("Wood Spirit"). - This is crude methyl alcohol, containing water and various impurities, chiefly acetone and esters. The amount of these impurities allowed to remain in the various grades of wood spirit depends upon the purpose for which the spirit is required. For example, in the making of formaldehyde, and also in the colour industry, it is important to have the methyl alcohol nearly free from acetone; whereas there is no objection to a moderate proportion of acetone in wood naphtha used as a denaturant of ethyl alcohol, and its presence is even advantageous in wood naphtha employed as a solvent for resins in making varnishes, polishes, and lacquers.

For a description of the analytical methods used in examining wood naphtha, and for typical analyses, see Chap. VIII.