360 



EDNA D. SAYCE. 



Table I. — Conductivity of Vitreous Selenium. 



Disc 2, prepared on 21 August, 1916. 



Thickness of disc = 0*7523 cm. 



** ead - Date 



Temperature 



Temperature 



gradient 



across disc. 



.Heat supplied 



Thermal 



ins. j ^ ate ' 



of disc. 



(calories per sec.) 



Conductivity. 



(i) 



22 Aug., 1916 



23-80 0. 



5-39 



0-1724 



0-000324 



(ii) 





23-92 



5-46 



0-1724 



0000319 



(iii) 



23 Aug., 1916 



33-69 



4-93 



0-1651 



0-000345 



(iv) 





35-94 



4-98 



0-1650 



0-000342 



(v) 



24 Aug., 1916 



40-92 



4-80 



0-1655 



0-000358 



(vi) 





41-21 



4-79 



0-1655 



0-000359 



(vii) 



25 Aug., 1916 



24-17 



5-03 



0-1638 



0-000333 



(vm) 





24-46 



5-05 



0-1638 



0-000332 



(ix) 



28 Aug., 1916 



57-15 



4-49 



0-1676 



0-000385 



(x) 





57-48 



4-45 



0-1676 



0-000389 



(xi) 



29 Aug., 1916 



25-14 



5-03 



0-1638 



0-000337 



(xii) 





25-17 



5-00 



0-1638 



0-000339 



Table I, which shows one complete set of measurements 

 for the vitreous disc 2, indicates the typical increase in 

 conductivity which accompanies increase in the tempera- 

 ture of testing. This feature is common to both vitreous 

 and crystalline preparations, as is shown in Table II. 



Table II. — Thermal Conductivity of Crystalline Selenium. 



Disc C, prepared at 180° C. on 15 June, 1916. 



Thickness of disc = 0-5774 cm. 





Date. 



Temperature 

 of disc. 



Thermal 

 Conductivity. 



Electrical 



Conductivity 



(in arbitrary units) 



I. 



19 July, 1916 



20 July, 1916 



21 July, 1916 



24 July, 1916 



25 July, 1916 



26 July, 1916 



26-90 0. 



35-69 



46-01 



26-37 



52-61 



27-05 



0-00150 

 0-00152 

 0-00158 

 000151 

 0-00159 

 0-00152 



1-55 

 3-76 

 4-63 



4-56 

 1-58 



II. 



15 Sept., 1916 



18 Sept., 1916 



19 Sept., 1916 



20 Sept., 1916 



32-44 

 41-10 

 52-59 

 32-41 



0-00104 

 0-00109 

 0-00116 

 0-00104 



0-94 

 1-60 

 2-43 



0-96 



III. 



3 July, 1917 



4 July, 1917 



5 July, 1917 



6 July, 1917 



28-48 

 56-46 

 27-19 

 27-16 



0-00099 

 0.00134 

 000111 

 0-00110 





