Page:Popular Science Monthly Volume 45.djvu/116

104 wrapped in sleep. Such, is the summer repose or festivation of the tropical tree snails. For months of bright, sunshiny weather they cling motionless, perched aloft on their favorite trees that at once are home and food for them, firmly attached by a leathery epiphragm that neither sun nor rain nor wind, or anything but themselves, can dissolve; and on the coming of the first showers of the rainy season they awaken to new activity and life.



T has been stated that if the waste products of the world had been saved they would sustain the present population for more than a hundred years. Foreign countries give more attention than America to saving the waste. But as the population of the United States increases, and as processes of manufacture are developed, discoveries are made which turn the waste of former products into useful articles of commerce. Glycerin, wood acid, crude petroleum, and even the fine dust from anthracite coal have an importance to-day that they did not have formerly.

Cotton-seed oil is a most conspicuous instance of an article once thrown aside as a nuisance. Originally it was only a byproduct in the manufacture of meal from the seed; and even after it was discovered that meal could be made, it was a question what should be done with the oil.

That question has been answered in various ways. What was garbage in 1860 was a fertilizer in 1870, cattle food in 1880, and table food and many things else, in 1890. A small quantity of the oil is made in England, but it is inferior to the American article because the seed comes from Egypt or India. The American cotton parts with its fiber more readily. The best oil is made from seed belonging to the Southern upland cotton, that from the seaboard having a darker color. The exports are chiefly from New York and New Orleans, and the greater part goes to France, Italy, and the Netherlands. There was a constant increase of exports between 1871 and 1884, when over 6,000,000 gallons, valued at $3,000,000, were exported. Since 1884 the export has rapidly declined, only 2,000,000 gallons, worth $1,300,000, being exported of late years, because the demand in the United States has increased.

Nine tenths of the American product enters into the composition of foods, chiefly for salad and cooking oils and for the making of refined lard. The latter use is the most important of all. Nearly forty years ago the oil was mixed with lard for use in cold 