574 



In the side plane for «-anhydride -j- (^-anhydride we only know 

 the meltings point /; and b' of « and /^-anhydride, it being assumed 

 here that there occurs a eutectic point (point (/"). 



The melting surfaces in the space are clearly visible in the spacial 

 figure. At the place where the melting surfaces or solubility surfaces 

 intersect, there arises a three-phase line, and at the place where 

 these three-phase lines meet — and this meeting always takes place 

 by three three-phase lines at the same time — there arises a 

 quadruple point. 



Two quadruple points may be pointed out here in our spacial 

 figure, first the point c' lying above 93°,5, where coexist: 



^^aq -\- S^. -\- Sli -\- L 



and secondly the ternary eutectic point e, where coexist: 



I '^«09 + '^;3 + '^H^O + L 



lying according to the calculation at — 2,6°. 



The 7, x-spaciaJ jigure of the binary system. 



In the ternary pseudo figure described here lies the binary sj'Stem. 

 We get this system, when we draw the surface of equilibrium 

 for the equilibrium ft'ï^^ in aqueous solution at different total con- 

 centrations and different temperatures through the axis for the 

 component H^O. 



This surface of equilibrium intersects the melting point surface 

 of t?-anhydride along the line tin, from which it follows that in 

 the binary system water-niilksugar the saturate solutions in stable 

 state coexist with /^-anhydride from m to /. A change sets in in this 

 in the point m, for below this point the equilibrium surface does 

 not intersect the melting point surface of /3-anhydride, but the 

 melting point surface of «„^, so that it is clear from this that the 

 point m represents the found remarkable transition dehydration 

 point lying at 93°,5, and for which on supply of heat the trans- 

 formation 



Sa —^ Si A- L 



aq ' 



takes place. 



Further the said surface of equilibrium of course intersects also 

 the ice-plane, and the line of intersection here indicates the melting 

 point line of the ice in the binary system. This melting point line 

 of the ice and the melting point line of tlie hydrate intersect in n 

 (at 0,65° and ± 0,6 mol. "/o)» vvhere the surface of equilibrium meets 

 the eutectic line de of the pseudo-ternary system. 



