82 
MR. SCHUNCK ON RUBIAN AND ITS PRODUCTS OF DECOMPOSITION. 
I was at first unable to explain the great discrepancy here seen, as the new prepa- 
ration both of the acid and the potash salt had the same appearance as usual. Before 
proceeding to explain how this discrepancy arose, 1 may state that the analysis just 
given corresponds with the formula which requires in 100 parts— 
Carbon 6r93 
Hydrogen 3‘22 
Oxygen 34‘85 
With the same specimen of potash salt as that employed for the preparation of the 
acid, I made a quantity of silver salt by dissolving the potash salt in water, and 
adding nitrate of silver. A brilliant cinnabar~red precipitate fell, which was filtered, 
washed and dried. It was not decomposed either by light or by the heat of boiling 
water. 
0’5800 grm. of this salt, dried in the water-bath, gave 0’9800 carbonic acid and 
O' 11 50 water. 
0‘3310 grm., treated in a crucible with muriatic acid, and heated until all the 
organic matter was destroyed, gave 0'1120 chloride of silver. 
These numbers lead to the following composition : — 
Carbon . . . 
Eqs. 
. 64 
384 
Calculated. 
46-04 
Found. 
46-08 
Hydrogen . . 
. 18 
18 
2-15 
2*20 
Oxygen . . . 
. 25 
200 
24-00 
24-37 
Oxide of silver 
2 
232 
27'81 
27-35 
834 
100-00 
100-00 
I now took a fresh quantity of waste dye liquor, and divided it into two parts. To 
the first part I added acid. The precipitate 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 properties of rubiafine. Their com- 
position, 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 I also added acid, and the precipitate, after strain- 
ing the liquor through calico, and washing with water, I treated with a boiling 
