4 CROP PLANTS FOE PAPER MAKING. 



Laboratory of the Forest Service. The second possible source is 

 among phmts other than trees. These are being investigated by the 

 Bureau of Phmt Industry, assisted in the chemical phases of the work 

 by the Bureau of Chemistry. So many extravagant statements have 

 been current from time to time that it seems wise, in the interest of 

 conservatism, to saj^ that the investigators of the Bureau of Plant 

 Industry hope only to find a partial substitute for wood and that there 

 in no expectation of " throwing a life line " to the pulp and paper 

 industry wdiich will afford instant and permanent relief from the 

 persistently rising cost of wood. 



ALL PAHTS OF PLANTS AND PLANT TISSUES ARE NOT OF EQUAL 

 VALUE IN PHODUCING PAPER FIBER. 



While j)aper of some kind can be made from almost every plant, 

 there is wide diversity in the quality and quantity of fiber produced. 

 Plants, as is well known, are made up of complex tissues containing 

 various kinds of cells. Paper pulp is made by liberating the individ- 

 ual cells comj^rising these tissues. This is accomplished by mechani- 

 cal means in the case of certain trees, and by chemical resolution, 

 commonly called digesting, in the case of nearly all other plants. The 

 pulpy residue of chemical treatment is in large part cellulose. It is 

 this substance that furnishes the basis of all papers. Cotton staple is 

 an almost pure form of cellulose, and the onl}^ one occurring in so 

 free a condition : that is, so completelj^^ disassociated from other tissue. 

 Cellulose wherever it occurs is an unusually stable compound, and as 

 chemical treatment of plant materials progresses it is the last to be 

 attacked by acid or alkali solvents. 



The quantity of cellulose-producing tissue varies gTeatly in differ- 

 ent 2)lants; hence, they are not of equal value for paper making. 

 Furthermore, there are differences in the kinds of cellulose produced 

 by different plants, and these kinds vary in value according to the 

 durability of the paper produced from them. 



CROP MATERIALS AVAILABLE FOR PRODUCING FIBER. 

 Outside of trees there are three classes of plant materials which 

 may be utilized in the production of paper pulp. These are: (1) The 

 wastes or by-products of cultivated crops, such as the stalks of corn, 

 broom com, and sorghum, the straws of rice, flax, and the common 

 grains, hemp waste, cotton stalks, cotton-hull fiber, and bagasse; 

 (2) certain plants that may possibly be cultivated with profit for 

 paper-making purposes, such as hemp, esparto, jute, E id alia japonic a ^ 

 okra, and some of the well-known Japanese paper plants; (3) wild 

 plants, including certain grasses, rushes, sedges, canes, weeds, and 

 wild fiber-furnishing plants like the yuccas, sotols, and agaves. 



X^The paper upon ivhich this page is printed was made from broom-corn 

 Mall-s, Jong fiber. See page 3. 

 [Cir. 82] 



