( 464 ) 

 25 + 2^^' + ^^ (2/-3x')'>,V"- l(27'-3;.>"-3yVÏ-f 9(/-x')r".."- 



4- (3y'-2x>/',.-" + 4.7„|.;" + 4 V" = ^ (88) 



4 



FiiiiliiT ri'dnction of tlw third ron/iodd/ n'hifion. 

 Derlvdüon of equation (25) of the frst (.lescriptlve part. 



26. Hv addition of (85) and (88) wc find: ') 

 9 9 97 03 



4-|-(2y'-3xV'|-|-|^f(2y'-3x')M 10(8y'-2x')h^-'' = 0. . . (89) 



When we add to liiis relalion (72), wliieli is (Icdiiced from tlio 

 second connodal relation, after having multiplied it with r", we can 

 divide by if' and we get: 



1 ^' - 1 v" + !^^ iMKv'-^'}i + 32 '^^^'"^'''^' "" 10(3/-2x')l.''' = . (90) 

 Making use of (69) we may solve tlie (piantity r" from this equation : 



t'" = 2«' + 4- n' + -~ [(2y'-3xr-24(2y'-3x') (y'-x') + 10 (3y'-2>c')l.." , (91, 

 o o 



or finally with the aid of (73): 

 18 . I 7 



"=- t' + }^ [(2y' - 3xr - 8 (y— /)J -f 



+ Y [(-y - ^"^y - --^ ^-V' - -^y-') (y' -'<') + 1 ^> ('V - 2x')l j /' . (92) 



from which erpuitioii (25) follows immediately with tlio aid of (65) 

 and (26). 



In this way we have found tho sfai'tiug-poiiit of the curve in the 

 (r, -r)-diagTam described by the |)oint halfway between the points 

 which represent coexisting phases. The tangent in that startijig point 

 also is now known. 



1) Remarkable is the disappearance of tlie terms derived from zo x-, which makes 



On bo 



also ).' and ff, i. e. " and ~ disappear from the result. We have tested the truth 

 «1 ^1 



of this in different ways. 



