( 169 ) 



We shall now investigate when they also disappear. Apparently 

 this is the case, when the snmmits P' and Q' , R' and S' lie at 

 7=0; i.e. when these points coincide with .0' and ^4'. These snmmits 

 are determined by the equations (6), in connection with T^^cj^ [^ .v{l — .v). 

 Now P' coincides with B and Q' with /I, if these equations are satis- 

 fied by T=0, .)' — (), .i' =1. It is clear that this requires ^^ = 1. 

 F'urther R' coincides wilh A' and S' with />', if the equations are 

 satisfied by T =: 0, .c = l, x'=:0. And this can only be the 



case when ,i' = — , in our case /3' = - = 0,8333. 



'I. '^ 



Vlll. It is easy to see that the results of the ai)()vc investig-ation 

 would remain unchanged (lualitatlvely , if we had not neglected the 

 quantity r in the term at'% and if we had not omitted the quantity /? for 

 the liquid phase by the side of the corresponding quantity |3' Q? being 

 nearly always very small compared witli |i'). Then all the values given 

 for i^ , X, x' and T would be slighth" changed numerically, but the 

 transformations and transitions which we have discussed, would have 

 occurred in the same order and exactly in the same way as we have 

 described above. 



We conclude from the above considerations, that the occurrence 

 of a eiitectlc point and the apparent interruption in the series of 

 the solid mixtures caused by it, necessarily follow from the theory 

 represented by the equations (2) or (6), which teaches that high values 

 of ii' (or a'), i. e. of the heat required for the mixing of the solid 

 piiase, cause the occurrence of unstable conditions. In reality the 

 curve is coiituinoiis, as is shown u\ the dilfei-eut figures, but in 

 general only a part of the continuous meltingpoint-curve is liable 

 to be realized. And only this part of course is found by means of 

 the experiments. 



Finally I regai'd it as an agreeable duty to cx|)ress my thanks to 

 Prof. Bakhuis Roozeboom, who has encouraged me to undertake this 

 investigation, and \vlio has given me many a useful hint also for 

 my former papers on the meltingpoinl-curves of amalgams and 

 alloys. 



(August 27, 1903). 



