84 MR. SCHUNCK ON RUBIAN .4ND ITS PRODUCTS OF DECOMPOSITION. 
The precipitate produced by muriatic acid in the nitrate of iron solution, was not 
entirely soluble in boiling alcohol. That part left undissolved by the latter I dis- 
solved again in nitrate of iron ; I kept the solution boiling for some time, and then 
precipitated again with muriatic acid. The precipitate, after filtering and washing, 
I treated with a boiling solution of carbonate of potash, in which it dissolved. n 
cooling, a considerable quantity of rubiacate of potash crystallized out with its ^-ua 
appearance. Some of this salt was decomposed with nitric acid, and the rubiacic 
acid so obtained was analysed. 
II. 0-5250 grm. gave 1-1595 carbonic acid and 0-1465 water. 
In 100 parts — 
Carbon 
Hydrogen 3*10 
Oxygen 36-67 
These numbers do not differ very widely from those found in the first analysis. On 
recrystallizing, however, the remainder of the salt from water, and analysing some 
acid obtained from the recrystallized salt, I obtained the following numbers ; 
III. 0*4300 grm. gave 0-9135 carbonic acid and 0-1100 water. 
In 100 parts — 
Carbon 57-93 
Hydrogen 2-84 
Oxygen 39-23 
With another portion of the recrystallized potash salt I prepared some silver salt, as 
before. 0-6260 grm. of the silver salt gave 1-0340 carbonic acid and 0-1070 watei, 
corresponding in 1 00 parts to — 
Carbon 45-04 
Hydrogen 
The mother-liquor of the salt from which No. HI. was made I precipitated with 
muriatic acid. Part of the precipitate I dissolved again in carbonate of potash, and 
the acid from the crystallized potash salt showed the following composition 
IV. 0-4010grm. gave 0-8690 carbonic acid and 0-1160 water. 
In 100 parts — 
Carbon 59-10 
Hydrogen 3-21 
Oxygen 37-69 
The remainder of the precipitate I now dissolved again in pernitrate of iron, and 
after keeping the solution boiling for several hours I precipitated again with muriatic 
acid, filtered, washed, dissolved the precipitate in carbonate of potash, filtered and 
precipitated again with muriatic acid. The precipitated rubiacic acid now gave on 
analysis the following results : — 
V. 0-3925 grm. gave 0-8240 carbonic acid and 0-1030 water. 
