'02 



than onr former measurements with ilie hievogyratoi-j componeiil 

 indicate, — a deviation probably caused by the uncertainty of the 

 readings in the interval of the absorption-band. But the correspondence 

 of the curves cannot be doubted any longer. Continued study of 

 the single crystals dejiosited from the solution, taught, that besides 

 the lefthanded crystals, also those of the laevogyratory component 

 occur. It is commonly quite impossible to recognise the two kinds of 

 crystals from eacli other by their outward appearance, and thus to 

 select them, because the facets of the right- or lefthanded trape- 

 zohedra or trigonal bipyramids are commonly lacking, so that the 

 aspect of the crystals is in both cases quite the same. 



It cannot be doubled therefore any longer, that we have found 

 here a first instance of a tissiou into optically active antipodes of 

 such complex metallic compounds, bi/ s[KnHaneous crystallisation; 

 for the case of potassiwn-rhodimn-o.valate formerly indicated by 

 Wkknkh as an instance of this kind, can no longer be considered 

 as such, as was some time ago proved by us. ^) 



For the purpose of justifying this view, it was necessary to deter- 

 mine the temperatnrf of transition of the racemic compound into its 

 antipodes as accurately as possible. This was done in two ways: 

 by means of the dilatometrical tnelhod, and by the study of the 



cn.WOgr.yfater: 



40 

 39 

 38 

 37 

 36 

 35 



34 



it3°2 



0' 3° 6° 9' W 15° 18" 21 



Fig. 4. 



^J^mJ)cralure^ 



1) F. M. Jaf.ger. Proceed. Kon. Akad. v. Wet. Amsterdam. 20. 264, 265.(1917). 



