The actual amounts differ with different varieties, conditions of cultivation, methods of ginning, &c.; a recent estimate in the United States gives 35% of lint for Upland cotton and 25% for Sea Island cotton as more accurate.
The average of a large number of analyses of Upland cotton seed gives the following figures for its fertilizing constituents: - Nitrogen, 3.07%; phosphoric acid, 1.02%; potash, 1.17%; besides small amounts of lime, magnesia and other valuable but less important ingredients.
After the seed of Upland cotton has been passed through a fine gin, which takes off the short lint or linters left upon it by the farmer, it is passed through what is called a sheller, consisting of a revolving cylinder, armed with numerous knives, which cut the seed in two and force the kernels or meats from the shells.
In the lower river lands Egyptian cotton has been the most successful, whilst Upland cotton is more suited to the highlands.
When the spinner has informed the dealer exactly what quality of cotton he needs, the dealer quotes so many " points on or off " the " future " quotations prevailing in Liverpool at the time of the purchase, which refer to Upland cotton of " middling grade," of " no staple " and of the worst growth.