Page:The New International Encyclopædia 1st ed. v. 05.djvu/572

* COTTONSEED AND ITS PRODUCTS. 488 COTTONSEED AND ITS PRODUCTS. before the invention of the cotton-gin in 1794, the utilization of i-ottonseed was attempted, and in 1770 samples of the oil were exhibited by the iloravians in liethlehem, Pa. Previous to that time the seed had been allowed to rot on the ground by many of the planters, while others more intelligent bad utilized it as food for cattle, sheep, and horses. Others dug furrow-trenches, and buried it in the rows on which the next crop of cotton would be planted. Some fed it raw to their stock, while others boiled it to make it possibly more palatable. In 1820 a patent was gi'anted for a process for extracting the oil, but the construction of the mills was so slow that at the end of fifty years only Iwenty-six cottonseed-mills had been erected. In 1861 'Jlr. Edward Atkinson stated that if the cotton-piant produced no cotton it w<iuld still be well wortli cultivating on account of the valuable ]iroducts that can be extracted from the seed. ■ This was fully realized toward the close of the nineteenth century, and the value of the cotton- seed began to be more generally apjireciated. Though much of it is still retained on the planta- tions as a fertilizing material, the amount manu- factured in the United States was, in ISDS, 5,594.- G02 tons, in 1899 4,450,000 tons, and in 1900 4,472,103 tons. The annual product is valued at $33,000,000. In addition to the oil extracted from thecotton- seed, it yields the following by-produets: Lint- ers, or short bits of lint that adhere to the seed in the ordinary process of ginning, and are stripped bv a specially constructed gin. These short fibres are used for the manufacture of bat- ling and wadding. Hulls, the outer casings of the seed, which make a valuable cattle-food, whose properties are discussed below. Oil cake, the material left after the oil is expressed out of the nut. This is also used as a cattle-food or as a fertilizer. Sludge, which settles at the bot- tom of the oil-tanks, and is used in the making of soap, stearin, etc. The process of manufacture is briefly as fol- lows: The seed is shoveled from the cars into conveyors, which are spiral screens revolving in troughs w-ith perforated bottoms through which any loose soil, sand, and stones are shaken. This process of cleaning is continued in a separator, where by means of different sized screens all dirt and impurities are removed. A strong magnet is also used to draw out bits of nails and other iron. The seed being sifted and cleansed, it is now passed through the linter, a specially constructed gin for removing these short fibres. The lint is ginned twice, the .second process removing the shorter fibres, so that two brands or qualities are thus obtained. The next process is to crack the hulls in a machine between revolving blades and oil : It ma}' be expressed directly from the cold meats, this process making a higli-grade oil; or the meats may first be heated in cookers. These cookers are steam-heated metal pans, covered with non-heat-conducting material and liolding 700 pounds. The seeds are cooked from one-quarter to tliree-quarters of an liour, according to their condition as detennined by the judgment of the operator, too little or too nuicli cooking giving a smaller yield of oil. The cooked meats are dropped into a camel's-hair sheet, spread out on a steel plate. ^Vrapped in this sheet the meats are subjected to pressure, which is gradually in- creased till it reaches 3500 jiounds per square inch. Under this pressure, a dark, murky oil flows out in streams and is received in reservoirs beneath the presses, whence it is pumped into settling-tanks. The cakes are now taken from their wrappings of camel's-hair, cooled, and dried. They are then cracked and ground into meal, which is shipped directly in sacks or pressed again into cakes. After the crude oil has settled it is drawn off and refined by treating it to a 10 or 15 per cent, solution of caustic soda and then allowed again to settle. As it settles the muci- laginous, albuminous, coloring matters and other impurities sink to the bottom, leaving a clear yellow oil, which may be still further filtered and purified if desired. The' white oil of commerce is produced by shaking up the oil with a 2 or 3 per cent, mixture of fullers' earth and then allowing it to settle. The commercial cottonseed-oils are classified as crude, summer yellow, summer white, winter yellow, and winter wliite. The winter oils are made !)y cooling the suninier oils to the freezing- point, when the palmitin crystallizes and the oil is pressed out of the remaining solidified ma- terial. Cottonseed-oil consists chiefly of palnia- tin and olein. the winter oils being almost entirely olein. It stands midway betA"een the drying and non-drying oils, its drying properties being in- ferior to those of linseed oil. ( See Oils. ) It soli- difies at from 32° to 38° F.. is almost odorless, and has a slight nutty taste. Its uses are constant Iv increasing. It is employed extensively in cooking and is also used as an adulterant of lard, olive oil, and other staples. By many it is preferred as a substitute for lard or butter, in cooking. It is used in pharmacy, in making soap and paint, as a lubricator and an illuminant. Consult Brooks, Cotton (New York, 1898). Feeding and Fertilizing Value. — Brief men- tion has already been matle of the use of cotton- seed products for feeding cattle and for fertilizer. Whole cottonseed has been sliown by a large number of analyses to range in composition as follows : Percentage Composition of Whole Cottonseed ■n-ater Ash Protein Fibre Nitrogen- free extract Fat Maximum 17.51 8.00 9.92 8.00 2.89 i.-H 29.70 13.62 19.38 32.40 17.60 22.57 36.70 7.58 23.94 29.34 10.40 19.45 bars, and then the meats and hulls are separated, the latter being sold either loose or in 100-pound bales. The meats are now ready to be passed through hea'y calender rolls to crush the oil-cells. There are two processes of making cottonseed- This material was used in the past to consider- able extent as a feeding stuff for cattle and sheep, and was fed either raw. cooked or roasted, but. with the advent of oil-mills, its use for this purpose is much less in the vicinity of these.