28 



after having been previously ground to a fine meal. The average 

 composition of the whole cob, calculated from a mean of 18 analyses, 

 is as follows: 



Per cent, i Per cent. 



Moisture 10.7 | Ash 1.4 



Proteids 2. 4 | Crude fiber 30. 1 



Ether extract 5 j Carbohydrates not crude fiber 54. 9 



The cob contains a small interior core of fine pith. In the separa- 

 tion of the pith from the exterior substance the following proportions 

 were found : 



Percentage of pith 1.5 



Percentage of shell 98. 5 



The pith of the corncob has many of the properties characteristic 

 of that of the stalk, is finer in texture, however, and less absorptive. 

 By experiment it was found that one gram of the air dry pith absorbs 

 10.43 grams of water. The chemical composition of the pith and the 

 shell of the cob are found in the following table: 



Chemical composition of corncob. 



Maize cobs are used to a large extent in the manufacture of pipes for 

 smoking tobacco. 



MANUFACTURE OF STARCH. 



Practically all of the starch which is made in the United States is 

 made from the grains of the Indian corn. In a few localities a small 

 quantity of starch is made from potatoes, and in Florida and some other 

 parts of the South still smaller quantities from the cassava. The starch 

 of commerce, however, for the whole country is derived exclusively 

 from Indian corn. The grains of the Indian corn contain from 60 to 65 

 per cent of starch, and nearly all of this is secured in commercial 

 operations in a merchantable form. The process of starch making is 

 extremely simple. The grains are softened in hot water until they can 

 be easily crushed between stones or rollers into a fine pulp. This pulp 

 is carried onto shakers lined with fine cloth, and as the pulp passes over 

 these the starch is washed through the meshes of the cloth by a stream 

 of water. It is customary in some localities to treat the separated 

 starch with a dilute alkali, usually caustic soda, for the purpose of 

 freeing it more completely from attached particles of a nitrogenous 



