The Nature of Fire

80. The nature of fire and its distinction from air

How can flame be ignited in these cavities? What is the nature of fire?

When the earth-aether particles are separated from one another, regardless of their size or shape, they are surrounded by the fire-aether and so must follow their course.

• This makes them take the form of fire just as they take on the form of air when floating among the air-aether globules, imitating their movement.

Therefore, the first and main difference between physical air and fire is that fire [earth-aether + fire-aether] particles move faster than air [earth-aether + air-aether] particles

• This is consistent with the fire-aether being much more agitated than air-aether.

The secondary difference is that:

• the largest particles of earth-aether can best preserve and nourish fire.
• the smallest particles of earth-aether can best retain the form of air.

Quicksilver particles are among the largest earth-aether particles.

• These can also receive the air-aether when they are very agitated by heat.
• But they lose it afterwards when this agitation diminishes.
• Their weight causes them to descend

81. How fire is first ignited

The air-aether globules occupy all the spaces:

• around the Earth
• in the Earth’s pores that are large enough to receive them

These globules are so crowded in the pores that they touch each other and support each other.

• If one moves, its neighbors also move unless that motion was a rotation

The fire-aether fills all the gaps left by these globules and moves very rapidly within them.

• But these still cannot carry the earth-aether particles with them because the earth-aether are surrounded by the air-aether

Consequently the fire-aether cannot give the form of fire to the earth-aether because the earth-aether:

• all support one another
• are supported by the air-aether around them

To generate fire, the air-aether globules must be expelled by force from the gaps between some earth-aether particles.

This will prevent the earth-aether from supporting each other.

• This will isolate each earth-aether particles so that they can be surrounded by the fire-aether
• This isolation with the fire-aether will make the earth-aether follow the course of the fire-aether in various directions.

82. How is Fire Sustained?

To sustain this fire, the earth-aether particles must be dense, solid, and apt for motion.

This will allow it to move and give it force as directed by the fire-aether to repel the air-aether which constantly pushes them to return to the place of the fire from which they were expelled.

• This prevents the fire from being extinguished by joining the others again.

83. Why Does Fire Need Nourishment?

Through the fire, the earth-aether goes into the air where they lose their agitation little by little.

• This makes them cease having the form of fire and turn to smoke.

This is why fire cannot remain long in the same place unless there is some body that it successively consumes to maintain itself.

Such a body should be:

• separable one after the other by the action of the fire which then changes them into smoke.
• plentiful and large enough to have the strength to repel the air-aether which tend to suffocate this fire
  • The earth-aether in the physical air is not enough for this.

84. How Is Fire Sparked from Flint?

Flints are hard, rigid, and friable.

Because of their hardness and rigidity, when struck by a hard body, the spaces between many of their particles, usually occupied by air-aether globules, become narrower.

These air-aether are compelled to spring out. They leave only the fire-aether around them.

Due to their friability, once these particles of flint are no longer pressed by the impact, they spring apart. The fire-aether, found solely around them, composes the fire.

• A is flint with visible air-aether globules in its anterior particles
• B is the same flint when struck by a hard body. Its channels have become narrower, leaving only the fire-aether.
• C shows the same flint already struck, with some particles separated and having only the fire-aether around them, resulting in sparks of fire.

85. How is Fire Produced from Dry Woods?

Wood will not emit sparks if struck because it is less hard.

The first part of it that encounters the striking body bends toward the second part. That second part then bends toward the third part.

Thus, the air-aether globules do not leave their intervals simultaneously.

Instead, they depart successively, sometimes from one, sometimes from another.

However, if the wood is rubbed vigorously for a long time, the friction causes unequal agitation and vibration of its particles. This can shake loose the air-aether globules, separating them from each other. This action then transforms them into fire.

86. How is Fire Produced from the Collection of Sunbeams?

Fire can also be ignited by directing many sunbeams through a concave mirror or convex glass onto a particular spot.

The action of these sunbeams has globules of the air-aether as their substrate. It is much more vigorous than the usual motion of these globules.

Since it originates from the fire-aether of the Sun, it has sufficient speed to ignite fire.

Additionally, so many rays can be focused at the same time that they have enough force to agitate terrestrial particles with the same speed.