BUTYL ALCOHOLS. Four isomeric alcohols of this for mula, are known; two of these are primary, one second ary and one tertiary (see ALcoHoLs). The two primary butyl alcohols arise during the high-pressure synthesis of methyl alcohol from carbon monoxide and hydrogen in presence of metallic catalysts (copper, cobalt, chromium, manganese, etc.) . Normal butyl alcohol, is a colourless liquid, boiling at 116.8°, and formed by reducing normal butyl aldehyde with sodium, or by a peculiar fermentation of glycerin, brought about by a schizomycete. The bacterial fermentation (Bacillus butyl icus) of various carbohydrates yields n-butyl alcohol and acetone in the proportions 2:1 by weight. Isobutyl alcohol CH2OH, the butyl alcohol of fermentation by yeast, is a primary alcohol derived from isobutane. It may be prepared by any of the general methods, and occurs in fusel oil, especially in potato spirit. It is a liquid, smelling like fusel oil and boiling at 108.4° C. Methyl ethyl carbinol, is the secondary alcohol derived from n-butane. It is a strongly smelling liquid, boiling at 99°. Trimethyl carbinol or tertiary butyl alcohol the simplest tertiary alcohol, was obtained by A. Butlerow in 1864 by acting with zinc methyl on acetyl chloride (see ALCOHOLS) . It forms rhombic prisms or plates melting at 25° and boiling at 83° ; it has a camphoraceous smell. Secondary butyl alcohol from butylene is obtained as a by-product from the petroleum cracking process (see PETROLEUM) .