PHILOSOPHICAL 
TRANSACTION S 
OP THE 
EOYAL SOCIETY 
OF 
LONDON. 
(B.) 
FOR THE YEAR MDCCCLXXXIX. 
VOL. 180. 
LONDON: 
PRINTED BY HARRISON AND SONS, ST. MARTIN’s LANE, W.C., 
printers ht Orbxnarg to Utr ^ajcstg. 
MDCCCXC, 
