H71 



by crosses. At temperatures helow the (|iiadruple point a compound 

 again occnis, which has also already been ol)seived by Dittk, and 

 which according to him consisis of equal molecular (piantities of 

 o-toluidine and carbonic acid. 1 myself have not determined the 

 concentration of this compound; the ap|)lication of the above de- 

 scribed method of analysis is accompanied with pretty great diffi- 

 culties at the low teinperatuies. The possibility that the solid substance 

 should be pure o-toluidiiie is excluded, because the quadi'uple point lies 

 at higher temperature than the melting-point of the pure substance. 

 (Of. table 5). 



5. I'he system m-toluidine-carbonic acid, the m-tolyl carhaminic-acid. 



There occurs a quadruple point SLjLjG in the system m-toluidine- 

 carbonic acid at a temperature which lies between that of o-toluidine- 

 carbonic acid and that of aniline-carbonic acid. The three-phase lines 

 have again the same relative situation as was described above. The 

 observations referring to the three-phase lines LjL^G, SL^G and 

 S]i,G are recorded in table 3 and indicated in figure 2 by triangles. 

 In this tigure are also fownd the vapour tensions of pure carbonic 

 acid (see table 1). 



6. The analysis of the compound according to the method 



TABLE 3. 



7. '5 

 10.0 

 13.2 

 15.5 

 18.0 

 20.9 

 23.9 

 27.35 

 30.3 

 33.7 

 35.85 

 37.2 



40.5 

 43.1 

 46.4 

 49.2 

 52.1 

 55.7 

 59.5 

 64.2 

 68.5 

 73.8 

 77.4 

 79.6 



Quadruple point 



6.30 



39.2 atm. 



