S16 Biographical Memoir ofDr Prmtley. 



philosoj^y, chemistry, vegetable and animal physiology, have 

 scarcely a single phenomenon in their range that they can com- 

 pletely explain without it. 



It is but a slight sketch that I have here presented of the 

 most remarkable discoveries of Priestley ; want of time forces 

 me to pass over a multitude which might of themselves furnish 

 ample materials for the eulogy of any other man. Each of his 

 experiments henceforth became, whether in his own hands, or 

 in those of other philosophers^ fertile in luminous consequences ; 

 and there are still some in the number that have not received 

 sufficient attention, and which will perhaps one day become the 

 germ of quite a new order of important truths. 



His works were received with general interest : they were 

 translated into all languages ; the most illustrious natural philo- 

 sophers repeated his experiments, varied them, and commented 

 upon them. The Royal Society, on the appearance of his first 

 volume, decreed to him the Copley Medal, which is given for 

 the best work in natural philosophy, published in the course of 

 the year ; a medal of little value in itself, but which England 

 considers as the most noble prize that can be gained in science. 

 The Academy of Paris conferred on him an honour not less 

 noble, and still more difficult to be obtained, because rarer, 

 one of its eight places of foreign associates, for which all the 

 learned men of Europe strive, and of which the list, commen- 

 ycing with the names of Newton, Leibnitz, and Peter the Great, 

 has at no time degenerated from its first splendour. 



Priestley, loaded with honours, was, from his characteristic 

 inodesty, astonished at his good fortune, and at the multitude 

 of beautiful facts which nature seemed to have been unwilling 

 Xo reveal to any but himself. He forgot that her favours were 

 gratuitous, and that if she had been so successfully interpreted, 

 it was because he had discovered the method of constraining 

 her to divulge her secrets, by the indefatigable perseverance 

 with which he interrogated her, and by the innumerable inge- 

 nious contrivances to which i^e had recourse, to extort from her 

 the responses which he gave to the world. 



Others carefully conceal what they owe to chance ; Priestley 

 seems anxious to attribute to this all the facts he discovered. He 

 remarks, with a candour peculiar to himself, how many times he 



