( 446 ) 



or in solution a line AB niiglit indicate the solubility at 80° of 

 calcium hydroxide in sugar solutions of varying concentrations ^). 

 If there were no molecules of calcium hydroxide in the complex a 

 line like DE would indicate the concentration at 80° of the trisac- 

 charate in sugar solutions of different concentrations. That this line 

 is situated at higher lime concentrations than the first line is probable, 

 but not certain. If now we start from a complex P, and assume 

 that this consists of a liquid of the concentration H and a solid, 

 phase 'f we can trace what will happen if, in the solution H, 

 the molecules of trisaccharate present are being converted into 

 calcium hydroxide and saccharate. The concentration of the molecules 

 of the trisaccharate then begins to decrease, causing the equilibrium 

 between the solution and the solid phase to be disturbed ; this 

 phase-equilibrium will endeavour to restore itself. 



Let us now suppose (and this supposition governs the whole argu- 

 ment) that (he equilibriuui of phases sets in more rapidly than the 

 inner reaction-equilibrium in the liquid, then the following will 

 happen iu the process of the decomposition of the trisaccharate. In the 

 solution iu which molecules of trisaccharïite are being decomposed, 

 fresh quantities of the solid phase will dissolve. The composition of 

 the liquid will now be represented b}^ a point which moves along 

 the line i/7' in the direction of /. This will continue until in the 

 solution so many mols. of calcium hydroxide have formed that this 

 is on the point of precipitating. If this happens, for instance, in the 

 point /, the composition (or to be more correct, the point indicating 

 the same) will move along a line which does not coincide with the 

 prolongation of the line HI, but intersects this in /. This eutectic 

 line, wiiich indicates the composition of the liquids which are in 

 phase-equilibrium with the two solid substances, trisaccharate and 

 calcium hydroxide will have a course like the line IL, and in any 

 case be situated to the left of IT, because the Ca 0-content is less 

 than that of the liquids to which the line 12' relates. Whereas on 

 further decomposition of the trisaccharate the composition of the 

 liquid will, therefore, move along the line IL, the average composition 

 of the solid phases will move along the line TA" from J" towards /v. 

 When the composition of the liquid has arrived in L and, simulta- 

 neously, that of the solid phase in K, all the solid trisaccharate 



') It is almost superfluous to point out that, for the sake of clearness, the 

 solubility of the lime has been drawn far too large. For the same reason the 

 figure has been drawn complete although little or nothing is known about the 

 behaviour of the components and eventually occurring compounds at very high 

 sugar concentrations. 



