On Sal Nitrnm and Nitro- Aerial Spirit 123 



•whole blaze and kindle flame everywhere in their 

 passage. For since the sulphureous particles, which 

 burn at the top of a lamp, have proceeded from the 

 wick, they must necessarily have passed through the 

 whole of the intermediate flame. Further, it is not to 

 be doubted that these particles were burning from their 

 first entrance into the flame, since the lowest part of 

 the flame is produced only by the kindling of sul- 

 iphureous particles. And hence it is that when a lamp 

 goes out in consequence of a failure of sulphureous 

 nutriment, the flame is last seen at the top and at 

 •some distance from the wick. For it is the last group 

 of sulphureous particles passing through the blaze, and 

 -everywhere in its transit kindling flame, that is seen at 

 the top of the blaze. But since no sulphureous par- 

 ticles now remain to follow these last ones, there must 

 be an interval without flame between the last burning 

 particles at the top of the flarne and the wick. 



But now the question arises why the sulphureous 

 particles at a certain distance from the wick no longer 

 kindle flame. For since the sulphureous particles burn 

 at the extreme verge of the flame, they must conse- 

 quently be in more violent motion there than when, 

 as yet unkindled, they were about to enter the flame. 

 And therefore there seems to be more reason for these 

 particles, once kindled, persevering in their fiery 

 movement and flame, than for their entering upon a 

 fiery movement at first. As to this, my opinion is 

 that the fire is extinguished at a certain distance 

 from the wick, not because the motion of the sul- 

 phureous particles is diminished, but because, in their 

 passage through the flame, they are rubbed so much 

 and made so small and subtle by their own combus- 

 tion that they become at last incapable of throwing 

 nitro-aerial particles into fiery movement. In fact, 



