205 



ittli- probability of it. According to Kruyt and Van (In Limit n '), 

 . in to occur only to an unapprcciable amount in the cases 



u]> till now, if present in the liquid state at all. 

 Shi bat a '-') proved moreover that the absorption of light of the 

 racemic complex co&aW-salts in aqueous solutions, and that of tin -ir 

 >i>tiral antipodes under the same conditions, is completely the same. 

 fact seems also to indicate that no such racemic compounds 

 ly exist in solutions to any appreciable degree. 

 YVr have seen that as long as the racemoid is stable, the concen- 

 tration of the metastable solution x which possibly is in temporary 

 equilibrium with a mixture of both components, will be greater than 

 that of the stable solution in equilibrium with the racemic compound 

 at the same temperature. As a complement of this it may be remarked 

 that the reverse must be the case if the racemoid is no longer the 

 stabler solid phase, as is easily seen from the figures 737 and 158, when 

 tin- inactive solution m is compared with/, which is a metastable op- 

 tically inactive solution, eventually in equilibrium with the racemic 

 substance at the same temperature. Here also therefore the less stable 

 phase has always the greater solubility, as is observed in all such cases. 

 Of course it would have also been possible to deduce all these 

 relations from sections through the tridimensional model parallel 

 to the coordinate-planes XOT or YOT respectively, i. e. by means 

 of temperature-concentration-diagrams. This is the method princi- 

 pally followed by Van 't Hoff, in his work on the formation and 

 decomposition of double-salts 3 ). 



4. The solution of the problem why a number of racemoids 

 can be spontaneously resolved by crystallisation and separating 

 both kinds of enantiomorphous crystals from each other by selection, 

 while others cannot be separated in this way, - - must evidently 

 depend on the situation of the transition-temperature. If this lies 

 the neighbourhood of the temperature of crystallisation and 

 ithin the range of temperatures where the substances can exist 

 without decomposition, there will be great probability that the 

 spontaneous fission mentioned above, really occurs, be it at higher 



1) T. Van der Linden, Ber. d. d. Chem. Ges. 44. 963. (1911); H. R. Kruyt, 

 ibid. 44. 995. (1911); A. Ladenburg, ibid. 44. 1677. (1911). 



2) Y. Shibata, Journal of the College of Science Imp. Univ. Tokyo, S7. Art. 2. 

 p. 28. (1915). 



8 ) J. H. Van 't Hoff, Vorlesungen u. Bildung und Spaltung von Doppel- 

 salzen, loco cit. 



