P HI L 
I C A L 
T R A N S A 
OF THE 
O Y A L 
XZi 
O F 
VOL. LXXXI. For the Year 1791. 
PART II. 
Uaszrt Jc . 
LONDON, 
SOLD BY PETER ELMSLY, 
PRINTER TO THE ROYAL SOCIETY. 
MDCCXCI. 
