How did dragons breath fire?

[MythRat]

The sturdiest theory I've managed to come up with is the 'fire breath' being a form of venom. Hollow fangs similar to those spitting cobras have connected to a venom gland that produces something like a mildly diluted form of picric acid carried in a viscous mucus to keep it stable while still internal as well as giving it greater 'heft' so it's less likely to be thrown badly off aim by fickle wind directions.
Something I feel I should mention, though, just to make sure we're all on the same page, you don't generate wind speed by flying fast. The ambient wind speed stays the same, you're just moving fast enough through it to create lift. When firing a weapon you'd only have to correct for your rate of movement relevant to your target and the ambient wind speed. Saying you have greater than that to adjust for is kind of like assuming that a road moves under you when you drive on it instead of it staying in one place and you moving over it and judging on when to brake by how fast the *road* is moving.
Anyway, wind speed can work in your favour, too. If the wind is at your back, you'd actually have to shorten your aim because your weapon would be pushed further than normal, and obviously the revers is true if the wind is in front of you but when you can fly all you'd have to do would be circle around to find the most favourable wind direction. The only thing you'd be badly thrown off by would by the wind suddenly changing it's mind after you'd fired it and blowing the other way, hehe.

Anyway, enough rambling about wind speed. Sorry.

I say picric acid because it's fairly simple and would be easy to generate biologically. It's also unstable enough that it would explode on impacting a target if not ignite sooner by air friction (like a flamethrower with a widely spaced pilot light). Having two separate chemicals that mix is flashy and plausible enough for a movie but it would be extremely expensive, biologically speaking, and things generally evolve along the lines of 'least resistance' and 'best possible efficiency at the lowest biological cost'.
A digestive by-product gas, like methane, isn't terribly efficient because it means the dragon has NO weapon if he hasn't eaten within the last 12-15 hours. Being a large predator does not guarantee a consistent food supply in the amounts and frequency it would take to not only fuel a body that big and that active but also somehow store a by-product gas. In fact most times, the bigger a predator is, the less consistent its food supply and the more energy it has to spend on getting that food. A stored gas would leak, be reabsorbed, and/or degrade beyond use over a fairly short span of time. So if a dragon is using fire as a weapon/hunting tool, it has to use something that it can generate and store reliably over long periods of time (as in weeks if not months) despite unexpected changes in outside variables (like a gap in one's food supply). Gas does not fulfill those specifications. A flammable or acidic venom would do so nicely, though.
Venom can be produced and maintained with or without food (so long as the animal has at least some reserves and most do unless they're halfway to dead anyway), used at a consistent strength reliably, and replenished very quickly.
Now, picric acid is unstable and has a tendency to saturate and become more unstable the longer it sits, so (when unused for a while) the dragon would have to allow small amounts of the old venom out either at specific times or possibly a constant slow trickle. Either way, it's going to need a thick protective mucus in it's mouth and throat to avoid being damaged by the overflow (believe or not this actually supports the venom idea if you go along with general dragon mythology). Thick mucus+unstable venom = REALLY horrible breath, one of the things dragons are fairly famous for across multiple cultures and mythologies.
So the whole thing fits nicely, really. (I've spent about three years just on this one part of my theory and it's pretty solid by now, but I'm always open to critique and counter-discussion so feel free to poke at any holes you think you see in it. I'm more interested in having a solid, well-rounded hypothesis than I am in 'being right').
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"Humans are so interesting. Do you know, in a universe full of wonders, they've managed to invent boredom?" - Death

[Jewleyedraco]

Dragons have a sack filled with a flammable liquid that when hits the air it cumbusts into a fire that shoots out of there mouts. And in there mouths are a little hole that let's them breath that fier
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With a fiery breath, skin harder then dimand, strength mightier then eny other creatur. Dragons are the ultimate being

[Namhias]

A possible explanation, yes. Though to say that every dragon has that is a bit... much. I don't have that for example.

[Shaprite]

I was told that its like a sigh with a force behind it.
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Beware. I bite!

[Jasriella]

[Ranna]

Has anyone else seen 'dragons, a fantasy made real'?
I found the dvd cheap and got it. It was a documentary pretending that a frozen dragon carcass had been found inside a mountain cave.

The program came up with an interesting idea on how it could have been possible:


Bacteria in the gut breaking down foodstuffs to release hydrogen, which gets stored in 2 'gas bladders'.

Hydrogen makes the dragon lighter, making flight more possible.

Dragon scraping metal from ores creating the ignition source (somehow)

Flap at back of throat (like a crocodile has) to prevent fire going down throat

Tough mouth interior to resist extreme heat.

Not sure if this was everything, I would recommend that you watch it if you get the chance. They also had a dragon species 'evolution' to account for wyverns, water dragons, and eastern too. Some bits were off, but it was amusing and thought provoking.
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Ranna, the first, the smallest bell. Ranna the sleepbringer, the sweet, low sound that brings silence in its wake.

[Obsidian]

Fire breath... ergh, yeah, in theory. I know I never had it, but a really nasty set of bacteria in the saliva is just as effective at taking down large prey.
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Prey, tell...

[Jaden]

Thread Bump.

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