Why Some Things Burn and Others Do Not

102. Why does the flame of wine spirit not burn linen?

This is because the particles of wine spirit is too thin.

• It does not have enough ratio to preserve fire.

For example, if the spirit of wine ignites a linen cloth, this very fine flame will consume all the spirit of wine.

• But it will not touch the linen because its particles are not thin enough to be moved by it.

103. Why wine spirit ignites very easily.

The spirit of wine easily feeds the flame because it consists only of very thin particles.

• It also has some branches so short and flexible that they do not adhere to each other.

In that case, the spirit would turn into oil.

However, they are arranged in such a way that they leave many extremely small spaces around them.

• These spaces can only be be occupied by the fire-aether, not by the air-aether globules.

104. Why water is difficult.

On the other hand, water seems very adverse to fire because its particles are:

• thicker, smoother, and glossier.
  • This allows the air-aether globules to surround and following it everywhere.
• flexible
  • This lets it easily enter the channels of burning bodies and repel the particles of fire and prevent others from igniting.

105. Why is the force of large fires increased by water or salts thrown in?

However, water thrown into some burning bodies help the fire in large flames.

This is because the water helps the earth-aether particles to bounce back with force and ignite themselves.

Hence, even a small amount of water thrown into large flames increases the fire.

Salts are more effective than water in increasing fire.

• Their particles are rigid and oblong.
• They vibrate like spicules in the flame.
• They have great force to shake their minutiae by striking other bodies.

Therefore, they are usually added to melt metals.

106. What kind of bodies easily burn?

Things commonly used for feeding fire, such as wood and the like, consist of various particles.

• Some of these are very fine.
• Others are thicker.

Most of them are branched with many branches interlacing them.

These branches allow the particles of fire to enter these channels and quickly move the finest particles first, and then the moderate ones.

• With the help of both, they move the thicker ones.

Thus, they swiftly shake off the air-aether globules:

• first from narrower gaps
• then from the remaining ones.

They carry all of the air-aether away except for the thickest ones, which turn to ashes.

107. Why some things ignite, and others do not.

When such particles exit from the burning body so numerously that they have the power to expel the air-aether globules from some adjacent space, they fill that space with flame.

If they are fewer, a flame without smoke is produced.

• This flame may gradually creep through the meatus of its funnel, finding material to consume.

This is observed in those cords or wicks used in war for igniting gunpowder.

108. Why does fire last a while in embers?

If the fire has no branched material around it, then it is not preserved.

It is only preserved because the pores of its material body need some time to dissolve all its earth-aether particles so that the fire-aether can free itself.

Coals, covered with ashes, retain fire for many hours solely because its fire is inherent in very thin and branched [earth-aeter] particles.

Those particles move very quickly. But they can only be subdivided and separated one after another.