E I2 5 ] 

 in our element : and, indeed, I was 

 much of that opinion, till Abbe 

 Fontana convinced me of my error J 

 for, by keeping a bottle full of air 

 taken from the atmofphere at the 

 fame time, the conftitution of it is 

 explored and accurately regiftered % 

 and examining fome time afterwards 

 this very air, clofely ilmt up in a 

 bottle, you find the refult of the 

 trial to correfpond exactly with the 

 remit of that which was made at 

 the time when the air was taken 

 from the atmofphere, and by no 

 means conform with the refult of 

 the trial inftituted with the com- 

 mon air of the day, unlefs it fliould 

 happen that the conftitution of the 

 atmofphere was jure, the fame at 

 both times. I take this to be a 

 demonftrative proof of the excel- 

 lence of this method, as well as of 



the 



