[ m 1 



of falubrity, or fitnefs for refpira- 

 tion, when I was with him at Paris 

 in the beginning of the fummer of 

 1777, and as I have, fince he re- 

 joined me in London, 1778, feen a 

 very great number of the like ex- 

 periments, I provided myfelf with 

 the fame inftruments, on purpofe to 

 imitate his method of examining 

 air, which I found fo accurate, that, 

 in ten experiments made one after 

 the other with the fame kind of 

 air, the refalt differed feldom above 

 j|^ ; that is to fay, that the remain- 

 ing bulk of the three meafures of 

 nitrous air, which he joins one after 

 another to the two meafures of atmo- 

 fpheric air, is fo alike in the various 

 experiments made with the fame 

 common air, that the difference will 

 feldom amount to more than -^ of 

 the whole ; which accuracy in ex- 

 L 4 ploring 



