242 BELL SYSTEM TECHNICAL JOURNAL 



stantial practical improvements effected thereby. The increase of 

 resistance is of the order of 50 times. 



Fibers are classified according to their electrical behavior in a 

 manner which is also in harmony with their chemistry as follows: 

 (/) Animal fibers. 



These are of protein nature and are characterized by high moisture 

 content at ordinary humidities and by great electrical sensitivity to 

 further increments of moisture, yet possess excellent insulating 

 properties under usual atmospheric conditions. 

 {2) Vegetable fibers. 



These are of cellulosic nature and are characterized by lesser moisture 

 absorption and lesser electrical sensitivity to further increments of 

 moisture, yet possess relatively poor insulating properties over the 

 range of prevalent atmospheric conditions. 

 {2a) Cellulose acetate. 



This absorbs little water and accordingly has excellent insulating 

 properties under like conditions. 



The differences in electrical behavior of the two main classes of 

 textiles are believed to be due to differences in the space patterns 

 according to which water is distributed within the individual fibers. 

 The patterns are probably determined directly or indirectly by the 

 chemical composition of the fibers and associated with the colloidal 

 structure. 



The authors wish to acknowledge their indebtedness to their 

 colleagues, whose names appear as authors of kindred papers, for 

 their advice and assistance. Also we wish especially to thank Dr. 

 Homer H. Lowry, whose discernment has stimulated the development 

 of evidence necessary to several of the more important deductions. 



