114 



place tlie peculiar way in which, as Stock and GomolKa ') were the 

 first to fiJid, red phosphorus can snddenlj deposit from snpercooled 

 molten violet phosphorus and its vapour, seemed to point to a cri- 

 tical phenomenon. 



In virtue of tliese three circumstances which seem to he in agree- 

 ment with each other, we concluded phosphorus and cyanogen to be 

 systems of the same type, and devised a diagram for the i)seudo 

 system of phosphorus, which was in close connection of I hat of 

 cyanogen. 



Now for the first time the question raised by Bakhuis Roozeboom, 

 has been answered, and it has now appeared that the three above 

 mentioned circumstances misled us at first. Phosphorus does not 

 belong to the same type as cyanogen and the liquid white phosphorus 

 must be really taken as supercooled liquid violet pjhosphorus. 



The first determinations of the vapour tension were faulty at the 

 highest temperature. Aston and Ramsay's determinations of the surface 

 tension of liquid white pho.sphorus (which were only two, indeed) 

 appear not to justify a calculation of the critical temperature, and 

 the just mentioned phenomenon, which was observed by Stock and 

 GoMOLKA, must l)e ascribed to this that the number of nuclei posses- 

 ses a strongly pronounced maximum at a definite degree of super- 

 cooling, so that a spontaneous crystallisation, which proceeds with 

 \ery great velocity, suddenly occurs there. 



We see with great satisfaction that the system phosphorus can 

 be represented in a simpler way than we thought at first in con- 

 sequence of the non-existence of the supposed complication. 



The P, T'-projection of the system phosphorus for so far as it is 

 known now, is schematically represented in the subjoined fig. 6. 



589°S B9S' 



Fis. 4. 



1) Ber. 42, 4510 (1Ö09J. 



