T O 
JAMES WEST, Efq; 
Treasurer and Vice-President 
OF THE 
ROYAL SOCIETY 
O F 
LONDON, 
FOR 
Improving Natural Knowledge, 
This Forty -third Volume of 
Philofophical Tranfaffiions 
Is humbly Dedicated \ by 
His Mojl Obedient y and 
Moft Humble Servant^ 
Cromwell Mortimer, R,S, Seer, 
Devonfliire-Street, near Queen’s Square, 
LONDON. 
November ioth, 1746. 
