QUININE AND CINCHONINE. 
239 
In. consequence of this treatment only one-third of the cin- 
chonine separated subsequently in coloured crystals. On 
the subsequent addition of alkalies, a dark brown extremely- 
bitter substance resembling turpentine subsided, the solu- 
tion of Avhich in sulphuric acid was sent to the author for 
examination. The solution was diluted with water, filtered 
and mixed with an excess of carbonate of soda. The sepa- 
rated mass was again 'dissolved in dilute sulphuric acid, 
treated as before wUh carbonate of soda, and now some 
sulphate of soda added to it, while the liquid was heated 
in the water-bath. On cooling, a considerable quantity of 
a nearly black mass had separated, while the supernatant 
liquid was pale brown. On the addition of ammonia^ this 
liquid now deposited an almost perfectly white pulverulent 
precipitate, which gradually aggregated to a dark yellowish- 
brown turpentine-like mass, which after sufficient washing 
with water was dried in the water-bath. In this state it 
exactly resembled the syrupy coloured residue, insoluble in 
pure ether, which remains when the extract of quinoidine 
with ordinary ether is treated after evaporation of the latter 
wuh ether containing no water or spirit. Both were dis- 
solved in absolute alcohol, and digested with animal char- 
coal at 104°, upon which both solutions were evaporated 
in the water-bath until their weight no longer varied. In 
this state both substances formed dark brown tenacious 
masses, which in thin layers were transparent, and which 
possessed an odour similar to commercial quinoidine. They 
dissolved in every proportion in strong alcohol, but not in 
ether and [water. Equal quantities of the two substances 
saturated the same amounts of dilute acids, and were so 
completely precipitated from the solutions by carbonate of 
soda, that the liquid, after removal of the precipitate, was 
nearly void of taste and colour. Both substances behave 
precisely similar on being heated ; they first melted, then 
disengaged some vapours of a bitter taste, and left a cinder 
which burnt without any residue, but with considerable 
