INFLUENCE OF MOISTURE UPON INSULATORS 



231 



internal structure of the fibers, not by the twist of threads or the lay 

 of servings. 



The moisture content of each sort of textile depends directly on the 

 humidity of the atmosphere. Fig. 1 shows the best data available 

 for the moisture content of silk, wool, cotton, and cellulose acetate in 

 equilibrium with air over considerable ranges of relative humidity. 



65 67 69 71 73 75 77 79 81 83 85 87 



RELATIVE HUMIDITY — PER CENT 



Fig. 2 — Insulation resistance of J^ inch lengths of textile threads as affected by 

 relative humidity of atmosphere. The purified cotton and purified silk had been 

 submitted to a washing procedure to remove electrolytes. The impure silk was a 

 commercial specimen representing somewhat more than usual contamination with 

 electrolytes, while the commercial cotton is representative of its class. 



The data for silk and wool were taken from a paper by Schloessing; ^^ 

 those for cotton are due to Urquhart and Williams; " while those for 

 cellulose acetate represent the figures of Wilson and Fuwa,^- who also 

 give corresponding data for several textiles and many other substances. 

 It is sufficient for our present purpose to emphasize the orderly 

 dependence of moisture content upon the relative humidity of the 

 atmosphere without discussing secondary phenomena or the full 

 significance of the curves. 



The relation of electrical behavior of each textile to relative humidity 

 is also very close. Fig. 2 shows the insulation resistance of each of 



10 Schloessing, Th., Bid. Soc. Encour. Indnst. Nat. 8, 111 (1893); C. R. 116, 808, 

 1893. Text. World Record, Boston, Nov. 1908, p. 219. 



11 Urquhart and Williams, /. Textile Inst. 15, 143 (1924). 



12 Wilson, R. E. and Fuwa, Tyler, lud. &■ Eng. Chem. 14, 913 (1922). 



