PHILOSOPHICAL 
TRANSACTIONS, 
OF THE 
ROYAL SOCIETY 
OF 
LONDON. 
FOR THE YEAR MDCCCIX. 
PART II. 
LONDON, 
PRINTED BY W. BULMER AND CO. CLEVELAND-ROW, ST. JAMES’S; 
AND SOLD BY G. AND W. N1COL, PALL-MALL, BOOKSELLERS TO HIS MAJESTY t 
AND PRINTERS TO THE ROYAL SOCIETY. 
MDCCCIX 
