888 
deration. The second critical end-point g of the pseudo-system lies 
below the melting-point of the red phosphorus. If now the tempe- 
rature of the capillary has fallen below this critical endpoint, the 
liquid has become strongly metastable, and hence at a given moment 
it will suddenly be converted to a fluid phase, from which solid 
red substance will be deposited, also there where before the colour- 
less vapour was found. 
That the solid substance formed in this way is not in internal 
equilibrium follows most clearly from this that on being rapidly 
heated it does not show the melting-point of red phosphorus, but . 
melts at a lower temperature, e.g. at 583°. As will be shown in 
a following communication, this behaviour also admits of an easy 
interpretation, just as the phenomena observed by Stock *) on sudden 
cooling of phosphorus vapour heated to different temperatures. These 
phenomena are not strange, on the contrary, they were to be expected 
in virtue of these considerations, and thus afford a not inconsiderable 
support to the theory. 
An important question which remained to be answered, was this: 
“ean it be experimentally demonstrated that in contradiction to what 
was assumed up to now the vapour pressure line of molten white 
phosphorus and that of molten red phosphorus do not belong to the 
same curve?” If the system phosphorus really belongs to the type 
ether-anthraquinone, the. vapour pressure line of molten white phos- 
phorus is not the prolongation of the vapour pressure line of molten 
red phosphorus. 
To find this out the vapour tension of molten white phosphorus 
was determined up to the temperature of 338° by means of the 
manometer of Jackson’), as has already been described by Messrs. 
SCHEFFER and TREUB *). 
Further by the aid of a new apparatus, which will be described 
later, the vapour pressure line of molten red phosphorus was 
determined, in which it appeared that the triple point pressure of 
red phosporus amounts to almost 50 atmospheres. To answer the 
question proposed above the vapour tension, which the liquid white 
phosphorus would possess at the triple point temperature of the red 
phosphorus (610°), was calculated from the observations by the aid 
of the integrated relation: 
a b 
1) Ber. 45, 1514 (1912). 
2) J. Chem. Soc. 99, 1066 (1911). 
3) Verslag Kon. Akad. v. Wet. 25 Nov. 1911, 529. 
Zeitschr. f. phys. chem. 81, 308 (1912). 
