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increases likewise : but .how this motion, v 

 only generated by tlie former, should at last get the bet- 

 ter of the power that produces it, and. that too, ;*l tbr 

 very time this power has acquired its utmost force and 

 energy, seems somewhat difficult to conceive. It is the 

 only instance I know, wherein the effect increasing re- 

 gularly with the cause; at last, whilst the cause is still 

 acting with full vigour, the eiiect entirely gets the better 

 of the cause, and leaves it in the lurch. For the body 

 attracted, is at last carried away with infinite velocity 

 ffom the attracting body. By what powtr is it carried 

 away? 'Why, say our philosophers, by the very power 

 of this attraction, which has now produced a new power 

 superior to itself : to wit, the Centrifugal force. How- 

 ever, perhaps all this inay.be reconcileable to reason ; far 

 be it from me to presume to attack so glorious a system 

 as that of attraction. The law that the heavenly bodies 

 are said to observe, in describing equal areas in equal 

 times, is supposed to be demonstrated, and by this it 

 would uppear,' that the centripetal and centrifugal forces 

 alternately get the mastery of one another. 



However, I cannot help thinking it somewhat hard to 

 conceive, that gravity should always get the better of the 

 centrifugal force, at the very time that its action is the 

 smallest, when the comet is at the greatest distance from 

 the sun ; and that the centrifugal force should get the 

 better of gravity, at the very time that its action is the 

 greatest, when the comet is at its nearest point to the sun. 



To a common observer it would rather appear, that 

 the sun, like an electric body, after it had once charged 

 tlie objects that it attracted, with its own efrluvia or at- 

 mosphere, by degrees loses its attraction, and at last 

 even repels them, and that the attracting power, like 

 what we likewise observe in electricity ,> does not return 

 again till the effluvia imbibed from the attracting body 

 are dispelled or dissipated; when it is a^ain attracted 

 and soon alternately. For it appears (at least to an un 

 philosophical observer^ somewhat repugnant to reason 

 to &ay, that a body ih ing oft irom another body some 

 thousands of miles in a minute, should all the while be 



