The principles of natural philosophy: with some remarks upon the fundamental principles of the Newtonian philosophy. In a introductory letter to Sir Hildebrand Jacob, Bart.

Date:
1754
Catalogue details

Licence: Public Domain Mark

Credit: The principles of natural philosophy: with some remarks upon the fundamental principles of the Newtonian philosophy. In a introductory letter to Sir Hildebrand Jacob, Bart. Source: Wellcome Collection.

    10/76 (page 8)
    t point ; Is there a vacuum, or not ? Let them either produce their proof of it 5 or difprove the arguments we (hall bring for a plenum. A vacuum is the poflulatum which fupports their whole fabric. Sir Isaac Newton has no where proved it 5 yet it is evident, the three properties of matter, which are the Axioms or evident principles, in all his reafonings upon motion, cannot be granted, unlefs a vacuum is firft afcertained. His firft Axiom is, That all bodies, once put in motion, have as conflant a tendency to move, as they have to reft before motion is imprefled on them. It is true, this law needs no proof but experience of the fad:. But where made Sir Isaac the experiment ? Not on this globe; becaufe the furface of it is fo involved in air and light, that it was absolutely impofli- ble for him to try a projedion in vacuo. Not among the planets, nor in the fpaces between them ; for he was never there, at leaft not be¬ fore he compiled his fyftem of philofophy. Befides we are pretty fenfihly informed, that there is a continuation of luminous matter between us and all the orbs. But all the phi- lofophers of that clafs hold that fluid to be fo rare.