Allen — The Insulating Properties of Erinoid. 



345 



The specific insulation resistance of erinoid and red fibre at different 



temperatures. 



The samples in a tubular form closed at one end, with mercury electrodes 

 unless otherwise stated, were heated in a sand bath. 



The results obtained for black, red, and white erinoid are given in Tables 

 7, 8, and 9 ; and for two samples of red fibre in Tables 10 and 11. The 

 method of entry of these results is used in order to discover whether or not 

 a certain simple relation holds between resistance and absolute temperature. 



The thickness of the walls of the tube is given and also the value of <r in 

 terms of E, Unless otherwise stated the inner diameter of the tube was 

 1-55 cms. and the effective length, which differed slightly in these samples, 

 corrected for the closed end of the tube was about 46 cms. 



Table 7. 



Black erinoid ; thickness 047 cm. 



<r = 61-3 E. 



