Scholium.
The refiiiattce of ſphærical bodies in fluids ariſes partly from the tenacity, 'partly from the attrition, and partly from the denſity o the medium. And that part: of the reſiſtance, which ariſes from the denſity of the fluid, is, as I (aid, in a duplicate ratio of the velocity, the other part, which ariſes from the, tenacity of the fluid, is uniform, or as the moment of the time: and therefore we might now proceed to the motion of bodies, which are refifted partly by an uniform force, or in the ratio of the moments of the time, and partly in the duplicate ratio of the velocity. But it is fuiiicienl: to have cleared the way to this ſpeculation in the 8th and 9th Prop. foregoing, and their Corollaries. For in thoſe Propoſitions, iniiead of the uniform reſiſtance made to an aſcending body ariſing from its gravity, one may fubfiitute the uniform reſiſtance which ariſes from the tenacity of the medium, when the body moves by its"z/is infra alone; and when the body aſcends in a right line, add this uniform reſiſtance to the force of gravity, and ſubduct it when the body deſcends in a right line. One might alſo go on to the motion of bodies which are refified in part uniformly, in part in the ratio of the velocity, and in part in the duplicate ratio of the ſame velocity. And I have openeda way to this in the 13th and 14th Prop. foregoing, in which the uniform reſiſtance ariſing from the tenacit of the medium, may be fubfiituted for the force ofygravity, or be compounded with it as before. But I. hafien to other things.,
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