276 Dr. Schunck on Ruhian and its Products of Decomposition^. 



I have adopted the name of chlororubiadine, under the assump- 

 tion that the true formula for rubiadine is C^H^^O^. Never- 

 theless I have not succeeded in converting the latter into chloro- 

 rubiadine by means of chlorine, nor in substituting the chlorine 

 in chlororubiadine by hydrogen and thus forming rubiadine. 

 If chlororubiadine be suspended in water to which an amalgam 

 of potassium (1 part of potassium to 100 mercilry) is added, it 

 dissolves with a dirty red colour without much hydrogen being 

 evolved. The liquid gives a greenish-yellow flocculent precipi- 

 tate on the addition of nitric acid. This precipitate contains no 

 chlorine, but it docs not contain any rubiadine, since it gives, 

 after being dried and heated between two watch-glasses, none 

 of the crystalline sublimate characteristic of rubiadine. The 

 liquid filtered from this precipitate gives an abundant precipi- 

 tate with nitrate of silver. 



Hydrosulphate of ammonia dissolves chlororubiadine, forming 

 a red solution, which on standing becomes of a fine purple, and 

 after some hours brownish-red. If nitric acid be added to the 

 solution as soon as it has acquired a purple colour, an orange- 

 coloured flocculent precipitate falls. This precipitate is free 

 both from sulphur and chlorine, the chlorine of the chlororu- 

 biadine being found in the filtered liquid, but it contains no 

 rubiadine. It is only partly soluble in boiling alcohol, but dis- 

 solves easily in boiling nitric ,acid, the solution depositing on 

 standing some long dark yellow sword-shaped crystals. 



If crystallized rubiadine, obtained by the decomposition of 

 rubihydran with acid, be dissolved in caustic alkali and repreci- 

 pitated with acid, and if the precipitated flocks after filtering and 

 washing be suspended in water, and a current of chlorine gas 

 be passed through the liquid, the flocks become somewhat paler 

 in colour. If they be now collected on a filter and washed with 

 water and then treated with cold alcohol, the greater part dis- 

 solves, leaving undissolved a small quantity of a white powder, 

 which has all the properties of a body which I shall describe 

 presently, and which is formed by the action of chlorine on 

 chlororubian. If the alcoholic solution be evaporated to dryness 

 and a little cold alcohol be again added to the residue, the alco- 

 hol again dissolves a great part, leaving undissolved a yellowish- 

 green granular powder, which resembles but is not identical 

 with chlororubiadine. The alcoholic solution leaves on evapo- 

 ration a brown, transparent, resinous substance. This substance 

 contains a large quantity of chlorine. It dissolves in caustic 

 soda with a brown colour, and is reprecipitated by acids in 

 yellow flocks, which melt in the boiling liquid to brown oily 

 drops. I found it to contain the following quantities of carbon 

 and hydrogen : — 



