His difcovery of that peculiar 

 quality which nitrous air pofTefTes, of 

 deftroying or being deftroyed by 

 common air in proportion to its pu- 

 rity, is one of thole inventions 

 whofe utility will be more and more 

 confpicuous, when it ihall have un- 

 dergone all the improvements of 

 which it is fufceptible. Let it be 

 mentioned to his honour, that his 

 candour and modefty have made 

 him under-rate the value of this 

 ufeful production of his mquiriesj 

 when he fays, in his lait work, in- 

 titled, Experiments and Obfervations 

 relating to various Branches of Na- 

 tural PhiloJopby> with a Continuation 

 of the Obfervations of Air^ p. 269^ 

 " When I firft difcovered the pro- 

 u perty of nitrous air as a tell of 

 " the wholefomenefs of common 

 u air 3 1 flattered myfelf that it might 



, " be 



