PHYSICAL ann LITERARY. 111 
ver happens in any cafe. We fee for certain, 
many motions begun by animated beings; 
_we obferve many bodies moved by the im- 
pulfe of other bodies; and the mechanical 
caufes of fome motions, have through time 
been difcovered, which were not formerly 
perceived. Once in a day, it was found phi- 
lofophy to maintain that fmoak and vapour 
‘mounted upwards of themfelves by a princi- 
ple of levity, tho’ now one might as well af- 
fert that cork rifes up of itfelf in water. Ma- 
ny phenomena were explained from an ab- 
horrence of a void, which was fully as rea- 
fonable a paffion in a dead body, as the love 
of acenter, or an inclination to meet with o- 
ther bodies. The rife of water in pumps was 
4 afcribed to a felf-moving power in the water, 
and the pulfation of the arteries to a power 
Hy they had of dilating themfelves. ‘The power 
‘of magnetifm bears fome refemblance to that 
Y of gravity; the theory of it 1s ftill imper- 
- feét: yet there are a multitude of facts which 
i indicate a mechanifm by means of fome ef- 
F fluvia ; particularly the new method of ma- 
king artificial magnets by attrition, and the 
rod is prefented toa son Ad needle, the 
fame 
