( 235 ) 



Already in a previous paper (These Proceedings Jnne 27 1903} I 

 had elaborately demonstrated this, and somewhat later (These Proceed- 

 ings 31 Oct. J 903) KuENEN arrived at the same opinion independently 

 of me. ') And in 1900 Schreinemakers (Z. f. Ph. Ch. 35,p. 462—470) 

 had experimentally demonstrated that one maximum leaves the 

 longitudinal plait for exactly the same mixture (phenol and v^^ater), 

 for which van der Lee thought he could theoretically prove, that 



Finally I shall just point out that in the peculiar shape of the 

 p, T-diagram of the plaitpoint line (tig. 7) in the neighbourhood of 

 the point D, and in the fact that the two critical moments represented 

 by figs. 4« and 4'^ (as B and Al in general do not coincide) do not 

 coincide, the clue may be found for the explanation of a highly 

 puzzling and as yet unexplained phenomenon, which has been observed 

 as well by Guthrie as by Rothmund [Z. f. Ph. Ch. 26, p. 446 

 (1898)] ') in their experiments, viz. the appearance and disappearance 

 of a distinct cloudiness when the mixture is heated above the 

 "critical temperature of mixing", which cloudiness often continued 

 to exist up to lO"" above this temperature. 



1) G. f. also KuENEN : Theorie der Verdampfung und Verfliissigung von Gemischen. 

 Leipzig 1906, p. 170, note. 



••2) For the rest the assumption .'C3=.Xi,2 at the point M leads, as the calcula- 

 tions teach, not only to strange, but to highly absurd conclusions. 



3) G. f. also Friedlander, Ueber merkwiirdige Erscbeinungen in der Umgebung 

 des kritiscben Punktes. Z. f. Ph. Gh. 38, p. 385 (1901). 



(October 25, 1906). 



