78 MR. SCHUNCK ON RUBIAN AND ITS PRODUCTS OF DECOxMPOSlTION. 
I. 0-5210 grin, alizarine, produced by the action of the ferment on rubian, lost, on 
being heated in the water-bath, 0-0920 waters 17’65 per cent. 
0-2500 grm. of the dry substance gave 0-6380 carbonic acid and 0-0960 water. 
II. 0-4220 grm., obtained by allowing an extract of madder with tepid water to 
ferment, lost, on being heated, 0-0750 waters 1777 per cent. 
0-3225 grm. of the dry substance gave 0-8230 carbonic acid and 0-1170 water. 
These numbers correspond in 
100 parts to — 
I. 
II. 
Carbon . . 
.... 69-59 
69-59 
Hydrogen . 
.... 4-26 
4-03 
Oxygen . . 
.... 26-15 
26-38 
The quantity of rubiretine and verantine formed by the fermentation of rubian does 
not seem to be so large as it is, when acids or alkalies are employed for its decompo- 
sition, and as the process of separating and purifying the products of fermentation is, 
on account of the number of products formed, rather more complicated, the quantity 
of each substance obtained in a pure state is but small. The following analyses of 
these two substances were made with specimens obtained by the fermentation of an 
extract of madder; and even by preparing them in this manner I had some difficulty 
ill procuring a sufficient quantity for examination, because the rubiretine formed by 
fermentation is always found mixed with rubiadipine, from which it is with difficulty 
freed ; and the verantine is for the most part obtained in combination with oxide of 
tin, from which I have found it impossible to separate it. 
0-3445 grm. rubiretine gave 0-8580 carbonic acid and 0-1695 water. 
This gives in 100 parts — 
Carbon • 6/ -92 
Hydrogen 
Oxygen ........ 26-62 
0-3705 grm. verantine gave 0-9010 carbonic acid and 0-1420 water. 
In 100 parts — 
Carbon 66-32 
Hydrogen 4-25 
Oxygen 29-43 
The great excess of carbon in this analysis indicates an admixture of alizarine. 
This proceeds from the circumstance that the method of separating verantine and 
alizarine, by means of acetate of copper, is not absolute. When these two substances 
are present together in solution, acetate of copper precipitates a portion of the aliza- 
rine together with the verantine, and the latter can afterwards only be purified by 
repeated solution in boiling alcohol, and deposition from the boiling solution. 
The compound of verantine and oxide of tin, obtained in the process employed for 
purifying the rubiafine, cannot, as I mentioned before, be separated into its consti- 
