208 



of Kipping and Pope l ), in wich a preferential deposition of the one 

 or the other component was obtained, when solutions of the sodium- 

 ammonium-tartrates, or of sodium-chlorate, nearly saturated with dex- 

 trose or with levulose, slowly crystallised. In all these cases the 

 experiments were made within a range of temperatures, where the 

 racemic compound was certainly no longer the stabler solid phase '-). 

 Ostromisslensky now suggests that this condition must always 

 be fulfilled, and even to such an extent that in the occurrence of 

 the phenomenon described, he sees a new criterion for discrimi- 

 nating between true racemic compounds and inactive, externally 

 compensated, mixtures in general. 



On the other hand, experiments recently made by Werner 3 ) on the 

 spontaneous fission of inorganic molecules, seem apparently to prove 

 the possibility of such a separation, even under circumstances where 

 racemic compounds are supposed to be really stable. This investigator 

 found, that if the active components are only less soluble than the 

 racemic substance, the optically inactive, supersaturated aqueous 

 solution may be precipitated by the addition of alcohol, or of a mixture 

 of alcohol and ether, under preferential deposition of one of the two 

 components, if only a slight excess of that active component, or of an 

 active substance isomorphous with it, be first added to the solution. 

 In such a way it appeared, for instance, possible to separate the 

 racemic oxalo-diethylenediamine-cobalti-bromide : 



Co 



Br, 



(Eine\ 



and the racemic dinitro-diethylenediamine-cobalti-Moride : 



Co 



Cl 



(Eine) z 



into their strongly active components. 4 ). It appears also possible 

 to separate the last mentioned racemoid, by precipitation with 

 alcohol, after the addition of about 10% of the corresponding 

 active o%a/o-compound. 



1) F. S. Kipping an W. J. Pope, Proc. Chem. Soc. 14. 113. (1898); Journ. 

 Chem. Soc. London 73. 606. (1898); Zeits. f. Kryst. 30. 472. (1899); Chem. News 

 75. 46. (1897); Cf. also: Ch. Soret, Archiv. des Sc. phys. et nat. de Geneve 

 (4). 7. 80. (1899). 



2 ) Of course the case of sodium-chlorate is not considered now. 



3) A. Werner, Ber. d. d. Chem. Ges. 47. 1955, 2171, 2179. (1914). 



4 ) Here and in the following, Eine is again used as an abreviation for ethylene- 

 diamine: 



