Treatment of air dried and ground wood samples with different solvents at different temperatures and pressures gave yields of extracts which increased from 6.8 to 16.2 % as the pressure of the extraction increased from 6.0 to 17.5 MPa by supercritical-gas extraction. The samples suspended in water or water-solvent mixture containing alkaline catalysts (sodium carbonate, sodium hydroxide or sodium zincate) have been converted completely or partly to an oil, water-soluble chemicals and gases if subjected to heat in an autoclave. The yields of catalytic extraction have been increased from 14.3 to 42.5 % as the temperature increased from 438 to 603-degrees-K.