Proceedings of the Royal Society. 
93 
perfectly clear, and, even where violently agitated, no precipitate 
makes its appearance. At the end of twenty-four hours, the fluid 
is still clear, although I have once or twice, when the solution was 
concentrated, observed a few needle-shaped crystals of the base at 
the bottom of the fluid. 
Acetate of cinchonine, in moderately diluted solution, begins to 
deposit small crystals of the base almost immediately after the sub- 
acetate is added, and the quantity goes on increasing for some hours. 
Agitation produces an immediate precipitate. 
Quinine is not deposited from its acetate, even on standing during 
the night, provided the solution be dilute ; but if concentrated and 
briskly shaken, small tufts are occasionally thrown down after stand- 
ing for some hours. 
Morphine and thebaine are not thrown down from solutions of 
their acetates, even after standing ; and codeine, as might be anti- 
cipated from its solubility in water, is entirely unaffected. On the 
other hand, narcotine, papaverine, and narcine are instantaneously 
precipitated as bulky powders. 
These facts indicate the importance of a more minute attention 
being paid to the deportment of the vegetable alkaloids with sub- 
acetate of lead. We observe that in the case of the two cinchona 
and the two nux vomica alkaloids, the difference is very marked, 
and the reaction might be used as a means of separation, and pos- 
sibly also of purification. Most of the substances found in vegetable 
extracts, such as gum, & c., are precipitated by subacetate of lead ; 
and in the case of the stronger bases, it might be possible to effect 
purification by extracting with acetic acid, and precipitating with the 
subacetate. The strong base would then remain in solution along 
with excess of lead, which being precipitated with sulphuretted hy- 
drogen, would carry down colouring matters, and leave a pure ace- 
tate in solution. I have not attempted to put this process into prac- 
tice, but recommend a trial of it to these chemists who are engaged 
with the examination of the natural alkaloids. 
2. On the Colouring Matter of Persian Berries. By Mr John 
Gellatly, assistant to Dr Anderson, Glasgow. 
Two varieties of the seeds of the Rhamnus tinctoria are found in 
commerce, known by the names of Persian and Turkish berries. The 
