1885.] Metals at High Temperatures in Fused Salts. 217 



ascertained resistances of the fused salts. The temperatures were 

 determined in a large number of observations by the aid of a Siemens* 

 water pyrometer. The salts employed as electrolytes were potassium 

 carbonate, potassium chloride, potassium nitrate, potassium chlorate, 

 potassium bisulphate, and sodium chloride, using platinum and copper 

 or iron as elements. The action of two dissimilar salts in contact 

 during fusion at 845° C. (K 2 C0 3 and NaCl) on the same metal, 

 platinum, was also observed, and considerable reversals of the E.M.F . 

 to the extent of 0'37 volt occurred apparently from divergence of 

 temperature in the relative rate of cooling from fusion of the two 

 salts. 



Table A* contains quantitative estimates in volts of the deviations 

 of the E.M.F. from the normal. The results on this Table A show 

 that by a regulation of the heat between the metals forming the 

 elements, extensive deviations from the normal electro- chemical 

 positions of the metals were obtainable, in connexion with some of the 

 above fused salts, under the conditions of temperature recorded on the 

 Tables A and B. In K 2 C0 3 , fused and resolidified (being then under 

 the fusing point), a reverse E.M.F. of 1*037 volts was noticed (platinum 

 positive), the current flowing from the platinum to the copper; 

 on remelting the salt and equalising the temperature throughout 

 to 845° C, an instant reversal of the direction of the current took 

 place, the metals resuming their normal positions with an E.M.F. of 

 0*22 volt, platinum being now negative. In the case of platinum 

 and iron, under the same conditions in the above salt, a total deviation 

 of about 0'88 volt from the normal position was obtainable (platinum 

 positive) . In the water tube experiments greater divergences were 

 noticed (see Table B). With potassium chloride, interchanges of 

 position between the metals occurred, platinum at first being positive, 

 with an E.M.F. of 0*318 volt, representing a total deviation of 0*94 

 volt. With potassium nitrate just before fusion point, an E.M.F. of 

 0'088 volt was observed (platinum positive) ; on the salt, however, 

 reaching fusion, a reversal took place, the copper assuming its normal 

 positive position. 



Table B contains estimates of the temperature conditions attending 

 the variations of the E.M.F. in fused K 2 C0 3 . Considerable reversals 

 of the E.M.F. were noticed (platinum positive). The experiments in 

 columns 1 and 3 show that a temperature divergence of about 260° C. 

 between the platinum and copper, gave a reverse E.M.F. of 0*44 volt 

 (platinum positive), a difference of 265° C. between platinum and 

 iron gave a reverse E.M.F. of 0'24 volt (platinum positive), the 

 E.M.F. reducing to a certain extent as the temperature difference 

 decreased. To obtain a greater difference of temperature between 



# The Tables A and B are not given in this abstract. 

 VOL. XXXVIII. 



