40 



" patiently saved generation after generation of seeds from the 

 plants that survived each successive winter, planting new fields 

 to replace the deteriorated ones on his own farm, and selling his 

 surplus seed to his neighbors. He was probably oblivious both 

 to the difficulty of the task he had undertaken and to the great 

 value of the result, and took as a matter of course the yearly de- 

 generation of his stands," until now the Grimm strain is recog- 

 nized as one of the hardiest ; it " is undoubtedly the direct prod- 

 uct of fifty-one years of perpetuation of fit and elimination of 

 unfit individuals under climatic conditions whose rigors are un- 

 known in Germany." 



Robert Kennedy Duncan in his recent book, " The Chemistry 

 of Commerce," has a chapter on cellulose which is written in a 

 manner making it equally interesting to a scientist or to a novice 

 in the field. He shows the stupendous industrial utility of cellu- 

 lose and the immense value of each fact gleaned from the field of 

 cellulose research. At present, although one third of the dried 

 vegetable matter of the world is cellulose, it cannot be synthesized 

 in the laboratory and very little is known about it. 



One class of cellulose industries is based on its inertness and 

 resistivity to the disintegrating action of air and moisture. First 

 in importance comes paper, both that made from the comparatively 

 pure cellulose of rags and that from wood pulp. As most of the 

 cellulose in wood exists chemically encrusted with other sub- 

 stances, the problem has been either to manufacture the paper 

 directly from wood, in which case it does not last, or to devise a 

 means of extracting the pure cellulose. This has been done 

 but the resulting cellulose is not so pure as that from cotton. 

 Another important cellulose industry, the making of fabrics, has 

 almost reached perfection. One interesting phase is the merceri- 

 zation of cotton by the application of caustic soda. Twine and 

 rope are also cellulose products. Out of the 1 10,000 species of 

 flowering plants that exist in the world, the fiber-making possi- 

 bilities of only half a dozen are used. 



Cellulose also has merit as a chemically active body. Dis- 

 solved in one substance it forms vulcanized fiber or may be car- 

 bonized for incandescent lig-ht filaments. When treated in another 



