( 102 ) 



as a function of the concentration is represented by a similar curve 

 as that representing the potential values of mixtures of two liquids. 

 The problem therefore is to find out what cases may present them- 

 selves when these two curves are made to alter their relative 

 positions, in passing from higher temperatures to lower. 



The result of this investigation is, that where a continuous mixture- 

 series exists, three cases are possible. 



Case 1. The congealing points of mixtures of liquids of the 

 substances A and B, fall gradually from the congealing point of 

 B to that 0Ï A, in proportion as the composition of the fused liquid 

 is shifted in the direction of A. (in case of B's being the substance 

 having the highest fusing-point). 



Case 2. The line of the congealing points shows a maximum. 



Case 3, The line of the congealing points shows a minimum. 



In all the three cases there is the following connection between 

 the concentration of the fused and the solid mixtures: 



The solid mixture contains, in comparison to the fused, a higher 

 percentage of that ingredient, at the increase of which the congealing- 

 temperature rises. In the maximum and in the minimum the two 

 concentrations are equal. 



Important conclusions for the process of congealing and fusing 

 and for the fractionation of mixed crystals may be deducted from this. 



If the mixture-series in the solid state is not continuous, it may 

 be deducted that two cases are possible. 



Case 4. The line of the congealing points shows a break in a 

 transition temperature, situated between the fusing points of the 

 two components. At this point occurs a hiatus in the composition 

 of the mixed crystals. 



Case 5. The line of the congealing points shows two descending 

 branches, meeting in a minimum point, below which temperature 

 every fusion congeals to a conglomerate of mixed crystals with two 

 different concentrations. 



There may still appear further complications, should there exist 

 more than one solid modification in either of the components or 

 in both. Following the same lines that have led to the discovery 

 of the connection between temperature, concentration of solid mixture 

 and concentration of liquid, it is equally possible to find in what 

 manner the transition takes place from one solid state into the 

 other with different mixing-proportions both in case of homogeneous 

 and non-homogeneous mixtures. The number of peculiar cases is 

 here extraordinary, owing to the fact that in both components the 

 corresponding coaditions may follow each other in dillereat uiauners 



