The original question was:
I can’t get my head round how dragons could emit flame. It must have been more than thermal regulation, because enzymic processes are already impossible at well below 100degC. If it was something combustible in the breath (e.g., phosphine), then oxygen must have been almost entirely missing from the breath, otherwise the animal’s organs would be burned by combustion on the way out. If combustion was photo-initiated what was the mechanism? Do you have a mechanism that makes sense?

Answer by John Mackay and Diane Eager

Flammable breath is much more common than people think. It is well known that in the gut, both anaerobic metabolism and bacterial action can produce methane, hydrogen sulphide, hydrogen and other flammable gases. As long as these are not ignited until they leave the body they are not dangerous – mostly they just smell horrible.

The biggest gas producers of all are the ruminants, who are being bullied by the climate change lobby due to the large volume of methane they belch out the front end. The gases produced in ruminants’ stomachs are flammable, and there are stories of fires caused when a serious build-up of these gases in the cow or sheep which has been eating too much fresh clover has had to be released by a sharp hollow tube which was punched into the stomach by a farmer who forgot to put out his cigarette. The sudden release of the methane produced spectacular explosion which damaged the farmer more than the sheep.

So for fire breathing dragons, aka dinosaurs, let us start by suggesting that the methane generated by eating green plants (since all creatures were originally vegetarian) was suddenly expelled across an organo-electric source, generated by a sophisticated nervous system (as in the electric eel) and probably situated on or near the mouth or gas releasing orifice or even a safe distance from the orifice such as in the hanging light apparatus used by the angler fish. Since we can connect the electric eel up to run a light bulb I am sure God was clever enough to use it to generate sparks. Remember the old circus trick of the human fire breathers? They never got a burnt mouth since the liquid they spewed out was not combusted until it got outside their mouth where air could mix in and a flame could ignite. As to what the creature could use it for – that’s another question?

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About The Contributor

Diane Eager