to 6 | Galen oe oe —S— + 
‘ieee : 
PHYSICAL ann LITERARY. 31 
From what is faid, it will be eafy to ad- ‘ 
juft the proportion betwixt the ws motrix, 
and the refiftance of a body at reft. For 
tho’ refiftance and impetus are fo eflentially 
. different, as not to admit of a comparifon be- 
twixt themfelves; yet, the effects produced 
by them, are capable of a comparifon. Now, 
the force loft by the impingeing body is a juft 
meafure of the refiftance of the body at reft; 
and if the momentum, before and after im- 
pulfe, continue the fame; it muft follow, 
that the momentum of the body which is put 
in motion, is equal to the momentum \oft by 
the impingeing body. Therefore the momen- 
tum of the impingeing body, is to the refift- 
ance of the body at reft, asthe quantity of 
“matter of both bodies, is to the quantity of 
matter in the latter. | 
TH 1s power of refiftance in matter, which 
is never exerted but when an impulfe is made 
upon it, is of fo fingular a nature, as to lead 
‘us to fufpect fome very artful contrivance. 
It is furprifing that writers have given very 
little attention to the laws of motion, con- 
fidered in the light of final caufes, tho’ it is 
_ amoft beautiful fpeculation. It would car- © 
ry me too far from my prefent purpofe, to en- 
ter 
