214 



in the same way as in the experiments of Kipping and Pope l ), 

 in which a preferential deposition of the one or the other component 

 was obtained, when solutions of the sodium-ammonium-tar tr at es or 

 of sodium-chlorate, nearly saturated with dextrose 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 2 ). Ostromisslensky 

 now suggests that this condition must always be fulfilled, and even 

 to such an extent that in the occurrence of the phenomenon des- 

 cribed, he sees a new criterion for discriminating between true racemic 

 compounds and inactive, externally compensated mixtures in general. 

 On the other hand, experiments made by Werner 3 ) some years ago 

 on the spontaneous fission of inorganic molecules, apparently seemed 

 to prove the possibility of such a separation, even under circumstan- 

 ces 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 depositipn of one 

 of the two components, if only a slight excess of that active compo- 

 nent, 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, 



and the racemic dinitro-diethylenediamine-cobalti-chloride : 



Co ^r% 2 \ci 



(Eine) 2 \ 



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



J ) F. S. Kipping and 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 ethvlene- 

 diamine; 



