BOTANICAL ASPECTS OF PAPER-PULP AND TANNING INDUSTRIES 509 



apart from the food and construction value, respectively, of comestibles and 

 woody plants. 



Though without documentary evidence to support such a contention, it 

 seems safe to state that at least one-half of all processed and manufactured 

 products of modern industry throughout the world are plant products in one 

 way or another, and that one-half of the other half is dependent on some plant 

 product somewhere along the line — witness, for instance, the role of plant 

 tannins in drilling muds; of a palm resin, dragon's blood, in photoengraving; 

 and of diatomaceous earth in countless filtering operations. 



Plant explorers have contributed to this development by finding the valu- 

 able plants in the wild; taxonomists have contributed by establishing their 

 identity and that of related species which may possess similar desirable quali- 

 ties; and plant breeders have improved upon the plants originally found in 

 the wild by the explorers. The significant advances have resulted, however, 

 from progress in engineering and applied chemistry, stimulated by favorable 

 economic factors that have made the progress and changes in plant utiliza- 

 tion feasible. The areas of enterprise in which industrial plant utilization have 

 thus advanced are numerous, and the history of two of them is briefly surveyed 

 in the following. 



Paper pulp. Prc-wood-pulp era. Ancient Egypt of 2000 b.c. is frequently 

 referred to as the birthplace of paper, that is, of the writing material which 

 the Romans called "papyrus," from the earlier Greek name for the material. 

 Papyrus was a compressed laminated sheet of reed stalks (Cyperus papyrus) 

 and as such was not paper in the modern sense of the term. 



Paper is, as it has been for over 1,850 years, a felted sheet of individual, 

 separated, microscopic plant cells obtained as a pulp by treating vegetable 

 material in a variety of ways. Some 2,000 kinds of plants have been found 

 to furnish cells, referred to as "fibers," suitable for this purpose. Discovery 

 of such utilization has been credited to one Ts'ai Lun of China in 105 a.d. 

 It is not known whether he actually made paper himself, but it is recorded 

 that he presented such material to the Emperor that year. A biography of 

 this man, compiled in the fifth century of our era, states that it was he "who 

 conceived the idea of making paper from the bark of trees, hemp waste, old 

 rags, and fish nets." 



In the course of the next thousand years the art of papermaking progressed 

 by way of Mongolia, Persia, and Arabia into North Africa. In the twelfth 

 century it entered Europe with the Saracens by way of Spain and then slowly 

 became established in various centers on the Continent. 



In America, in what was later to become the United States, the first paper 

 mill was established near Germantown, Philadelphia, in 1690 by William 

 Rittenhouse who had worked as a papermaker in Amsterdam, Holland. By the 

 time of the American Revolution, British America had other mills in the Colo- 

 nies of New Jersey (1726), Massachusetts (1728), Maine (1731-1734), 



