About one fifth of the whole plant by weight consists of the seed, and an analysis of this shows them to be composed of water, ash, nitrogen, phosphoric acid, potash, soda, lime, magnesia, sulphuric acid, ferric oxide, chlorine, and insoluble matter.
As a commercial product seeds are exceedingly valuable, and yield the following substances:--oil, meal, hulls, and linters. When the hulls are ground they receive the name of cotton seed bran. The inside of the seed, when the hull has been removed, is often called the kernel and is sometimes also designated peeled seed, hulled seed, and meats. It is this kernel seed which, when properly treated, yields large supplies of oil and meal.
There are several classes of agents all of which act injuriously more or less on the Cotton plant.
1. Climatic changes, including hygrometric variations of the atmosphere, and extremes of heat and cold.
It has been pointed out in the early pages of this story, how very sensible to changes of heat and cold, the Cotton plant is, especially in the early growing period. When the plant has just risen above the ground, and is beginning to spread its roots, too great an amount of heat would be fatal to its further growth.
Instances could be given where very serious decreases in the production of cotton in the States especially have taken place, due entirely to unusually high temperatures which obtained during the early growing period of the Cotton plant.
Extremes of frost are likewise fatal to the growth of the young plant. By the beginning of April, frosts have as a rule disappeared, and no further fear need be felt on that account, though if the end of winter has been abnormally warm, and the young plants have been making leaf too quickly, it will be readily seen how fatal a sharp frost or two must be to the young and tender plant. There are cases, however, when a frost is beneficial.
Then again, while rain is needed in fair quantity, too much of it is followed by rot and myriads of pests. If the planter desires anything at all when his crop is ripe, it is fine weather in which to gather his harvest.
Frequently large quantities of cotton are left on the plantations, because it is too wet to gather it. This happened a few years ago to an unusual extent, when a vast quantity of cotton had to be left upon the fields.