( hm ) 



known, or rather iiixcslijiatoii, wliirli liolonp to Tvjie J, ho\\\ follow 

 tlie rule derived. 



Witli C,H, + CH,OH 6» is viz. i,(i9, .t = 1,(33, so on aeeount 

 of ::r = <9, .i\ cannot be >,Ci. And with SO, + H,0, 6» = 1,49, 

 jr = 2,47, i/jr ^ 1,57, hence the second member of (5) ^ 1,15. And 

 1,49 is 'not <[ 1,15, so ;v, is also not >.*'i. Thi.s implies again that 

 no naininunn critical temperature is found. 



So the fact that of the four mixtures C,H, -f CH,OH,, C.,H„ + H,0, 

 SO, + H5O and ether -[- H.,0 only the last has a three phase 

 pressure greater than the vapour pressures of the two components, 

 is in perfect harmony with (he theoretical derivations given above. 



3. Let us now briefly discuss the third point, viz. the connodal 

 relations. As we are guided by the different figures of the adjoined 

 plate, a few words will suffice. The essential part was already given 

 by me in a few suggestions in one of my last papers (loc. cit. 

 p. 37 at the foot and p. 38 at the top; p. 44 at the foot and p. 45 

 at the top ; p. 48 in the middle), where I referred (0 Kortp:wko's 

 well-known papers, with regard to the neighbourhood of the points 

 R^ and R^, and to some papers by van der Waals, with regard to 

 the points R,^ and R', with the third principal type. 



Now we may add to this, tiiat recently van der Waals [in the 

 Proceedings of the same Meeting as in which my first paper on the 

 spinodal and the plaitpoint lines was published (Meeting of March 25 

 1905)] has given an addition to his former considerations concerning 

 the just mentioned third type, in agreement ^vith what Korteweg 

 derived for this case already 14 years ago (loc. cit. p. 316 — 318, 

 figs. 30 — 35). We have reproduced this course of transformation in 

 our figs. 9, 10 and 11, l»ut now in connection with our former 

 considerations on the course of (he plaitpoint line. So also in 

 other cases. 



a. Principal type I (figs. 1 — 6). 



In fig. 1 we see the gradual transformation of the principal 



(transverse) plait, when the temperature falls from t = — := 2,37 





 at 6', to 0,80. (These numerical values relate to special case h^r=b^, 



but when ^1 ^ ?>, the relations are modified only numerically, as I 



have demonstrated in the above cited paper in the Arch. Teyler). 



T 

 1\ is the temperatui-e of the point t\, and is put =r 1. Ö = ~? 



