these facts will help to explain the following details, which may be
modified to suit individual cases: (1) Treat the organic matter, after
distillation for the volatile substances just mentioned, with twice its
weight of absolute alcohol, free from fusel oil, to which from 10 to 30
grains of tartaric or oxalic acid have been added, and subject to a
gentle heat. (2) Cool the mixture and filter; wash the residue with
strong alcohol, and mix the filtrates. _The residue may be set aside for
the detection of the metallic poisons, if suspected._ Expel the alcohol
by careful evaporation. On the evaporation of the alcohol the resinous
and fatty matters separate. Filter through a filter moistened with
water. Evaporate the filtrate to a syrup, and extract with successive
portions of absolute alcohol. Filter through a filter moistened with
alcohol. Evaporate filtrate to dryness, and dissolve residue in water,
the solution being made distinctly acid. Now shake watery solution with
ether. (3) Ether from the acid solution dissolves out _colchicin_,
_digitalin_, _cantharidin_, and _picrotoxin_, and traces of _veratrine_
and _atropine_. Separate the ethereal solution and evaporate. Hot water
will now dissolve out _picrotoxin_, _colchicin_, and _digitalin_, but
not cantharidin. (4) The remaining acid watery liquid, holding the other
alkaloids in solution or suspension, is made strongly alkaline with
soda, mixed with four or five times its bulk of ether, chloroform, or
benzole, briskly shaken, and left to rest. The ether floats on the
surface, holding the alkaloids, except morphine, in solution. (5) A part
of this ethereal solution is poured into a watch-glass and allowed to
evaporate. If the alkaloid is volatile, oily streaks appear on the
glass; if not volatile, crystalline traces will be visible. If a
volatile alkaloid, add a few pieces of calcium chloride to ethereal
solution to absorb the water; draw off the ethereal solution with a
pipette, allow it to evaporate, and test the residue for the alkaloids,
conine and nicotine.

If a fixed alkaloid, treat the acid solution with soda or potash and
ether, evaporate ethereal solution after separation, when the solid
alkaloid will be left in an impure state. To purify it, add a small
quantity of dilute sulphuric acid, and, after evaporating to
three-quarters of its bulk, add a saturated solution of carbonate of
potash or soda. Absolute alcohol will then dissolve out the alkaloid,
and leave