Those most frequently used are the apricot and peach, since these oils contain the characteristic principle which gives the bitter taste to the kernels of this class in fruits. Often almond oils are offered to the trade which are composed exclusively of peach-kernel or apricot-kernel oil. Whenever the iodin number of an almond oil runs very high it is an indication that it is composed largely of peach or apricot oil. The detection of small quantities of these oils when added to almond oil is a very difficult matter and can only be accomplished by the expert chemist.
Cottonseed Oil.—One of the most important edible oils in the world, and especially from the point of view of production in the United States, is that derived from the seed of the cotton plant (Gossypium herbaceum).
The cotton plant grows over a wide area in the United States, including all of the southern states and extending into southern Virginia, southern Kentucky, southern Missouri, and Oklahoma. In former years the cotton plant was cultivated solely for its fiber. It is only in the last quarter of a century that the high value of its seed for many purposes has been realized. The seed of the cotton plant is preëminently rich in oil and protein. It contains traces of certain poisonous alkaloids, betain and cholin, the presence of which renders its indiscriminate use for cattle food in some cases dangerous. In the preparation of oil, however, no trace of these poisonous substances is found, since they exist solely in the non-fatty tissues of the seed. The production and refining of the oil has now grown to be a great industry and has already added much to the wealth of the cotton growers and the comfort and nutrition of the people in general.
Magnitude of the Cottonseed Oil Industry.—The average cotton crop of the United States is about 12,000,000 bales of about 500 pounds each. For every bale of cotton there is produced 1,000 pounds of seed. This would make the average cottonseed crop of the country about 6,000,000 tons. It is estimated that not over two-thirds of this is used in the mills; this would make about 4,000,000 tons. The average yield of 40 gallons to a ton shows the production of crude oil to be 3,200,000 barrels of 50 gallons each. This oil in refining loses on the average about 8 percent, which would leave 2,944,000 barrels of refined oil for edible and other purposes. Not less than two-thirds of this oil is used for edible purposes. A conservative estimate would place the quantity used for food between two millions and two millions and a half barrels per annum. The quantity varies with the prices of other fats.
Cotton seed is brought to the mills from the gins either by rail in box cars or in wagons. On arrival at the mills, it is stored in large sheds, known as seed houses. A single seed house will often contain as much as 5,000 to 10,000 tons. The seed is carried into the mill by means of conveyers. It first goes through coarse screens which remove the greater part of the trash and sand, after which it is passed over magnetized iron plates which remove nails and pieces of iron
