27 CFR § 21.23 - Formula No. 19.

To every 100 gallons of ethyl alcohol of not less than 160 proof add:

4.0 gallons of either methyl isobutyl ketone, mixed isomers of nitropropane, or methyl n- butyl ketone; and

1.0 gallon of either kerosene, deodorized kerosene, gasoline, unleaded gasoline, rubber hydrocarbon solvent, or heptane.