PHYSICAL eS ee 
. onitie wore s 
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Read before a Society in EDINBURGH, 
, bee i cs 
and publifbed by them. 
| in . ¥. 
[ FJ a a 
3 # 
EDINBURGH: 
rinted by G. HamitTon and J. Barrour, 
Printers to the he Univerfity. 
M,DCC,LIV. 
