from G to I, is continually protruded or attracted to the Sun, or at least is brought nearer to it fo that AF and GI, being the Lengths which the faid Planet is to run at each Place in the following Minute, in the Tangent Lines AP and GQ, it is forced to forfake them, and, in the very fame Inftant, to approach so much nearer to the Sun, as the Lines F G and IH are in Length; without which it would not be poffible that this Planet could continue in its Curve Way A EDC about the Sun ? This is not to be anfwer'd by the Hypothefis which fome Philofophers have hitherto maintain'd, That the Sun has a Vortex of a fubtile Matter about it, which running round, drags the Bodies of these Planets along its Stream; forafmuch as the Gravity thereof remains the fame; therefore they are bound to fhew why that Matter itself defcribes a Curve Line, and does not, like other Things, move directly, according to Tangents; fo that here likewife we must have recourfe to a Power that governs the Motion of this Matter: But the famous Mathematician Sir Ifaac Newton, and others, have fhewn, that we feek in vain the Properties of this Circular Motion in the Matter of the Vortices. SECT. LXXIII. Thirdly, By the Courfe of the Planets in an Ellipfis. BUT to cut off all Cavilling about this Difference, it may be fufficiently proved from the Property of the Curve Line, according to which each of thefe Planets are moved, that there must be an inceffantly directing Power that regulates their Courses, and that they cannot alone be carried forwards by any circularly moving Matter. For |