Allun — The Insulating Properties of Erinoid. 



355 



The sample was first heated to just above 80° C. and values obtained for 

 descending temperatures. Graphite in the form of fine flakes was then 

 substituted for the mercury and a few values found. After this, water 

 electrodes were used ; care being taken to keep the upper part of the sample 

 which projected above the surface quite dry. 



a ooo 



i«oo 



I Id 00 



11+00 



60 



S 



iaoo 



£ 1000 



'■§ Boo 



•H fcoo 



^00 



aoo 



10 



ao 



70 



%0 



30 u-o 5o 



Temp. Deg. Cent. 



Fig. 5. — The effect on the insulation resistance at different temperatures of hlue erinoid, by 

 using various contact electrodes. Curve A is for graphite ; B for mercury ; C for 

 water ; D for mercury after 1 J hour's drying in air at ordinary temperature. 



The sample after the latter test was carefully dried with a cloth and 

 allowed to dry in the air of the room for 1£ hours. With mercury electrodes 

 the sample was then raised to a temperature of about 80° C, and afterwards 

 values were obtained at descending temperatures. 



SCIENT. PEOC. E.D.S., VOL. XV., NO. XXIX. 



3L 



