928 
My = U = Mp2 = U 
then (2) passes into: ‘ 
ua, +... + ua), + ua Pom + My 42 aot se ve 0-8 
In order to find the reaction between the phases of the equili- 
brium (f,), we have to eliminate #, from (1) and (4); with this 
net only /, disappears, but also #4; and Ms. Consequently we 
do not get a reaction between n+ 1 phases, but between the 
n—1 phases 
FF Dip 4 Prest TD: 
For the reaction between the phases of the equilibria (/,41) and 
(42) we find the same relation between those n—1 phases. In 
each of the other reaction-equations for the monovariant equilibria, 
however, n + 1 phases occur. 
The phases 4, F4 and Hp are, therefore, the indifferent phases, 
the n—1 other phases are the singular ones. 
We now have four singular equilibria, viz. : 
M= EH... Bia + Pps + + Ens 
Lj) = WD) + Fin + Fe 
(Poi) = (M1) + Fy + Foe 
and 
B) = UM) + F, + Bays: 
The three indifferent phases may have in (1) the same sign or 
not. (In the first case + + + or — — —, in the second case, 
EE 
as in Comm. X we are able to show now: when in a reaction- 
equation two indifferent phases have the same (or opposite) sign, 
then they have also in all other reaction-equations the same (or 
opposite) sign. 
Just as in Comm. X we are able to show: when the three indif- 
ferent phases have the same sign, then the singnlar equilibrium M 
is transformable, when they have not the same sign, then the equi- 
librium (J/) is not transformable. 
In the same way as in Comm. X it now follows: 
1. The three indifferent pbases have the same sign or in other 
words? the singular equilibrium J/ is transformable. Curve (M) is 
monodirectionable; the four singular curves coincide in the same 
direction. 
2. The three indifferent phases have not the same sign or in 
other words the singular equilibrium J/ is not transformable. 
Curve (M) is bidirectionable; of the 3 other singular curves, 2 cur- 
