C *& ] 



with the fame common and nitrous 

 air, the difference of the remit does 

 not amount to -^ of the bulk of 

 both airs. 



The different degrees of faljH 

 brity will be found in general to lie 

 between 103 and 109; at leaft, I 

 found it almoil always to be within 

 thefe two extremes: that is to lay, 

 that of the bulk of the two airs 

 the remaining column will be found 

 to occupy between 103 and 109 

 fubdivihons. The magnifier ap- 

 plied to the brafs tube (D, Fig. !,) 

 afhits greatly the accuracy of the 

 obfervation. 



This, iimple method eonftantly 

 ihewed me all the variations in the 

 conftitution of the atmofphere, in 

 regard to its fitnefs for refpiration, 

 which I could difcover by any other 

 method. 



A glafs 



