[ l$z ] 



ploring the degree of goodnefs of 

 refpirable air furpaffes the exadlnefs 

 of judging of the degree of heat 

 and cold by the thermometer of 

 Reaumur. 



The Abbe has, fince I faw him 

 at Paris, changed fomewhat his in- 

 ftruments and method of filing 

 them, or rather corrected them a 

 little ; but they remain llill mate- 

 rially the fame as they were be? 

 fore. 



1 rauH: beg the reader to flop 

 here, and to carl his eyes upon the 

 copper plate and the explication of 

 the figures before he proceeds far- 

 ther. 



The new Eudiometer^ or ipflru- 

 ment for finding the accurate degree 

 of falubrity, or fitnefs for refpira- 

 tion of a given air, con fills of 

 different pieces ; two of \i hich are 



the 



