See "Flying" and "scales" for further theories on the causes and effects of flame-throwing lizards.

Now we may be used to the idea, but stop and think for a minute if you haven't already. Obviously, it might be a bit surprising if you go to a zoo and see snakes belching flames at your face...I think. Don't you think it would be weird? In any case, I'm going to see if I can provide a reasonable explanation. This is the theory of mine that I am most comfortable with, just because it's the first that came to mind when I started thinking about dragons.

Anyways, my theory for fire is that there is a second pair of lungs in every dragon that stores a very light gas, far lighter than air. This second lung sack connects to the throat on the opposite side of the larynx and closer to the top of the dragon's body. Throughout the day the dragon continues to breathe: opening the passage of the throat to the larynx and closing it with each breath.

When a dragon uses its fire, it opens both the larynx and the entrance to the second pair of lungs, forcing both gases into the throat. As I've said in the second book, this process includes a bit of magic. For a split second as the atoms of these two gases collide, the strange gas gets a bit warmer, thus allowing very young dragons to produce smoke but not flame. The magic side of it is that the dragon uses its magical abilities to make the gas denser and much more concentrated in a short amount of time. If timed perfectly, the combination of extreme pressure inside the flame-resistant throat (with a closed mouth and nasal passage) and heat of natural fusion in the atoms, forces the atoms to chemically combine in an explosive manner. In milliseconds there is such a massive buildup of pressurized smoke that the combined gas is released, and from there combines naturally with the air to produce fire. In this way, as the gas moves along through the sky, more and more oxygen catches fire rapidly and can keep going for a very long range.

Now let's look at the implications of a highly developed science lab inside these creatures. Not only is that crazy to think about, but it adds a whole new element to the periodic table of elements that only dragons can make. But let's ignore this for a moment. Assuming this new gas can combine with air to produce flame, and since water is made out of oxygen, and a flammable element known as hydrogen...what does it mean? The two combined gives us the cure to most fires and is a miracle when a forest or house is burning...but technically speaking, a dragon could in fact then breathe fire under water, crazy as it sounds. If the strange dragon-gas could effectively break apart the atoms in water, the resulting fire would be an extraordinary event to witness. The jet of flame, I believe, would resemble more of a puff as it courses through the water in a weird smoke-like way. Look at certain gas-fueled fires. In some cases, water only helps to spread the flame and worsen the situation. If dragons could produce gas-induced flame...the implications are astounding!

In conclusion, this is my theory of how dragons breathe fire, and I even believe that they would be able to produce flames, perhaps even more effectively, underwater. And that's about it for fire-breathing. If there is anything I forgot to cover, or something that you wish I could answer, just leave me a comment below or PM me. And don't forget to ask for theories about other parts of the series and dragons themselves.