41 () LAWS OF MOTION. 



ascertain the degree of ice, and of cold, which 

 existed in Saturn ; of fire and of warmth in* 

 Venus: and if fire itself, instead of being a 

 body, the most repulsive, that exists throughout 

 the whole system of nature, were what it is 

 not ; if fire were an attracting body, it mighty 

 in that case, be assumed, that the sun consti- 

 tuted the attracting centre of the whole plane- 

 tary system. If the supposition could be ad- 

 mitted, which the testimony of all men, of com- 

 mon sense, in all ages, have absolutely de- 

 nied ; if it were admitted as a truth, that giants 

 and pigmies had an actual existence, all the 

 fictions recorded by that most ingenious man, 

 DEAN SWIFT, in the celebrated history which 

 he has given of those renowned kingdoms, 

 Brobdignag and Lilliput, must be admitted as 

 incontrovertible truths ; all the phenomena 

 which took place, may be legitimately deduced 

 from the principles assumed. So it is, in fact, 

 with the Newtonian philosophy. If the defi- 

 nitions, and the laws, contained in thePrincipia, 

 are once admitted as axioms, or self-evident 

 truths, which proclaim the attributes which be- 

 long to the different species of simple, and of 

 compound matter ; the whole chain of events 

 which take place throughout the whole system 

 of nature, may be satisfactorily explained. 

 The relative distances in which the different 

 planets are situated, as well as the velocity of 



