PHILOSOPHICA L 
TRANSACTIONS, 
OF THE 
ROYAL SOCIETY 
O F 
LONDON. 
VOL. LXXIII. For the Year 1783. 
PAR T I. 
LONDON, 
SOLD BY LOCKYETt DAVIS, AND PETER FLMSLY, 
PRINTERS TO THE ROYAL SOCIETY. 
MDCCLXXXIII. 
