16 MODERN SCIENCE READER 



lating through the animal's system, attach to the wool of a 

 sheep. These products are used as a base for ointments 

 and toilet preparations, for dressings for leather, as a lubri- 

 cant for wool and other animal fibers, and in conjunction 

 with certain lubricating oils. At one large plant in Amer- 

 ica more than 200,000 pounds of wool are " decreased" 

 every ten hours. From two million to three million dollars' 

 worth a year of wool fat and potash are estimated to have 

 been wasted in the United States before the solvent process 

 of extraction came into general use. 



In the industries of cotton manufacturing and cottonseed 

 oil making, scarcely anything is allowed to go to waste. 

 For many years the seed of the cotton plant was regarded 

 as without value; now the cottonseed crop of the United 

 States is worth about one fifth of the total cotton crop of 

 the country. Among the principal uses of cottonseed oil 

 are its part in making lard compound and white cottolene, 

 both valuable food products. Cottonseed oil is also used 

 as a substitute for olive oil, by soapmakers in the making 

 of soap, by bakers, and also in the manufacture of washing 

 powders. 



The leather industry is equally saving in the matter of 

 wastes. In the tanning of leather, there are developed as 

 side products, scrap and skin, from which glue is made; 

 hair, from which cheap blankets and cloths are manufac- 

 tured, and waste liquors containing lime salts. By means 

 of a special apparatus scraps of leather are converted into 

 boot and shoe heels, inner soles, etc. What is called 

 "shoddy" leather is made by grinding the bits of leather 

 to a pulp, and then by maceration and pressure forming 

 them into solid strips. 



