According to the action of the alcohol upon the pomade or huile antique at ordinary or higher temperature, the process is called cold or warm infusion. Cold infusion furnishes the odor in a much more delicate and superior form than the warm. The cold infusion requires for complete solution of the aromatic four to six weeks; the warm, ten to fourteen days. Although the former consumes a much longer time, it is to be preferred, as the heat injures the odor. Pomades or huiles antiques are never completely exhausted by a single treatment with alcohol. Even when heat is employed they always retain a portion of the aromatic with great tenacity; a second and third infusion still abstracts odor from them, and finally nothing remains but pure fat with a pleasant odor which is stained and sold commercially as pomade under the name of the respective odor—violet, orange flower, reseda, etc.—or else is used over again in the factory for the extraction of flowers. Experience has shown us that it is best to infuse the pomades or huiles antiques twice in the cold and to use the two fluids united for the finest perfumes; the residue by warm infusion furnishes an essence of second quality, and superior pomades or fragrant oils. The infusion is generally effected in strong glass bottles of a capacity of three to five gallons; about five to six quarts of cologne spirit being poured over six to eight pounds or pints of fat or huile antique. In treating huiles antiques all parts of the oil should be brought into contact with the alcohol as much as possible, hence the bottles must be frequently shaken; a better plan is to bring the tightly closed bottles into an apparatus in which they are constantly agitated by rotation. Such an apparatus is easily made by placing the bottles in an inclined position between two rods fastened to a common axis which is kept revolving. The adjoining illustration (Fig. 32) shows such a contrivance which is required also in the manufacture of perfumes. The rotation may be effected by clockwork, water power, or any other motor. [Illustration: FIG. 32.] Pomades being solid must be divided into small pieces which may be done with a knife, but the following procedure is more suitable and less laborious. The pomade is placed in a tin cylinder four inches wide and about a foot high, which is open at one end, the other being closed with a tin plate having several fine openings. The cylinder filled with pomade is set upon the bottle containing the alcohol for extraction, and the pomade is pressed through the openings in the shape of thin threads by means of a piston.