PHENOMENA OF THE UNIVERSE. 127 



nature is more certain than that twofold one, that out of 

 nothing nothing comes, and that there is not anything which 

 can be reduced to nothing, but that the quantum itself of 

 nature, or the universal sum of matter, is ever the same, 

 admitting neither of increase nor of diminution ; so it is not 

 less certain, although it has not been so clearly remarked or 

 asserted (whatever men may pretend respecting the power 

 of matter being equally proportioned to its forms), that out 

 of that quantum of matter more or less is contained under 

 the same dimensions of space, according to the difference of 

 the bodies by which they are occupied, of which some are 

 very evidently found to be more compact, others more ex 

 tended or diffused. For a vessel or a cavity filled with 

 water and air cannot receive the same portion of matter, 

 but the one more and the other less. If, therefore, any one 

 were to assert that from an equal quantity of air an equal 

 quantity of water could be produced, it would be the same 

 with asserting that something could be produced out of 

 nothing. For that must, of course, be supplied out of no 

 thing which is supposed to be wanting in matter. Again, 

 if it were asserted that an equal quantity of water could be 

 turned into the same quantity of air, it would be the same 

 with asserting that something could be reduced to nothing. 

 For the superfluous matter must, of course, have vanished 

 into nothing. And I do not doubt that this will admit of 

 calculation imperceptible in some respects, but definite and 

 certain, and known to nature. As, if one were to say, that 

 a body of gold compared with a body of spirit of wine were 

 a collection of matter exceeding in a ratio of twenty to one, 

 or thereabout, he would speak the truth. In setting forth, 

 therefore, that history which I have spoken of, respecting 

 the quantity and paucity of matter, and the union and ex 

 pansion of matter, from which those notions of density 

 and rarity (if rightly considered) have their rise, I shall 

 preserve this order; in the first place, to give an account of 

 the relative proportions of different bodies (as of gold, 

 water, oil, fire), and having examined the ratios of different 

 bodies, I will afterwards treat of the retirings and excursions 

 of the same body, with calculations or proportions. For 

 the same body, without accession or subtraction, or with 

 the smallest possible degree of either, from various impulses 

 both external and internal is able to gather itself into a 

 greater and lesser sphere. For sometimes the body endea 

 vours to return to its former sphere, and sometimes evidently 

 exceeds it. In the first place then, I will enumerate the 

 courses, differences, and proportions of any natural body 



