Manchester Memoirs, Vol. xlii. (1898), No. 5. 3 



they rested on the ebonite. An electric current was then 

 sent through the spiral coil, the temperature of the upper 

 disc was raised, and heat flowed through the glass plate and 

 liquid to the lower disc and water bath. The tenapera- 

 tures of the various discs, when " steady," were determined 

 by means of thermojunctions soldered into holes in the 

 discs, a galvanometer, and a wire of known resistance 

 through which a known current was passing. 



The following results have been obtained for a mean 

 temperature of I5^C.: — 



Substances. Thermal Cofiductivity (c.g.s. units) 



Water '0014 



Sulphates. 



CUSO4 + 5H2O between '0017 and 'ooiS 

 ZnSO^+yHgO „ 14 „ 15 



FeSO^+yHaO „ 13 „ 14 



NiSO^+yHaO „ n ,, 12 



MgSO^+yHaO „ II ,. 12 



Sulphides. 









FeS 





about 



•017 



CuS 





about 



•014 



PbS 





between •oo]5 and "0016 



Oxides. 









AW, 



(Emery) 



about 



•025 



ZnO 







•009 



CuO 







•008 



PbO 







•005 



PbsO^ 







•005 



Fe.03 







•003 



MgO 







•003 



Chlorides. 









KCl 







•014 



NaCl 







•013 



PbCl, 







•0013 



CuCl, 







•0013 



