Carburetting

from The Collaborative International Dictionary of English v.0.48

Carburet \Car"bu*ret\, v. t. [imp. & p. p. {Carbureted} or
   {Carburetted} (?); p. pr. & vb. n. {Carbureting} or
   {Carburetting}.]
   To combine or to impregnate with carbon, as by passing
   through or over a liquid hydrocarbon; to carbonize or
   carburize.
   [1913 Webster]

         By carbureting the gas you may use poorer coal.
                                                  --Knight.
   [1913 Webster]