CHEMICAL INVESTIGATION. 19 



which we do not produce commercially, but which are capable of 

 cultivation in the United States, and which will add to our national 

 resources. This work has been prosecuted by the importation and 

 distribution of the seeds of fiber plants, by encouraging and directing 

 field experiments, by testing fiber machines, and by affording informa- 

 tion, both through personal correspondence and through a series of 

 publications. 1 



CHEMICAL INVESTIGATION. 



In presenting this phase of the study of fibers I can but refer to the 

 valuable work that has been accomplished in England in the field of 

 chemical research by Messrs. Cross, Be van, and King, and I will 

 refer particularly to the Report on Indian Fibers 2 and the work on Cel- 

 lulose, 3 the latter being a recent publication. The methods adopted 

 in the chemical study of fibers and the processes essential to proper 

 determinations are as follows : 



Moisture. — All the celluloses hold in their ordinary state a certain 

 proportion of moisture, which, within the limits of variation (one-half 

 of 1 per cent) due to atmospheric changes, is definite and characteristic 

 of each fiber. It is noteworthy that the proportion of hygroscopic 

 moisture is an index of susceptibility of attack by hydrolytic agents; 

 it is certainly true that the textile fibers of the highest class are dis- 

 tinguished by their relatively low moisture. It is scarcely necessary to 

 say that the moisture is determined by drying a weighed quantity of 

 the fiber. It is necessary to raise the temperature to 110° to drive off 

 the whole of the water; at 100° a fiber will often retain 1 per cent of its 

 weight. Owing to the variations in this constituent, it is expedient to 

 express all the results of analysis as percentages of the dry fiber. 



Mineral constituents. — The ash left on incinerating the fiber is deter- 

 mined in the usual way. The proportion is low in the ligno-celluloses, 

 higher in the pecto-celluloses, especially when the proportion of non- 

 cellulose is high. Cellular tissue further contains a higher proportion 



1 The special reports issued previous to this work are : 



1. A Eeport on Flax, Hemp, Eamie, and Jute, Illust., pp. 104, 1890. 



2. Recent Progress in the Ramie Industry in America, pp. 16, 189T. 



3. A Report on Sisal Hemp Culture in the United States, pp. 59, Illust., 1891. 



4. A Report on Flax Culture for Fiber in the United States (and Europe), pp. 93, 

 Illust., 1892. 



5. A Report on the Leaf Fibers of the United States, pp. 73, Illust., 1893. 



6. A Report on the Uncultivated Bast Fibers in the United States, pp. 54, Illust., 

 1894. 



7. A Report on the Cultivation of Ramie in the United States, pp. 63, Illust., 1895. 



8. A Report on the Culture of Hemp and Jute in the United States, pp. 43, Illust., 

 1896. 



Five Annual Reports have been issued, which will be found in the Yearbook, or 

 Annual Reports of the Department of Agriculture, 1890 to 1895; also Farmers' Bulle- 

 tin No. 27, Flax for Seed and Fiber, pp. 16, 1895. 



2 See Cross, Bevan, and King, list of authorities. 



3 See Cross and Bevan. 



