PH I LO SO PH I CAL 
r R A N S A C T I 0 N 
OF THE 
ROYA L S O C I E T Y 
OF 
LONDON. 
FOR THE YEAR MDCCCLXXH. 
VOL. 162 .— PART I. 
LONDON: 
PRINTED BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET. 
MDCCCLXXH. 
