Chapter VIII

_If they rise to the Hill-tops._ } Rain in a Day or two.

WHEN Mists are very, heavy in themselves, and rise only by the Action of that protrusive Force, exerted by the subterranean Fire, they can rise no higher than where the Gravitation becomes superior to that protrusive force, for then they descend again by their own Weight, and this occasions the Appearance mentioned in the Observation of their hanging upon Hill-tops, where they are very soon condensed, and fall down in Rain.

THERE was formerly a very idle and ill grounded Distinction between moist and dry Exhalations, whereas in Truth all Exhalations are moist, or in other Words are watery Steams thrown off by Bodies respectively dry, and the former Distinction was invented only to solve these Phænomena of which we have been speaking, that is, the Mist rising and, dispersing without Rain, and the Mist condensed and resolved into Rain, which as I have shewn may be much better explained without any such Distinction.