518 ON GENERATION. 



are elements. It is, however, an argument of no great cogency 

 to say that natural bodies are primarily produced or com- 

 posed of those things into which they are ultimately resolved ; 

 for upon this principle some things would come out composed 

 of glass, ashes, and smoke, into which we see them finally 

 reduced by fire ; and as artificial distillation clearly shows that 

 a great variety of vapours and waters of different species can 

 be drawn from so many different bodies, the number of ele- 

 ments would have to be increased to infinity. Nor has any 

 one among the philosophers said that the bodies which, dis- 

 solved by art, are held pure and indivisible in their species, 

 are elements of greater simplicity than the air, water, and 

 earth, which we perceive by our senses, which we are familiar 

 with through our eyes. 



Nor, to conclude, do we see aught in the shape of miscible 

 matter naturally engendered from fire ; and it is perhaps im- 

 possible that it should be so, since fire, like that which is alive, 

 is in a perpetual state of fluxion, and seeks for food by which 

 it may be nourished and kept in being ; in conformity with 

 the words of Aristotle, 1 that "Fire is only nourished, and is 

 especially remarkable in this." But what is nourished cannot 

 itself be mingled with its nutriment. Whence it follows that 

 it is impossible fire should be miscible. For mixture, accord- 

 ing to Aristotle, is the union of altered miscibles, in which 

 one thing is not transformed into another, but two things, 

 severally active and passive, into a third thing. Generation, 

 however, especially generation by metamorphosis, is the distri- 

 bution of one similar thing having undergone change into 

 several others. Nor are mixed similar bodies said to be gene- 

 rated from the elements, but to be constituted by them in 

 some certain way, solvent forces residing in them at the same 

 time. 



These considerations, however, properly belong to the sec- 

 tion of Physiology, which treats of the elements and tempera- 

 ments, where it will be our business to speak of them more 

 at large. 



1 De Gen. et Corrup. lib. ii, cap. 50. 



