[ 469 r 
Northern feas, and amid ft mountains of ice in the neigh- 
bonrhood of the Pole. 
Should you think thefe experiments and obfervations 
on heated air of fufficient importance to be communi- 
cated to the Royal Society, they are at your difpofal. 
I have the pleafure to find, that Dr. priestley is pro- 
fecuting his very ingenious inquiries on air. In a letter 
I lately jeceived from him, he informs me, that he has 
' difcovered a fpecies of air, which will preferve animal 
life fix times longer than atmofpheric air. 
Iremaiiij with great, efteem, &Ca., 
XLVI: 
