MR. SCHUNCK ON RUBIAN AND ITS PRODUCTS OF DECOMPOSITION. 79 
tuents. It dissolves in ammonia and carbonate of soda with a dark-brown colour, 
and is reprecipitated unchanged by acids. Even if it be dissolved in caustic soda, and an 
excess of sulphuretted hydrogen be passed through the solution, the precipitate after- 
wards produced by acids yields nothing to boiling alcohol, which proves that the 
verantine has not thereby been set at liberty. By treating it with boiling alcohol 
until all the matter soluble in alcohol is removed, then dissolving it in carbonate of 
soda, fikering from a small quantity of oxide of tin, then reprecipitating with acid, it 
is obtained in dark brown flocks, which when dry cohere into black, brittle, shining 
masses. Its analysis now gave the following results : — 
I. 0'5930grm., dried at 100° C., gave 0‘6500 carbonic acid and O'lSOO water. 
0'3410grm., heated in a crucible until all the organic matter was destroyed, gave 
0‘1580grm. peroxide of tin, equivalent to 0'1411 protoxide of tin. 
II. 0-8390 grm. gave 0-9240 carbonic acid and 0-2455 water. 
It contains, therefore, in 100 parts — 
I. II. 
Carbon 29*89 30-03 
Hydrogen 3*37 3*25 
Oxygen 25 '36 
Protoxide of tin . . . 41 '38 
The formula C 56 Hgg 036 + 7 Sn 0 = 4 C ,4 Hj Oj-f 7 Sn 0+ 16HO requires in 100 parts — 
Carbon 29'76 
Hydrogen 3' 18 
Oxygen 25'52 
Protoxide of tin 41'54 
The sugar obtained by the fermentation of rubian does not differ in its properties, 
as I mentioned before, from that derived from the action of acids on rubian. In 
composition too it does not materially differ from the latter. I succeeded, however, 
by exposing it for a considerable length of time to a temperature of 100 ° C., in 
depriving it of two atoms more of water, as will be seen by the following analysis: — 
0*5540 grm. gave 0*8745 carbonic acid and 0*3055 water. 
These numbers correspond with the formula C , 2 H,, Ojo, as will be seen by the 
following calculation : — 
Carbon. . . . 
Eqs. 
. 12 
72 
Calculated. 
44*44 
Found. 
43*84 
Hydrogen . . . 
. 10 
10 
6*17 
6*23 
Oxygen . . 
. 10 
80 
49*39 
49*93 
162 
100-00 
100*00 
On subjecting it, however, for some time longer to the same temperature, it became 
very brown, and its analysis now showed that it had absorbed oxygen. 
0*5820 grm. now gave 0*8745 carbonic acid and 0*3000 water. 
M 2 
