428 Dr. Schunck on Rubian and its Products of Decomposition. 



I now took a fresh quantity of waste dye liquor, and divided 

 it into two parts. To the first part I added acid. The precipi- 

 tate produced by the acid was treated with boiling alcohol, which 

 dissolved a small part with a deep yellow colour, and after being 

 filtered boiling hot and allowed to cool, deposited a quantity of 

 orange-coloured powder. This powder I dissolved again in 

 boiling alcohol, and to the boiling solution I added hydrated 

 protoxide of tin, and filtered boiling hot. The liquid, which 

 had become light yellow, deposited on cooling a quantity of light 

 yellow needles. These needles had the appearance and proper- 

 ties of rubiafine. Their composition, however, proved them to 

 be a distinct substance. 



0*1515 grm. gave 0-3730 carbonic acid and 0*0540 water. 

 In 100 parts, therefore, it consisted of — 



Carbon 67*14 



Hydrogen 3*96 



Oxygen 28*90 



To the other part of the liquor 1 also added acid, and the 

 precipitate, after straining the liquor through calico, and washing 

 with water, 1 treated with a boiling solution of pernitrate of iron, 

 which dissolved a portion with a dark purplish-brown colour. 

 Muriatic acid produced in the filtered liquid a yellow precipitate, 

 which after filtering and washing with water, I treated with 

 boiling alcohol. The alcohol being filtered boiling hot, deposited 

 on cooling a yellow powder, which on being redissolved in fresh 

 boiling alcohol, yielded a quantity of yellow shining plates and 

 needles. These corresponded in all their properties with rubia- 

 fine and rubiacine. By treatment with pernitrate of iron they 

 were convertible into rubiacic acid. 



0*2355 grm. gave 0*5790 carbonic acid and 0*0860 water. 

 In 100 parts it contained, therefore, — 



Carbon 67*05 



Hydrogen 4*05 



Oxygen 28*90 



This analysis proves that the substance contained in the 

 liquor existed in the same state before and after the treatment 

 with pernitrate of iron, and that the latter, in the first instance 

 at least, merely dissolved without changing it. A comparison 

 of the composition of this substance with that of the body which 

 I formerly called rubiacine, proves that they are identical. A 

 specimen of rubiacine obtained on a former occasion from rubia- 

 cate of potash by means of sulphuretted hydrogen, I found to 

 contain in 100 parts — 



Carbon 67*01 



Hydrogen 3*28 



Oxygen 29-71 



