the 

 treasures of art and science are so profusely displayed. In that 

 vortex of pleasure and centre of information, I spent," he adds, 

 " several months very agreeably ; but the work I had underta- 

 ken recalled my thoughts, and I hastened again to my retreat."* 

 His Experimental Inquiry into the Nature and Properties of 

 Heat was here at length completed. It was published at Lon- 

 don in the spring of 1804, in an octavo volume, with a dedica- 

 tion, couched in terms of strong and affectionate friendship, to 

 Mr Thomas Wedgwood, the companion of his studies at Et- 

 ruria, and of his first continental tour. The early death of that 

 ingenious and excellent person, whose delicate health is here 

 feelingly alluded to, was always mentioned by him as a public 

 as well as private misfortune. The originality and boldness of 

 the peculiar doctrines of the Inquiry^ and the number of new and 

 important facts disclosed by its singularly ingenious experimental 

 combinations, conspired to render it an object of extraordinary 

 interest throughout the scientific world ; and, indeed, it must 

 ever be viewed as constituting an era in the history of that re- 

 condite branch of Chemical science which forms its subject. 

 The Council of the Royal Society of London unanimously ad- 

 judged to its author the Rumford Medals appropriated as the 

 reward of discoveries regarding the nature of heat. As a phi- 

 losophical disquisition, it is far, however, from being perfect. 

 Its hypotheses are not warranted by the sober maxims of induc- 

 tive logic ; and its method and style are alike liable to serious 

 criticism. But it would be difficult to name any work in the 

 whole range of modern science more strongly indicative of a vi- 

 gorous and inventive genius ; and it must be allowed by all, 

 that its skilful experiments, and its large stock of new observa- 

 tions, far more than atone for its questionable theories, and for 

 that desultory arrangement, and those ambitious modes of ex- 



• Preface to the Inquiry on Heat. 



