319 
account of which y: (1 + 7) =0,606. For pr we further find the 
value 450,1 atm. (/og'’ pr = 2,6533). By means of this we then 
find the above values of F’,,. 
Now #= 8y=12,32 is expected for the value of F at T;, 
hence M= 5,55 about. This then would be the limiting value, which 
is reached at the critical temperature. 
At 7; = 2960° abs. the ratio 7: 7, was 1,75, at 3000° abs. this 
ratio will be = 1,77. And for 7%: 7, we find 5,51. (For m, the 
value 0,181). Ete. ; 
At any rate the critical temperature of Bismuth lies in the neigh- 
bourhood of 3000° abs. with an uncertainty of perhaps a few tens 
of degrees. And the critical pressure in the neighbourhood of 450 
atm. with an uncertainty of a few units. From this it is once more 
seen how great a value the knowledge of some vapour pressures 
has for the calculation of the critical data also when as here the 
condition gradually develops from a mixture of molecules and atoms 
to nothing but atoms. For Arsenicum the critical temperature could 
likewise be fixed with a high degree of certainty at somewhat 
higher than 1300 abs. through the knowledge of the sublimation 
pressures. There at the temperatures at which the pressures were 
determined (700° a 900° abs), the condition changed still very 
little, and the value of # remained beautifully constant. 
Let us in conclusion recapitulate all that has been found in the 
following tabular survey. (p. 320). . 
At the critical point Nitrogen — N,; Phosphorus = P,; Arseni- 
cum = As,, dissociated to As, to an amount of 0,2; Sb and bi 
are = Sb, and bi, with the increased atomic attractions 88 and 85 
about, i.e. 24 units higher than the normal (residual) attractions 
7 and 9 (all this XX 10-2) in compounds. (For Arsenicum the normal 
attraction 7 is only partially increased to almost 12). 
It is still noteworthy that — where for NH, and PH, the attrac- 
tion of the central N- or P-atom is entirely eliminated by the sur- 
rounding H-atoms — the attraction of the so much larger As- and 
Sb-atoms makes itself again partially felt for AsH, and SbH,. For 
As 2,5 (normal 7) instead of 0; for Sb 4,6 (normal 9) instead of 0. 
Also for PCI,, POCI, and AsCl, diminished attractions are found, 
while we have seen in Ii that for SbCl, the attraction of Sb is 
again fully felt. / 
In conelusion we remark that for the Nitrogen group (Nitrogen itself 
excepted, unless we assume association at the triple point) the quantity 
gy, by which the ratio (v,—),): 7, at the triple point is determined, 
seems to lie in the neighbourhoud of 5 a 6. In the oxygen group 
