CROP PLANTS FOR PAPER MAKING. 



(2) Pith pulp, suitable for pulp and paper specialties, such as insu- 

 lating material, grease-proof wrappers, pie plates, fiber boxes, and 

 possibly bottles. The yield of pith will range 

 from 1;") to 30 per cent of moisture-free stalks. 

 The usefulness of pith pulp for standard prod- 

 ucts is not as gi-eat as that of the long fiber, but 

 it is a plastic material that should serve many 

 useful purposes. The character of the fiber and 

 pith cells is shown in figure 1. 



(3) Cornstalk extract, the soluble solids of 

 the stalks, obtained by water extraction or by 

 saturation under pressure and subsequent ex- 

 pression. The method most commonly em- 

 ploj^ed in obtaining this extract is to place the 

 shredded stalks in the digester with a quantity 

 of water and boil for an hour under a steam 

 pressure of from 50 to TO pounds. The liquid 

 containing the soluble solids is then drained off 

 and evaporated to the desired consistency, while 

 the extracted stalks remain in the digester ready 

 for cooking with caustic soda. 



A ton of cornstalks will yield from 200 to 300 

 pounds of soluble solids containing the greater 

 part of the food value of the stalks. When 

 made under the best conditions from 8 to 12 per 

 cent of the extract is protein, about 25 per cent 

 is invert and cane sugar, and about 25 per cent 

 more is sugars of the pentose and pentosan class. 



About 25 gallons of extract of molasseslike 

 consistenc}^ were produced at a paper mill dur- 

 ing the summer of 1910, and a month's prelimi- 

 nary feeding test of two animals was made in 

 cooperation with the Bureau of Animal Industry 

 of the Department of Agriculture. All of the 

 food mixed with dry matter was eaten and no 

 injurious effects were observed. It remains to 

 make a conclusive test with a larger number and 

 a greater variety of animals before the nutritive 

 value of the material can be determined or 

 whether it is injurious if fed for a long time. 

 As broom-corn and sorghum stalks and rice 

 straw yield a similar extract, the possibility of 

 reclaiming the food elements will very likely be 



fJ^ 



\i^ 



Fig. 1. — Long fiber and 

 pith cells of Indian 

 corn.i (Enlarged 71 

 diameters.) 



iThe illustrations used in this circular were drawn by Mr. W. E. Chambers, 

 Office of Agricultural Technology. 

 [Cir. 82] 



of the 



