1325 
1 
At the left of and above a"DSd" is situated the region F4 PF 
3 » neh); below wtp ns - nl ne RG 
en pak on en ee et » » FLAG 
BIS eee ee eI 8 x “a pike sE 
These regions are, therefore, situated, with regard to the curve 
a" DSd', in the same manner as in fig. 1. It is also evident there- 
from that in the P,7-diagram the regions /” + G, #’ + + Gand 
F’ + L are wanting. 
In order to survey the connection of these regions we might draw 
a representation in space by now also placing perpendicularly to 
fig. 1 the composition of the complex / + #”. From this spacial 
representation we might then deduce the pressure concentration the 
temperature concentration and the P, 7-diagrams for definite concentra- 
tions. We will, however, not go into this matter any further just now. 
3. Some other cases. 
Up to now, we have supposed that # and #’ melt with increase 
in volume and that this is also the case with the congruent and 
incongruent melting of the complex F+ #”; in agreement there- 
with, the temperature on each of the three melting point curves in 
fig. 1 increases with elevation of pressure. 
We now see at once that there are many cases to be distinguished; 
the reader himself can easily introduce the necessary alterations. 
Further, we have supposed sub 1 that in each point of the curve 
a"DSd' occurs a congruent reaction and sub 2 that in each point 
of this curve an incongruent reaction appears. It is evident that in 
this respect also many cases may be distinguished of which I will 
briefly mention a few. 
We imagine on the sublimationcurve a point /; on the part al 
occurs, between the phases of the complex #4 4’ + G, the con- 
gruent reaction #” +4 F2G; on. the part 7D the incongruent 
reaction /” 2 F+G. In the point 7 itself the compound / will 
then take no part in the reaction but the reaction /”= G takes place 
in which G has the same composition as F”. 
Hence, in the point / occurs the complex “+ /” + vapour F’; 
in 7 therefore, also exists the complex /” + vapour /”. From this 
follows that / is not only a point of the sublimation curve aD but 
also of the sublimation curve a’K’. 
Now, the direction of these curves in each point, therefore also 
; : [aE HLSW, 4 : 
in lis determined by 7 ape As, however in the point / the 
reaction in the two systems #’-+ #” + vapour #” and /” + vapour 
