Alcohols represent the first stage of oxidation of hydrocarbons in which one or more hydrogen atoms are replaced by hydroxyl groups. This methyl alcohol is derived from methane by synthesizing carbon monoxide or carbon dioxide. Ethyl alcohol is derived from ethane by fermentation of corn, potatoes, rye, and molasses. Methyl alcohol, methanol, or wood alcohol is a colorless liquid boiling at 64,7° C. It is very poisonous when its vapors are breathed in quantities; however, because of its low cost, it is used as a thinning agent in shellac coatings employed in techniques of image transposition. It may also be used in place of acetone for destroying the emulsion balance of water tusches. Ethyl alcohol, ethanol, or grain alcohol is seldom necessary for use in hand-printing processes.
Anna Trojanowska