C 448 ) 



of equilibiinm for different degrees of concentration might then have 

 a course as represented by AXO. AiSF indicates the composition 

 of tlie liquids which find themselves in a definite equilibrium with 

 calcium h^'droxide as solid phase; litpiids with a composition on 

 A^O will coexist in definite equilibrium with solid trisaccharate. 



All this might also be deduced — and more rigorously so — by 

 first looking on the sjstem as a purely quaternary one and then to 

 proceed by a suitable way of projection to the ternary system. In 

 the quaternary system, the section of a plane indicating the inner 

 equilibrium in the liquid with the solubility surfaces of the solid 

 substances would then, when projected, give, in the ternary system, 

 the line of the definite e(iuilibrium represented here by ANO ^). 

 Meanwhile, the view stated abo\e appears to us to be satisfactory 

 and preferable, especially as it is difficult to obtain a satisfactory 

 knowledge as to the inner equilibrium in the liquid on account of 

 the complicated nature of the reaction. 



Our experiments now had their object (1) to control the compo- 

 sition of the trisaccharate; (2) to decide in how far the above view 

 agrees with the facts: (3) to determine (at least in part) the line of 

 equilibrium. 



It was obvious to fry and prove the exact formula of the tri- 

 saccharate by applying Schreinemakers' "residue method". This, 

 however, did not appear possible as we did not su(!ceed in getting 

 by subsidence or filtration a "residue" of which the content of liquid 

 phase was not very large. In order to obtain at 80° complexes which 

 consisted of solid trisaccharate and liquid, we always started from 

 solutions treated with lime at the ordinary temperature. When such 

 a solution was shaken for some time at 80° in a thermostat so as 

 to precipitate trissaccharate and then allowed to settle, it frequently 

 happened that the liquid cleared up xery well. The analysis, however, 

 always pointed out that the "residue" still contained a very large 

 quantify of the liquid phase. We have tried in different ways to 

 obtain better results, but in vain. We constructed, for instance, an 

 apparatus which rendered possible a filtration under pressure, at 

 80°, but this also led to no better result. "Residues" obtained under 

 a pressure of 5 atm. and higher had no higher content of solid 

 substance than those obtained by settling. By way of illustratioii 

 we give the results of two of these experiments in Table 1. (The 



1) Gomp. BakhuisRoozeboom and Aten, Zeitschr. f. Physik. Ghein. 53, 449 (1905) 

 also Zeitsch, f. Physik. Chem. 75, 687 (1911), wliere I have worked out a similar 

 idea for another pseudo-quaternary system. 



