( 610 ) 



at about ± 8° the point i\ arrives on the side A WAm, so that 

 above this temperature a separation of water-aleohol-ammonium 

 sulphate may occur in the ternary system. 



I have further closely investigated at 30° the equilibria occurring 

 in this quaternary system ; the results are represented by the schematic 

 figure 2. 



The saturation surface Am which at 6°. 5 still consists of a coherent 

 whole, now consists (experimentally) of two parts separated from 

 each other: this is because the binodal surface L X L^ now terminates 

 on the side plane A WAm in the curve rt,£y/,. 



L 



Fig. 2. 



Of the critical line k x k t the terminal point k r represents a ternary 

 critical liquid; all other liquids of this line are quaternary critical 

 ones, of which k t is saturated with solid lithium ammonium sulphate. 



The phenomenon of the existence of a second heterogeneous region 

 at this temperature was quite unexpected ; it is represented in the 

 figure by the binodal surface L x l L % 1 or d x k t d t k % with the critical line 

 k t k t . I have not further investigated at what temperature this is 

 formed; it is sure to be present at about 18°. 



