196 DR T. ANDERSON ON SOME OF THE 
Papaverine. 
In the purification of narcotine by repeated crystallizations from boiling alco- 
hol, in the manner described in the paper already referred to, the mother liquors 
of each successive crystallization had been carefully preserved, and at the conclu- 
sion of the investigation they were worked up for the purpose of obtaining the 
very considerable quantity of narcotine which they obviously still contained. For 
this purpose the fluids were mixed together, and the greater part of the alcohol 
separated by distillation. The residue on being left to itself, deposited a con- 
siderable quantity of dark-coloured crystals mixed with resinous matters, which 
were collected on a cloth and expressed, and the fluid which passed through was 
again concentrated and allowed to crystallize, and this was repeated until it 
ceased to yield anything on further evaporation. The crystals so obtained were 
dissolved in the smallest possible quantity of boiling alcohol, from which they 
were deposited in a tolerably colourless state as the liquid cooled. On further 
concentrating this mother liquor, and again allowing it to cool, it became 
filled with crystals of a substance obviously much more soluble in alcohol 
than narcctine, and differing from it in its general characters. It was parti- 
cularly observed to restore the blue of reddened litmus, to dissolve readily in 
acids, and to saturate them completely; properties not possessed by narcotine. 
Its ready solubility in alcohol led at first to the suspicion that it might be the- 
baine, which had been already observed accompanying the narcotine, but the 
difference in its crystalline form, as well as its complete precipitation from its 
solution in acetic acid, by subacetate of lead, proved it to be different. A very 
few experiments sufficed to show that the base thus obtained was still conta- 
minated with narcotine, from which it might no doubt have been separated by 
repeated crystallizations; but as this would have been an extremely tedious pro- 
cess, and have caused the loss of a considerable quantity of material, I preferred 
a method founded on the marked difference between its basic properties and those 
of narcotine. The whole of the crystals obtained from the mother liquors, and con- 
sisting partly of narcotine and partly of this other base, were reduced to a fine 
powder, and digested with a limited quantity of acetic acid. The acid was ra- 
pidly saturated, and as soon as the fluid had lost its acid reaction it was filtered 
from the undissolved portion, which was again treated with the acid; and this 
treatment was cautiously repeated as long as it continued to be thoroughly satu- 
rated. The solution was then filtered from the undissolved narcotine, precipitated 
by ammonia, and the precipitate crystallized from boiling alcohol. The base was 
now pure, and analysis showed it to be papaverine, with which its characters were 
found to agree in all respects. A consideration of the properties of papaverine 
now enabled me to perceive that it must have been present in very large quan- 
tity in the mother liquor obtained in the first crystallization of the crude narco- 
