VEGETABLES AS THE SOURCES OF ARTIFICIAL ALKALOIDS. 
49 
solved. The several liquors were then mixed together, and were boiled for a couple 
of hours in a copper pan, or still more conveniently in an iron pot lined with enamel. 
This dissipated the acetone, wood-spirit, and a great deal of the neutral and acid 
empyreumatic volatile oils contained in the liquid. The boiling also rendered the 
tar less soluble by converting it and the fixed oils into imperfect resins. The acid 
liquor was then left at rest till it was quite cold, when it was passed through a cloth 
filter containing a quantity of pounded charcoal, which retained the greater portion 
of the resinous matter. The clear liquid was then introduced into a capacious still, 
and largely supersaturated either with quick-lime in fine powder, or with carbonate 
of soda, as was found most convenient. 
As soon as heat was applied to the still a great deal of ammonia was evolved, and 
when the liquid boiled a quantity of oily bases began to appear in the ammoniacal 
liquor which passed into the receiver. Their amount increased as the distillation 
proceeded. As the first half of the liquid which came over was by much the richest 
in bases, it was collected separately from the succeeding portions, which contained 
scarcely any undissolved oil, but consisted chiefly of an aqueous solution of the bases. 
The distillation was continued however till the liquid which condensed in the 
receiver had only a slightly alkaline reaction. The mixture of oils which collected 
on the surface of the first portion of the distillation was drawn off* with a pipette and 
then saturated with muriatic acid, which left any neutral oil which had been mixed 
with it undissolved. The oil was removed by passing the solution through a wet 
paper filter. The clear liquid was next supersaturated with carbonate of soda, and 
rectified in a large glass retort. It was found advantageous to employ a great excess 
of alkali for this purpose, as these bases are much more soluble in water than in 
strong alkaline lyes, and therefore distil over more readily from solutions which are 
strongly alkaline. The bases which passed over into the receiver were drawn off, as 
before, by means of a pipette from the ammoniacal liquor on which they floated, and 
were collected in any suitable bottle. The weak alkaline liquors of the previous di- 
stillation, which had ceased to yield bases by simple rectification, were again neutral- 
ized with muriatic acid, and cautiously concentrated to about half, or even a third, 
of their bulk, according to their state of dilution. Care should be taken however not 
to concentrate these liquors, unless in case of necessity, as long-continued boiling has 
always the effect of destroying a large portion of the bases, which are oxidated and 
converted into dark-coloured resins. The bases were again rectified with water, 
which removed much of the resinous matter which had come over with them during 
the previous distillations. As they still however retained a good deal of ammonia, 
from which it was necessary to free them, they were washed by being repeatedly 
agitated with successive portions of a strong solution of potash, which dissolved the 
ammonia and retained it in solution. The mixture of the lye and the bases was then 
poured into a long narrow-necked funnel, which was closed at the bottom, and the 
whole was left for a short time to subside. The bases quickly separated from the 
MDCCCL. 
H 
