theſe Laws, all theſe Relations are indeed obſerv'd by the Planets with the utmoſt Exactneſs; therefore the Power of Attraction cauſes all the Planets to gravitate towards the Sun, in like Manner as the Moon gravitates towards our Globe.
Finally, as in all Bodies, Re-action is equal to Action, 'tis certain that the Earth gravitates alſo towards the Moon; and that the Sun gravitates towards both: That every one of the Satellites of Saturn gravitates towards the other four, and the other four towards it: All five towards Saturn, and Saturn towards all. That 'tis the ſame with regard to Jupiter; and that all theſe Globes are attracted by the Sun, which is reciprocally attracted by them.
This Power of Gravitation acts proportinably to the Quantity of Matter in Bodies, a Truth which Sir Iſaac has demonſtrated by Experiments. This new Diſcovery has been of uſe to ſhow, that the Sun (the Center of the planetary Syſtem) attracts them all in a direct Ratio of their Quantity of Matter combin'd with their nearneſs. From hence
