J 5fi 



from tliose of Schenck and Hempei.mann, we repeated the pressure 

 measuremenis vvitli mixtures of dilferent composition. From table III 

 wherein the resuhs are indicated, it appears, however, tiiat this 

 exerts no influence on the equilibrium pressure, so that the existence 

 of solid solutions is excluded. 



TABLE III. CujS + 2CUSO4 ~t 2Cu.;0 + 3SO2 (fig. 2 line II). 



2 CuSO. on 1 CuoS. 



T 



1 CUSO4 on 1 CU2S. 



300 



310 



350 



360 



377.5 



390 



400 



135 

 148 

 210 

 245 

 285 

 443 

 517 



327 

 351 

 375 



175 



228 

 350 



We have not been able to contirm the phenomenon observed by 

 the said investigators that, above 300^, the equilibrium pressure first 

 attains a maximum value and then fails to a constant terminal value. 

 Although we kept the mixture, after the setting in of the equilibrium, 

 for fully 5 X 24 hours at ± 320°, no adsorption was noticed.Jin the 

 case of other mixtures where tiie measurements were executed as 

 rapidly as possible, we also could not notice anything of the pheno- 

 menon. 



Notwithstanding the heating at 420° — 425° the reaction product, 

 afier the end of the ojierations, was a strongly caked but >i on fused 

 mass in which red CiioO particles were distinctly discernible. The 

 above pressures therefore relate undiiubtedly to the equilibrium 

 t)et\ve'ii the solid phases Cu^O, Cii^S, and C'lSO^. 



Wi- mii-l, ihi'i' ('nrt'. iinerl\ n'joi-i iln' ciiiclu- mi (if Schenck and 

 ,ii< .iI'.vl.M v\.\ a- 1.1 I I .1,1 M-a ail (• of a i| 1 ll|ie am 111 1 hi- .-_\ sIlmu 

 waicn waulil lie siii.iiel .1 3.10 mil -^ 'il.'iai S( ).^-| ifesMire aiid 

 waer Cii./), CnS and iJu.SO^ sUdUi.I ctex.M .1 p s.-nre ut a liquid 

 phase and a gaseous phase. Even at 430° we could /it*/ yet observe 

 the appearance of a liquid phase. 



