Fire is the Dissociation of atomic and molecular substances into finer substances such as plasma, heat and light. The flame of fire is a combination of different plasmas or what used to be called ether and phlogiston earlier.
"Like fire, which is a spiritual order of vibration, spirit is latent in all matter. One might as well try to operate a steam-engine without its boiler as to give motion to matter against the conditions imposed by nature, or to propose a new method of controlling the action of our physical organisms (other than through the sympathetic transfer of our mental forces) as an improvement on the one instituted by the Almighty." [Newton of the Mind]
spiritual order of vibration
7B.09 - Luminiferous Ether or Light