The use of denatured alcohol duty-free for industrial and general purposes is comparatively recent in the United States. Though the principle had been recognised by Congress many years previously, it was only in 1906-7 that effect was given to the recognition.

Two varieties of. "completely denatured" alcohol are now sanctioned: -

(1)

To 100 gallons of ethyl alcohol are added 10 gallons of wood spirit and 1/2 gallon of benzine.

(2)

To 100 gallons of ethyl alcohol are added 2 gallons of wood spirit and 1/2 gallon of pyridine bases.

The wood spirit, benzine, and pyridine bases must be of approved quality.

"Specially denatured" alcohol is sanctioned for use in certain industries according to the following list. All the quantities arc; referred to 100 (American) gallons of plain spirit.1

(1)

For preparation of lac varnish, collodion varnish, photographic plates, embalming liquids, making barometers and thermometers, and production of such articles as heliotropine, podophyllum resin, etc.: -

1 One American gallon = 3.785 litres = 0.833 Imperial gallon.

5 gallons of approved wood spirit. (2). - For celluloid, pyralin and similar products: - Seven pounds (American) of camphor and 5 gallons of commercially pure methyl alcohol having sp. gr. lower than 0.810 at 60° F., or alternatively, 2 gallons of wood spirit and 2 gallons of benzine.

(3)

For transparent soaps: -

6 1/2 Gallons of the following mixture, viz., 5 gallons of commercially-pure methyl alcohol as defined in (2), with 1 gallon of castor oil and gallon of soda-lye at 36° Be.

(4)

For preparation of tobacco (smoking and chewing): - One gallon of the following mixture, viz., 2 gallons of an aqueous solution of nicotine (40 per cent.), 04 lb. of an acid yellow colour, 04 lb. of blue colour tetrazo-brilliant 2B, and water sufficient to make 100 gallons.

(5)

For photogravures: -

Sixty-five lb. of ether, 3 lb. of cadmium iodide, and 3 lb. of ammonium iodide.

(6)

Mercury fulminate: -

Five gallons of commercially-pure methyl alcohol as defined in (2) and 1/2 gallon of pyridine bases. (7). - For use in watch-making: -

Five gallons of commercially-pure methyl alcohol (sp. gr. less than 0 810 at 60° F.), 1 1/2 lb. of potassium cyanide, and 1/8 oz. of blue colour B (sodium or magnesium salt). The blue colouring matter is dissolved in the methyl alcohol, and the potassium cyanide in a small quantity of water: these two solutions are then mixed with the 100 gallons of alcohol to be denatured. (8). - For preparation of sulphomethane: - One gallon of pyridine bases and 1 gallon of benzol. (9). - For purification of caoutchouc: -

Ten gallons of acetone and 2 gallons of mineral naphtha having sp. gr. between 0.650 and 0720 at 60° F. (10). - For pastes and varnishes with gun-cotton basis: - Two gallons of wood spirit and 2 gallons of benzol. (11). - For photographic collodion: - One hundred lb. of ether and 10 lb. of cadmium iodide.