1684 
AV<0 and Ay>0 [series { and 4). We obtain the same P,7- 
diagram as in fig. 2, again with this great difference however, that 
we have to change mutually the stable and metastable parts of 
the curves in fig. 2. 
In the four P,7-diagrams which we have deduced now, all 
curves, which belong to a same group [viz. group A, R, Ba, Bo, 
S, C and T| always go in the same direction of pressure and 
temperature. The curves of group A go, viz. starting from the in- 
variant point in fig. 1 all towards lower P and higher 7, in fig. 2 
all towards lower P and 7’; the curves of group & go in fig. 1 
viz. all towards higher P and lower 7, in fig. 2 towards higher P 
and 7’, ete. It appears from table 1 why this must be the case. 
As the groups C, Rk, and S in each of the P,7-diagrams form 
each a bundle of curves, the above mentioned is also true for those 
bundles of curves. 
This is however no more the case for the bundles of curves A + 7 
and B= B, + by; the curves of bundle A + 7’ all go in the same 
direction of temperature, but not in the same direction of pressure, the 
curves of bundle B = B, + B, all go in the same direction of pressure, 
but not in the same direction of temperature. We call such bundles 
“divergent”; bundle A + 7’ is then divergent in direction of pressure, 
bundle B, + Bi in direction of temperature; in fig. 3 bundle A + 7 
is divergent in both directions. We shall examine further under 
which conditions a similar divergency of a bundle may occur. 
Deducing series of signs (20) from, (19) we have assumed that in 
(14) w,...™,—1 is positive and p,...u,+2 negative; in the two 
series the phases /’.../,,; have, therefore, the same sign and 
the phases F,.../,4.2 therefore the opposite sign. Further we have 
assumed that the phase /’, is situated in group 5; for this we have 
divided this group into the two groups B, and B. 
It may, however, also be the case that the phase /’, is the 
first of a group in the series of signs (19), consequently also in 
series a of table 1. We shall assume that it is the first of group S. 
Then in table 1 we need no more divide group 4 into the sub- 
groups B, and Bj, for the whole group B obtains then in all series 
of table 1 the same sign as group B,. The two arrows in line / 
of table 1 must then reach the vertical line, which separates the 
B and S from one another. 
Now we obtain again four /?, 7-diagrams, which we may represent 
by the figs. 1 and 2 and by two other figures which we obtain when 
we mutually change the stable and metastable parts of the curves in 
