B8 ) 



\ si nee may be studied l\v the aid o\' t l»o U'->urfaee for the unity 

 of weight in the same waj as by the aid i»t' ihal for tlie molecular 

 quantity ■ moreover ii is easj to pass from the former to the latter, 

 which oflers advantages for the treatment i>( many problems ef. § 6 

 if this is desired. 



rhe equation of the spinodal curve on the Surface for the unity 



of weight of mixtures, for which Van drr Waals' equation of state 



for binary mixtures with a and b not depending on v and 7*for constant 



ipplied, and for which I ..-.= ,/\i.i/+^*,V 



m. No 96 . Dec '06, p 510 ma\ be put, 1 ) runs: 



R, R, IV = 2 «,(1-») i I - -/•' l : , l 



Here /.' and h\ are the gas constants for the unity of weight of 

 the components concerned. For \. = this equation passes into 



l> IS 



4W =(l-*)[{3« -(I- - '1 



r • . ■ i 



put = - - = o». The roots ot tins equation in id have 



been determined by a graphical way for definite values of and t. 

 The figure has been construed for mixtures for which R, R, = s . 

 no \ 96 . Febr. '07, p 600, footnote - 

 With reference to Fig. I we point out that tor < ,(=1.299 

 and *> /"; a spinodal curve closed on the side of the ii singr's 

 and together with - .nilar plait, extends on the ^-surface from 



the side of the small ■:•">. At T= ï\ this plait reaches the side oi 

 the least volatile component At lower T the spinodal curve has 

 s .net branches, and the plait runs in a slanting direction from 

 the line r = b to the side ot* the least volatile component 



Thus the inves _.. m ot* mixtures with a g s rithout cohesion 



calls attention to a plait that starts from the side of the small volumes. 



and er temperature runs in an oblique direction to the side 



ie tigure. which plait can be distinguished from the transverse 



. from tl -tudinal plait. 



The spinodal curve for r = 1.0J as a arotropk plait point /'.. 

 Fig. 1 For 1 299 <C*< 1.040 the angle with the p-axis 



the tangent to the plait in the plaitpoint *) h .. > -. forl.040<T<l 



- ~ ^ The barotropic phenomena foi su .1 be further 



The quantities a : .... &u, b i: relate to the ur. 



.:..*. ti^jr etc to the molecular quantity. 



