Cor. 2. If the more diſtrant part of this ſolid be rejected, becauſe its attraction compared with the attraction of the nearer part is inconſiderable; the attraction of that nearer part will, as the diſtance increaſes, decreaſe nearly in the ratio of the power
Cor. 3. And hence if an finite body, plane on one ſide, attract a corpuſcle ſituate over-againſt the middle of that plane, and the diſtance between the corpuſcle and the plane compared with the dimensions of the attracting body be extremely ſmall; and the attracting body conſiſt of homogeneous particles, whoſe attractive forces decreaſe in the ratio of any power of the diſtances greater than the quadruplicate; the attractive force of the whole body will decreaſe very nearly in the ratio of a power whoſe ſide is that very ſmall diſtance, and the index leſs by 3 than the index of the former power. This aſſertion does not hold good however of a body conſiſting of particles whoſe attractive forces decreaſe in the ratio of the triplicate power of the diſtances; becauſe in that caſes the attraction of the remoter part of the infinite body in the ſecond corollary is always infinitely greater than the attraction of the nearer part.
Scholium
If a body is attracted perpendicularly towards a given plane, and from the law of attraction given the motion of the body be required; the problem will be ſolved by ſeeking (by prop. 39.) the motion of the body deſcending in a right line towards that plane, and (by cor. 2. of the laws) compounding that motion with an uniform motion, performed in
