104 THE POPULAR SCIENCE MONTHLY. 



wrapped in sleep. Such is the summer repose or aestivation 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. 



WASTE PRODUCTS: COTTON-SEED OIL. 



BY FREDERIC G. MATHER. 



IT 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 de- 

 veloped, 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 by- 

 product 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 be- 

 longing 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 be- 

 tween 1871 and 1884, when over 6,000,000 gallons, valued at 

 $2,600,000, were exported. Since 1884 the export lias rapidly de- 

 clined, only 2,000,000 gallons, worth $1,300,000, being exported 

 of late years, because the demand in the United States has in- 

 creased. 



Nine tenths of the American product enters into the composi- 

 tion 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 



