348 



Scientific Proceedings, Royal Dublin Society. 



In this test the sample was heated to the highest temperature used, and 

 values obtained for descending temperatures. A few results obtained after 

 water had been substituted for mercury are given. This sample was cut 

 from a sheet of thick red fibre, and turned in a lathe to the tubular form. 

 It was found to be slightly swollen through absorption of water at the end 

 of the second test. 



Table 11. 



Red fibre ; thickness, 0'31 cm. 



a = 72 E. 



This sample was heated just above 70° C, and values for, descending 

 temperatures obtained. It was a piece of tubing of inner diameter T6 cms. ; 

 outer diameter, 2-22 cms. ; effective length, 3 - 7 cms. ; and closed at one end 

 with an ebonite stopper. This tube was not machined, but in the condition 

 supplied by the manufacturer, and had previously been stored in a dry room 

 for eight or nine months. 



The resistance of this sample is seen to be considerably greater than the 

 preceding one, and the decrease of resistance due to the use of water instead 

 of mercury electrodes is much less. 



It has been found by different workers that the value of a in megohms 



