350 



Scientific Proceedings, Royal Dublin Society. 



In 1908 Rasch and Hinrichsen 1 showed that the relation between insula- 

 tion resistance and temperature for certain materials including porcelain, 

 glass, and oil was a simple one, namely 



a and b being constants for a given material. 



The straight lines of Fig. 3 show that this relation is also true for erinoid 

 and red fibre. 



The lines for red, white, and black erinoid show by their approximate 

 parallelism that the variation of the resistance of these samples with 

 temperature is similar ; but this is not the case with the two different samples 

 of fibre. The insulation resistance of red erinoid is seen to be lower than 

 that of the other varieties of erinoid as shown previously in Section 4 of 

 Table 2. 



Insulation resistance and thickness of sample at different temperatures. 



From the same rod of white erinoid four cylindrical tubes, each closed at 

 one end, were turned in the lathe, and then tested at different temperatures. 

 The results are given in Tables 9, 12, 13, and 14. 



Table 12. 



White erinoid ; thickness, 0'6o cm. 

 a = 42 E. 



1 Zeit. fur Elektrochem., vol. xiv, 1908, p. 41. 



