[CHAP. VII. Of the Productions of Elemental Fire.]
It is to be observed, That Points of Fire are more numerous, and more suddenly propagating, than any other Element, or any other Creature that is subject to Human Perception. But, Sparks of Fire, resemble the Seeds of Vegetables, in this, That as Vegetables will not encrease in all sorts of Soyles, alike; neither will the Points of Fire, in all sorts of Fuel, alike. And, as Vegetables produce different Effects in several Soyls; so doth Fire on several Fuels: As for example, The Seeds of Vegetables do not work the same Effect in a Birds Crop, as in the Earth: for, there they encrease the Bird by digestion; but, in the ground, they encrease their own Issue (as I may say): So Fire, in some Fuels, doth destroy it self, and occasions the Fuel to be more consumed; when as, in other sorts of Fuel, Fire encreases extreamly. But Fire, as all other Creatures, cannot subsist single of it self, but must have Food and Respiration; which proves, Fire is not an Immaterial Motion. Also, Fire hath Enemies, as well as Friends; and some are deadly, namely, Water, or Watry Liquors. Also, Fire is forced to comply with the Figurative Motions of those Creatures it is joyned to: for, all Fuels will not burn, or alter, alike.
[CHAP. VIII. Of FLAME.]
Flame is the Rarest Part of Fire: and though the Fuel of Flame be of a vaporous and smoaky Substance; yet surely, there are pure Flames, which are perfect Fires: and, for proof, we may observe, That Flame will dilate and run, as it were, to catch Smoak: but, when the Smoak is above the Flame, if it be higher than the Flame can extend, it contracts back to the Fiery Body. But, Flame doth somewhat resemble that we name Natural Light: but yet, in my opinion, Light is not Flame; nor hath it any Fiery Property, although it be such a sort of Extenuating or Dilating Actions, as Flame hath.
[CHAP. IX. Of the two sorts of Fire most different.]
There are many sorts of Fires: but two sorts are most opposite; that is, the Hot, Glowing, Burning, Bright, Shining Fire; and that sort of Fire we name a Dead, Dull Fire; as, Vitriol Fires, Cordial Fires, Corrosive Fires, Feverish Fires, and numerous other sorts; and every several sort, hath some several Property: as for example, There is greater difference between the Fiery Property of Oyl, and
the Fiery Property of Vitriol: for, Oyl is neither Exteriorly Hot, nor Burning; whereas Vitriol is Exteriorly Burning, though not Exteriorly Hot: but, the difference of these sorts of Fires, is, That the Actions of Elemental Fire, are to ascend, rather than to descend: and the Dull, Dead Fire, is rather apt to descend, than ascend; that is, to pierce, or dilate, either upwards, or downwards: but, they are both of Dilating and Dividing Natures. But this is to be noted, That all sorts of Heats, or Hotness, are not Fire. Also it is to be noted, That all Fires are not Shining.