WASTE PRODUCTS: COTTON-SEED OIL. 107 



as seventeen dollars a ton, but there is no profit to the millers 

 if they pay much over twelve dollars. A sharp competition 

 among them led to the forming of an association of the mills 

 in 1878, which was the forerunner of the American Cotton-seed 

 Oil Trust. The Southern States are now divided into districts, 

 each one supplying certain mills, and keeping a uniform price 

 for the seed. 



The bulk of the supply is obtained from plantations immedi- 

 ately upon the Southern rivers, because the seed can be trans- 

 ported at little cost. The mills are also located upon the rivers. 

 Once landed at the mills, the seed is conveyed in an elevator to a 

 screen, or cylindrical sifter, where it is shaken until it is free from 

 dust and sand. Then it is blown against another screen to remove 

 stones, iron, and other foreign substances that might injure the 

 rollers. A second elevator carries the seed to the loft, where an- 

 other sifter separates the seed proper from the bolls or outside 

 hulls of the cotton bloom. No matter how close the picking may 

 have been, the bolls still have cotton sticking to them, and they 

 are dropped into a gin to remove the lint. This is known as 

 " crapo cotton," the only variety of linter produced in the mills. 

 The seed having fallen through the screen, is carried along an- 

 other screen or gutter directly over the gins. They drop through 

 holes in the screen upon the gins ; but when the box above the 

 gin is full the hole is closed automatically, and the screen carries 

 the seed forward to the next box, thus keeping all the boxes full. 

 The gins differ from cotton gins in having one hundred saws 

 instead of sixty. The saws are but half an inch apart and the 

 teeth are very firmly set. The problem of wholly removing the 

 lint, save by chemical process, has not yet been solved. 



Once thoroughly separated from all foreign substances dust, 

 bolls, and cotton the seed is conveyed to the roller, a revolving 

 cylinder containing twenty-four knives and four back knives, 

 which cuts the hulls from the kernels. This process was formerly 

 carried on by grindstones. The hulls go upstairs, where they are 

 again treated to find such kernels as may still be clinging to 

 them, after which they are sold or used as fuel in the furnace of 

 the mill. Only half of them are needed for this purpose, the 

 other half being sold as food for cattle. The ashes of the hulls 

 make an excellent lye for soap or for the refining of the oil. The 

 kernels are conveyed to rollers, where they are crushed very fine. 

 They are thence removed to the heaters, being agitated all the 

 time so as to give an equal exposure and allow the oil to be more 

 readily extracted. The kernels are then placed in woolen bags 

 packed between horse-hair mats, backed with leather, and hav- 

 ing a fluted surface inside to allow the oil to escape more free- 

 ly. The hydraulic pressure, furnished by the oil itself instead 



