( 638 ) 
The region in which these mixtures exist does not however extend 
below the line HG. For in E the transformation takes place of 
pure azoxyanisol from A, to As. In the mixed crystals this tempe- 
rature is lowered in an increasing degree with the concentration of 
hydroquinone; this causes the fall of the line HG. From the liquid 
mixed crystals, azoxyanisol is separated in the ordinary solid con- 
dition A, by cooling below FG ; the remaining mixed crystals succes- 
sively move towards the point G. This, however, is the lowest point 
of the triangle CEG within which mixed crystals are possible. 
At this temperature, 111.6°, they already exist in presence of solid 
A, and can also exist in presence of the liquid H. As below the line 
FGH, solid A, can only exist with liquids HK, the mixed crystal 
G must, on further cooling, be transformed into solid A, and liquid 
H; this indeed happens. The phenomenon is the most striking if one 
starts from a concentration corresponding with G. The formation of 
liquid mixed crystals then takes place from g to G and on further 
cooling the transformation: liquid crystal G — solid # + liquid H 
immediately takes place. The liquid again appears, not however G 
but H, therefore of modified concentration and also in a more limited 
degree because some solid As is deposited at the same time. 
The relation of liquid to solid is as FG: GH and as G and 7 
respectively belong to. 8.75 and 10 mol. °/, of hydroquinone the cal- 
culation shows that 87 °/, by weight of the total mass returns to 
the state of liquid 4. The phenomenon is the more striking because 
the formation of the liquid crystals from g—G@ took place within a 
small temperature-interval (3.5°). The great ease with which mixed 
crystals undergo change when in the liquid crystalline condition 
renders it probable that the phenomenon will often present itself 
with mixtures in which substances of this kind occur. 
A condition is, of course, that the line ZG must intersect the line 
CG, or expressed in the language of the theory of the dilute solutions, 
that the depression of the melting point C by the admixture of the 
second substance, is sufficiently larger than the depression of the 
transition point Z. Since, as far as is known, the heat of transform- 
ation at C is many times smaller than that at Z (about 40 times 
in the case of azoxyanisol), therefore the molecular depression 
0.02 7? 
Z 
in which g represents that heat, will be much greater for point C 
than for point i, even when taking into consideration that in the 
calculation the concentration GH must be taken in the first and FH 
