A Black Substance That Comes From Burning Wood. Chimney soot is fine black or dark brown powder formed due to incomplete combustion of wood or coal in a confined place. Soot is formed in a temperature lower than 284 degrees.

Soot is formed in a temperature lower than 284 degrees. Chimney soot is fine black or dark brown powder formed due to incomplete combustion of wood or coal in a confined place. What is a black substance that comes out of burning wood?