Ty, = 125°,96 abs. (K.O., Dorsman and Horst, who also determined 
the critical pressure): 
D, = 90,8681 + 0,3110 X 1,586 (0,5193—0,5006) = 0,8697. 
From this follows A: D, =—16,11, hence v, = 71,88 . 10-5. 
For the factor f, = 6%: v, we find further: 
1,793 
We therefore calculate 88,8.10 5 for bj, while 86. 10-? was 
found directly from 7), and pz. 
Finally we have for the product fu, : 
Fw, == 1,235 X 1,998 = 2,47. 
J, = 1,586 1 - Ma 0,506 | = SBO (10,291) — 1,205. 
b. Phosphorus. From the approximate formula the value 2,182 
follows for 2y from 7; = 968° abs., so that 7 becomes — 1,091. 
With 7), = 44°,1 C. = 317,2 abs. for the yellow phosphorus (Smits 
and pr Leeuw, 1911) we find therefore (m, being == 0,3277): 
1,091 
A= 2,182 1 -- 
; 2,091 
+ et 
x 0,327 | — 2,182(1 — 0,171) = 1,809. 
All this refers to the yellow (white) phosphorus, which according 
to Smits ¢.s. is a metastable continnation of the liquid phosphorus 
below 589°,5 (the melting point of the red phosphorus). As this 
latter point lies too high for the caleulation (the vapour pressure is 
there already 43,1 atm.), and the density D, is perfectly unknown 
there, we have chosen the melting point of the yellow phosphorus 
as starting point. 
For the density of the yellow phosphorus 1,82 has been found 
at O° C. (Jorrsors, 1910); hence D, = 1,79 will be found at 44° 
with the (linear) coefficient of expansion 0,0001278 (between 16° and 
42° C. according to Kore). Therefore A: D, becomes = 17,34 and 
v, = 177,37.10-5. We find therefore 140,0. 105 for bj, while the 
_value 134.10—° has been found from 7%, and p‚, and the theoretical 
’ value amounts to 140.10-°. 
The product fu, becomes for the yellow phosphorus : 
fu, = 1,809 x 3,053 — 5,52. 
For the red phosphorus, where u, = 968,1 : 862,6 = 1,122 and 
m, =—0,8913, therefore f, = 2,182 (1—0,465) =1,167, f,u, becomes : 
fu, = 1,167 X 1,122 = 1,31. 
There exists therefore a great difference in these values for the 
two phosphorus modifications, which is chiefly caused by the different 
molecular state at the two triple points. Really a higher degree of 
polymerisation is assigned to the red phosphorus than to the yellow 
20* 
