MR. SCHUNCK ON RUBIAN AND ITS PRODUCTS OF DECOMPOSITION. 
83 
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 rubiafine 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 rubiacate of potash by means of sulphuretted hydrogen, I 
found to contain in 100 parts — 
Carbon 67*01 
Hydrogen 3'28 
Oxygen 29*71 
The most probable formula for this substance is C 32 Hu Oi#, which requires in 100 
parts 
Carbon 67*84 
Hydrogen 3*88 
Oxygen 28*28 
The remainder of the substance I dissolved in boiling alcohol, and added acetate 
of lead. This gave a dark red precipitate, which after filtering, washing with alcohol, 
and drying, was found to have the following composition : — 
0*5470 grm., dried at 100° C., gave 0*6630 carbonic acid and 0*0890 water. 
0*4060 grm. gave 0*2800 sulphate of lead, containing 0*20602 oxide of lead. 
These numbers correspond with the formula 3 C 32 H,i Oio+ 8 PbO, as the following 
calculation shows : — 
Carbon . . . 
Eqs. 
. 96 
576 
Calculated. 
33*05 
Found. 
33*05 
Hydrogen . . 
. 33 
33 
1*89 
1*80 
Oxygen . . . 
. 30 
240 
13*78 
14*41 
Oxide of lead . 
8 
893*6 
51*28 
50*74 
1742*6 
100*00 
100*00 
