( 139 ) 
In the point S — can even become positive, viz. when — A V 
' dT 
becomes negative. This is e.g. the case when — Ah has only a slight 
positive value, so that in (17) the term with 
begins to prevail for higher values of T; in other words: when the 
sign of v — v f is no longer only given by the sign of h — b' . In 
this case the line SM runs as indicated in fig. 7; i.e. with a ver¬ 
tical tangent in A, where — A V changes from positive to negative. 
Of course this point A may lie at very high pressure, so that it 
seems that the line SM continues to run to the right (which will 
of course only be the case for Ah positive). 
16. It follows from the expression (10) of II p. 35, viz. 
< r =°) * = 
which we have already discussed there, that for small values of q a 
p 0 (the part ON at T— 0) may become even 0 and negative. We 
shall then have a course as indicated in the figures 8—11. 
The solid region contracts more and more, when p 0 decreases. At 
the same time the triple point & will move more and more to the 
absolute zero point 0. 
As soon as p 0 has become negative (fig. 9), there appear necessarily 
two triple points S and S', as the realisable pressure of coexistence 
remains, of course, positive. So* with sufficient lowering of the tem¬ 
perature (the pressure remaining between that of M and S), we get 
first into the solid region, but finally again into the liquid region. 
The possibility of such a course has already been suggested by 
Tammann (see inter alia Bakhuis Roozeboom, “die heterogenen Gleich- 
gewichte” I p. 83, fig. 9) — with this important difference however, 
that Tammann supposes, besides a vertical tangent in A (see our fig, 7) 
and a horizontal one in M, another vertical tangent in A and a 
horizontal one in M' (see fig. 12). Such a course, however, is 
so a finite negative value; whereas in reality the last limiting value is = + qo . 
But this error has had no further influence on what follows, as (12a) and (13) 
have no more been used. 
That at first the value of p itself at T — 0 is increasing, appears from 
q. - (p + A) (-A4) = aT + fiTlogT, 
which is decreasing for T = 0, while vv’ then remains unchanged. 
1+ * 1+f 1 
L p+%* p+*i +J 
10* 
