[alchemyromcom]

>Carbon in our souls

I think it might be an allusion to alchemy. Basically, the alchemists believed that ash (what was left after burning something) was the soul of all things...And-- this is where my complete lack of understanding about science shows-- I'm pretty sure Ash has lots of carbon? It's, you know, poetic. Many have claimed that poems are the "language of paradox" so it's okay for it to be a little non-literal. My interpretation of it, though, is that the soul is something impure that you must burn away, or maybe that the soul is polluted by our own words and behavior. It's definitely not meant to be scientifically accurate.

[kragen]

ash has no carbon

carbon's oxides are all gaseous at standard temperature and pressure

[lliamander]

Not quite. Plenty of carbon is release as carbon oxides, but calcium carbonate is also a major component of ash (or at least wood ash).

[kragen]

good point

little carbon, then, not none

[elihu]

Going by what wikipedia says, wood ash can have carbon. If I understand correctly, how much depends largely on how hot it burned.

https://en.wikipedia.org/wiki/Wood_ash#Elemental_analysis