90 Mayow 



now entangled in terrestrial particles but free from 

 every kind of impediment, will continue to eternity 

 their motions, once started, without the aid of sul- 

 phureous particles ; since, indeed, inanimate things 

 will never suspend their movements unless they are 

 hindered by some cause^ Further, we must suppose 

 that nitro-aerial and sulphureous particles never 

 remain long in the same place, since they mutually 

 ward off and repel each other in consequence of a 

 natural antagonism ; and hence it is that there must 

 be a continual supply of nitro-aerial and of sulphureous 

 particles for producing sublunary fire. Yet since the 

 solar light has lasted for so many ages, it is probable 

 that nitro-aerial particles, free from the presence of 

 sulphureous particles, move with the greatest velocity 

 in it. The rays of light will be considered later. 



As nitro-aerial particles agitated with swiftest motion 

 constitute the solar body and fiery chaos, so probably 

 those pretty near the sun move with their velocity 

 somewhat abated and are intensely hot without burn- 

 ing. But at a greater distance from the sun ; namely, 

 in that region of the air which is commonly called 

 mid-air and is near the poles of the world, it is probable 

 that they cease altogether from their whirling move- 

 ment and are either altogether at rest or advance 

 pointwise, erect like spears, and that in this state 

 they constitute that other element of cold. For it 

 appears to me that we must certainly maintain that 

 cold is something positive and does not consist in this 

 merely that the particles of bodies cease from all 

 motion, as some have imagined ; for the effects of 

 cold are of such a kind as cannot result from mere 

 privation of motion, as we have shown above. Moreover,, 

 that nitro-aerial particles are lodged in ample enough 

 plenty in mid-air is evident from the fact that that 



