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lY. TIic sijslcin HodiiiHisiiljale^ cl/ii/lalcohul (did iratcr. 



In this system Mr. UE Bkuijn 

 investigated besides the stable 

 equilibriums also some less stable 

 ones. Fig. 3 indicates the gene- 

 ral form of the isothermals below 

 32°5 ; the drawn curves RS and 

 SQ show the stable equilibriums, 

 the dotted curves LU and MN 

 the less stable ones. KS indicates 

 the solutions that can be in equi- 

 librium with solid NaoSOilOlIoO; SQ the solutions in equilibrium 

 witii Naj, ÖO4.S is the solution in equilibrium with Nai;S04 lOlIoO 

 and Na2S04. At a rise in the tem|jerature the point S moves to the 

 left and upwards and at 32°.") joins R in V, this point indicating 

 the composition of the aqueous solution that can be in equilibrium 

 with solid Na£S04 lOHjO and NaoÖÜ4. When the temperature rises, 

 the line RS therefore dwindles, while St^ is prolonged ; at 32°5 

 RS disappears and only SQ is left, while S falls on the line WZ. 

 Mr. DE Bruijn has determined these isothermals for different tempe- 

 ratures experimentally. 



Besides the stable equilibriums mentioned above viz. Na2S*)4 lUlfJ) 

 4- solution and Nao SO4 + solution Mr. de Buuijn also determined 

 the less stable system Na2 SO4 7 HgO + solution. The solutions 

 in equilibrium with the hydrate Nag SO4 7 HjO are represented by 

 line LU (fig. 3). The latter being situated entirely above the curve 

 RS, the solutions pass into a solution of RS, if the less stable con- 

 dition ceases to exist. 



If it was possible for two liquid phases in stable condition to 

 appear in the systems of equilibrium mentioned above, this is no 

 longer the case here. But on the other hand it is easy to get 

 these systems, if care is only taken that neither Na^ SÜ4 nor 

 Nao SO4 7 Ho 0, nor Isa^ SO4 10 ILO can come in contact with the 

 two liquid phases. Consequently Mr. dk Bkuijn has succeeded in deter- 

 mining the connoJal lines for different temperatures; care being 

 however taken to pi event the iicjuid phases to come in contact with 

 the air. It the latter happened or if only a particle of Na2S04 . 

 10 HoO was introduced, the crystallisation of ^33804 . 10 HgO fol- 

 lowed at once, and the two layers passed into one. That this must 

 necessarily be the case is shown by fig. 3, the connodal line MN, 

 determined by Mr. de Bruijn being situated not only above RS, 

 but even above LU. 



