Of Vegetation. 319 



which is fuperior to vaft comprefling forces ; 

 and it is by the infinite combinations, aftion 

 and re-a&ion of thcfe principles, that all 

 the operations in animal and vegetable 

 bodies are effe&ed. 



Thefe aftive aereal particles are very fer- 

 viceable in carrying on the work of vegeta- 

 tion to its perfection and maturity. Not 

 only in helping by their clafticity to diftend 

 each du&ile part, but alfo by enlivening and 

 invigorating their fap, where mixing with 

 the other mutually attracting principles they 

 are by gentle heat and motion fet at liberty 

 to affimilate into the nourifhment of the re- 

 fpeftive parts : u The foft and moift nourifh* 

 <c ment eafily changing its texture by gentle 

 " heat and motion, which congregates 

 " homogeneal bodies, and feparates hete- 

 *' rogeneal ones/ 3 Newton's Opticks, qu. 

 31. The fum of the attracting power of thefe 

 mutually aCting and re-aCting principles 

 being, while in this nutritive ftate, fuperior 

 to the fum of their repelling power, where- 

 by the work of nutrition is gradually advanc- 

 ed by the nearer and nearer union of thefe 

 principles, from a leffer to a greater degree 

 of confiftency> till they are advanced to that 



vifcid 



