For general purposes the denaturant employed is a mixture of wood naphtha, pyridine bases, acetone oil, benzene, and colouring matter. Of this mixture, 3 litres are added to 100 litres of alcohol, which must not be of lower strength than 90°. Spirit so denatured is used for lighting, heating, and motor purposes, and for certain kinds of varnish.

Specially-denatured alcohol is allowed for use in various industries. The denaturants used are partly furnished by the authorities, at fixed prices, and partly by the users of the denatured spirit. If any alcohol is recovered during the manufacturing operations in which the denatured spirit is employed, it may only be used again for the same purpose, and if necessary must be again denatured. The special denaturants chiefly employed are as follows, per 100 litres of alcohol.

(1). For making ether. - One litre of sulphuric acid at 66° Be., 5 litres of crude ether residues, and 1 litre of crude benzol. Under permanent supervision, sulphuric acid alone may be employed.

1 Industrial Alcohol Committee, Report, p. 13.

(2). Varnishes. - Four litres of a mixture of wood naphtha, acetone oil, and crude benzol, with sufficient of the particular varnish to give 10 grams of fixed residue per litre.

(3). Mercury fulminate. - Crude residue from previous operations, 6 litres; nitric acid, 5 litres.

(4). Collodion, photographic paper, and artificial silk. - Three litres of acetone, 1 litre of light acetone oil, and 20 litres of ether. The ether alone may be used for the silk if under permanent supervision. On the same condition, ether in the given proportion may be used for denaturing alcohol used in making cinematograph films.

(5). Brewers' varnish. - Methyl alcohol 2 litres, fight acetone oil 2 litres, with 20 litres of shellac solution (50 kilos. of lac in 100 kilos. of alcohol).

(6). Lysoform. - 0.5 Litre of acetone oil, 3 litres of acetone, and 2 litres of formalin (40 per cent. strength).

(7). "Dermoid " varnish. - Two litres of methyl alcohol, 2 litres of acetone, and 4 litres of " Dermoid " varnish.

(8). Incandescent mantles. - 2.5 Litres of ether, 2 5 kilos. of camphor, 25 kilos. of castor oil, and 25 litres of collodion solution (6 per cent.).