210 



central metal-atom on the specific light-absorption (colour) of these 

 salts and on the whole character of the rotation-dispersion. 



The yellow crystals obtained on evaporating the original mother- 

 liquid of the stri/chrwie-'sahs to Vs or '/, of its volume, gave after 

 treatment with potassium-iodide a fraction which appeared to be 

 the 2)z<?'^ laevogyrate salt. The following measurements, made with 

 a solution containing one grammolecule of the hydrated salt in 

 42, y? Liters of the liquid, may make this clear: 



A comparison of the rotations for the same wave-lengths in the 

 case of the corresponding rhoclium-sa,\t with the here described 



