365 
sequence of the partially metastable, partially unstable middle portion 
of the melting-point line of the pseudo-component 5 no longer 
intersecting the metastable unary liquid line, but running round this 
curve. And the lower point of solidification may be absent, when the 
same curve lies entirely above the metastable prolongation of the 
melting-point line of the pseudo-component A. 
When the question is considered in what way in case of liquid 
monotropy, the metastable phase can be obtained from the stable 
one, one arrives at the conclusion that this will have to take place 
by rapid condensation of the vapour, which in concentration is nearer 
the metastable than the stable liquid. 
Whether substances have already been found which belong to the 
above-described type, is still open to doubt, though in the literature 
statements are found, which might lead us to suppose so. 
As is known, it was believed for a long time that the pseudo- 
system of sulphur had to possess a region of unmixing, because it 
was thought that some phenomena observed in the investigation 
furnished indubitable indications in this direction. This view was 
first pronounced by Baknuis Roozesoom, and supported by Krurr, 
on the ground of his own observations). After SmitH c¢.s.”) had 
made it probable that the quasi-unmixing was to be ascribed to a 
difference of temperature, | succeeded last year in conjunction with 
Dr. ve Leeuw ®) in ascertaining with perfect certainty that the phenome- 
non in question has nothing to do with a phenomenon of unmixing, 
and is really brought about by a difference of temperature, which 
gives rise to a quasi-unmixing when tubes with more than a certain 
inner diameter are used. 
Moreover it appeared that the point of solidification of states of 
sulphur fixed at higher temperatures could not give support to the 
old view, so that not a single reliable experimental datum is now 
known that speaks in favour of the existence of a region of incom- 
plete miscibility in the pseudo-system. 
That the shape of the line for the stable unary liquid equilibrium 
resembles that of the line £Z in Fig. 5, is of course, of not the 
slightest importance, for also when the pseudo system possesses no 
region of incomplete miscibility in the liquid state, ‘the said line can 
have such a shape. Besides, the system sulphur, as I already stated, 
is at least pseudo-ternary, which view is in harmony with the 
1) Z. f. phys. Chem. 64, 513 (1908). 
Rn x » 57, 685 (1907). 
5) These Proc, Oct. OLE, pr 461: 
