Chap.4 ■ PHILOSOPHY. 153

manner os wool compressed, and such like bodies, by whichthe parts of the fluid will be in some measure entangledtogether, and their motion be obstructed, the fluid willbe in a manner tenacious, and give a resistance upon that ac-count over and above what depends upon its elasticity on-ly a ; and the resistance derived from that cause is to bejudged of in the manner before set down.

I y. I t is now time to pass to the second part of this theo-ry ; which is to assign the measure of resistance, accordingto the proportion between the density of the body and thedensity os the fluid. What is here to be understood by theword density has been explained above b . For this purposeas our author before considered two distinct cases of bodiesmoving in mediums; one when they opposed themselves tothe fluid by their power of inactivity only, and anotherwhen by ascending or descending their weight was com-bined with that other power: so likewise, the fluids them-selves are to be regarded under a double capacity; eitheras having their parts at rest, and disposed freely without re-straint , or as being compressed together by their ownweight, or any other cause,

16. In the first cafe, if the parts of the fluid be whollydisingaged from one another, so that each particle is at liber-ty to move all ways without any impediment, it is shewn,that if a globe move in such a fluid, and the glebe and par-

a Vid. ibid.coro’l. 6 . J k In 5 2 .

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