16 CROP PLANTS FOR PAPER MAKING. 



the expense for raw material. It requires from 3 to 4 tons of straw 

 to make 1 ton of tow, and medium tow is worth over $20 per ton at the 

 tow mills. Flax straw must be regarded as one of the most promising 

 materials, but extreme caution should be used in its exploitation. 

 Straw from different sources differs in strength and quantity of fiber; 

 climatic conditions appear to have a profound effect upon its fiber 



value. 



MISCELLANEOUS CROP MATERIALS. 



In addition to the crop by-products that have been discussed there 

 are other materials that may prove of value. Among these are the 

 common grain straws, the wastes of hemp, jute, flax, manila, and 

 other fiber crops, and the stalks of the grain sorghums which are now 

 being cultivated in considerable areas and whose culture is being ex- 

 tended rapidly. Epica7npes macronra^ a southwestern grass, which is 

 especially plentiful in Mexico, may prove useful, as it has an excel- 

 lent fiber. This plant, which is known as " zacaton," furnishes the 

 so-called " rice roots " so extensively used in the making of brushes. 

 In the brush industry only the roots are used, and the tall-growing 

 stems and leaves with their fine fiber are a waste product. 



Two points should be borne in mind in all attempts to make pulp 

 from croj) wastes: That not all materials are suitable for making 

 expensive products and that it not infrequently happens that there 

 is as much profit, because of lessened cost of production and greater 

 demand, in making cheaper products for which the material may 

 be better adapted as in making the higher priced articles. 



PLANTS THAT MAY BE GROWN AS PAPER CROPS. 



In addition to the waste materials that are available, evidence 

 has been gathered that certain crops can probably be grown at a 

 profit to both the grower and manufacturer, solely for paper-making 

 purposes. One of the most promising of these is hemp. Hemp 

 grows well in most parts of the country and produces very high 

 yields of raw material. The average production of " hay-dry " 

 hemp stalks per acre will reach very nearly 5 tons. Of retted stalks, 

 an average of from 2^ to 3 tons can be expected. When dew retted, as 

 is the common practice, the tax on the soil of growing the crop is 

 very light — an exceedingly important point in farm economics. 

 According to careful estimates by Prof. L. H. Dewey, hemp can be 

 grown through the retting stage at a cost of about $14 an acre. 

 With an average yield of 2^ to 3 tons of retted stalks, it seems very 

 likely that hemp can be grown profitably solely for paper stock. 



Hemp produces a paper of great durability and great strength 

 in thin sheets. The retted stalks will yield from 40 to 45 per cent of 

 cellulose. The fiber (fig. 3) is of such a nature and length as to fit 



e^The paper upon which this page is printed was made from rice straw and 

 spruce ivood. See page 3. 

 [Cir. 82] 



