98 JOSEPH PRIESTLEY. [LECT. 



of his later years. At Nantwich, where he set up a 

 school, Priestley informs us that he bought an air 

 pump, an electrical machine, and other instruments, 

 in the use of which he instructed his scholars. But 

 he does not seem to have devoted himself seriously to 

 physical science until 1766, when he had the great 

 good fortune to meet Benjamin Franklin, whose 

 friendship he ever afterwards enjoyed. Encouraged 

 by Franklin, he wrote a " History of Electricity," 

 which was published in 1767, and appears to have 

 met with considerable success. 



In the same year, Priestley left Warrington to 

 become the minister of a congregation at Leeds ; 

 and, here, happening to live next door to a public 

 brewery, as he says, 



" I, at first, amused myself with making experiments on the 

 fixed air which I found ready-made in the process of fermenta- 

 tion. When I removed from that house I was under the necessity 

 of making fixed air for myself ; and one experiment leading to 

 another, as I have distinctly and faithfully noted in my various 

 publications on the subject, I by degrees contrived a convenient 

 apparatus for the purpose, but of the cheapest kind. 



"When I began these experiments I knew very little of 

 chemistry, and had, in a manner, no idea on the subject before I 

 attended a course of chemical lectures, delivered in the Academy 

 at Warrington, by Dr. Turner of Liverpool. But I have often 

 thought that, upon the whole, this circumstance was no dis- 

 advantage to me ; as, in this situation, I was led to devise an 

 apparatus and processes of my own, adapted to my peculiar 

 views ; whereas, if I had been previously accustomed to the 

 usual chemical processes, I should not have so easily thought of 

 any other, and without new modes of operation, I should hardly 

 have discovered anything materially new." l 



1 "Autobiography," 100, 101. 



