If so, what about smells coming from solid matter, like wood?
No, smell is a sense. That is like asking if taste is a food.
Some gasses can be detected by our sense of smell as can some aerosols. I don't know if the scent of wood is carried by a gas or an aerosol.
An odor or odour or fragrance (commonly referred to as a smell) is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction.