[ *76 ] 



SECTION XX. 



Experiments tending to invefiigatt 

 the moji accurate and expeditious. 

 way of putting common air to the 

 tej}, on purpofe to judge of the fa- 

 lubrity of any country. 



I HAVE already faid enough 3 in 

 the introduction to the fecond pari 

 of this work, of the accuracy with 

 which this difficult and important 

 inveftigation may be made by em- 

 ploying the inltruments of Abbe 

 Font ana ; but as there is much more 

 attention and dexterity required to 

 judge with the greatefl nicety of 

 the degree of falubrity of the at- 

 mofpheric air than of any other? 

 as the other airs are of much lefs 



importance 



