Observations touching the principles of natural motions, and especially touching rarefaction & condensation together with a reply to certain remarks touching the gravitation of fluids / by the author of Difficiles nugae.

REMARK XXVIII, XXIX, XXX, XXXI.

TOuching the various position of the Mercury upon the top and bottom of a Hill, I need not say more than what is said in my 14^th Chapter of the Nugae, and therefore I spare repetition. Touching the rea∣son assigned by the Remark of the swel∣ling of a Bladder, and the raising of Bubbles out of Water and Spirit of Wine in the Air-pump, by me attri∣buted to Tension and Attraction, thereby wrought; but by the Remar∣ker to a tumultuary agitation of the parts of Water, &c. As he is little sa∣tisfied with my explication, so I am as little satisfied with his; both indeed produce an agitation of the Water in the Glass; but that which I assign, is regular, orderly and sutable to the effect produced; but the tumultuary

agitation of the Remarker, is confused, irregular, and unproductive of such regular motion; and besides, is un∣evident, and contradicted by Phaenome∣na of like nature; as we shall see plainly in the Magdeburgh Hemi∣spheres.

The Ludicrous Instance, as I call it, of the Attraction of Tobacco through Water, is properly brought in by me in this place, to shew that in many Instances, Attraction may be made through Water, which was seasonable in that place, and proper enough.