CROP PLANTS FOR PAPER MAKING. 7 



manufacture of j^ressed-fiber utensils, such as -washtubs, trays, pails, 

 and many other products. 



The second means of securing pulp from raw materials has a far 

 wider application than the mechanical process. It consists in sepa- 

 rating the tissue cells from one another through the action of chemi- 

 cals which attack the gums, resins, and other cementing substances 

 which hold the parts of the plant together. Two classes of chemicals 

 are used, namely, acids and alkalis. A good example of a pulp pro- 

 duced by the acid method is the well-known sulphite fiber produced 

 so largely from spruce, and in less measure from other coniferous 

 trees. In this case sulphurous acid is the solvent. The alkali method 

 of digestion is suitable for a wider range of materials than the acid 

 method. In this case the chemical solvent generally used is caustic 

 soda. Practically all experiments with the w^astes or by-products 

 of crop plants and with wild plants other than trees are conducted 

 by the soda process and a variation of it known as the sulphate 

 process. In commercial practice the greater part of the soda pulp of 

 commerce is produced from poplar and certain other broad-leaved 

 trees, and from esparto, a grass that grows wild in the circum- 

 Mediterranean region. Chemical pulp, produced either by the sul- 

 phite or soda process, and pulp from rags are the bases of nearly all 

 of the better grades of printing, writing, and wrapping papers. 



REVIEW OF RECENT EXPERIMENTS.' 



During the past 10 years many crop materials have been subjected 

 to pulping experiments by some of the more progressive paper 

 manYifacturers and by private individuals. In most cases a satisfac- 

 tory quality of paper has been made, but in the end nothing practical 

 has come of the work. The whole situation might be summarized 

 by the statement that it has been found possible to make paper out 

 of many crop wastes, but it has been found impossible to make money 

 out of more than one or two. 



Congress, in making appropriations for the Department of Agri- 

 culture for 1908-9, provided the sum of $10,000 to be used in test- 

 ing " such plants as may require tests to ascertain if they be suitable 

 for paper making." One half of this fund was assigned to the 

 •Forest Service for studies of unused woods, the other half to the 

 Bureau of Plant Industry for the investigation of crop and wild 



1 The writer is indebtfd to Alossrs. F. P. Veitch and J. L. Merrill, of the Bureau 

 of Chemistry, and to Mr. E. M. Munccy. of the Office of Agricultural Technology, 

 of this Bureau, for all chemical determinations ; to Dr. H. S. Bristol and Mr. Edwin 

 Sutermeister, of the Forest Service, for assistance in much of the earlier work, and 

 to the Bureau of Standards, Department of Commerce and Labor, for testing the papers 

 produced in the many commercial and semicommercial runs at the paper mill. The 

 Bureau of Animal Industry, through Dr. E. C. Schroeder and his assistant. Mr. W. E. 

 Cotton, aided the work by conducting a preliminary feeding test of the extract obtained 

 from cornstalks. 



[Cir. 82] 



