Page:The Mathematical Principles of Natural Philosophy - 1729 - Volume 1.djvu/41

Rh parts of the body be equal to the impreion of the fore parts of the body on the fluid, that is unles the relative velocity with which the fluid puhes the body behind is equal to the velocity with which the body puhes the fluid; that is, unles the abolute velocity of the recurring fluid be twice as great as the abolute velocity with which the fluid is driven forwards by the body; which is impoible. Therefore the reitance of fluids ariing from their vis inertia can by no means be taken away. So that we mut conclude that the celetial fluid has no vis inertia, becaue it has no reiting force; that it has no force to communicate motion with, becaue it has no vis inertia; that it has no force to produce any change in one or more bodies, becaue it has no force wherewith to communicate motion; that it has no manner of efficacy, becaue it has no faculty wherewith to produce any change of any kind. Therefore certainly this hypotheis may be jutly called ridiculous, and unworthy a philoopher; ince it is altogether without foundation, and does not in the leat erve to explain the nature of things. Thoe who would have the Heavens filled with a fluid matter, but uppoe it void of any vis inertia; do indeed in words deny a vacuum, but allow it in fact. For, ince a fluid matter of that kind can no ways be ditinguihed from empty pace; the dipute is now about the names, and not the natures of things. If any are o fond of matter, that they will by no means admit of a pace void of body; let us conider, where they mut come at lat.

For either they will ay, that this contitution of a world every where full, was made o by the will of to this end, that the operations of