urning
to mauve. This is very delicate, but in experienced hands the
physiological test is more reliable. The chemist who has had no
practical experience in pharmacological methods would be wiser to keep
to his chemical tests.

XLIV.--NUX VOMICA, STRYCHNINE, AND BRUCINE

=Nux Vomica= consists of the seeds of the _Strychnos nux vomica_. From
these strychnine and brucine are obtained. The symptoms, post-mortem
appearances, and treatment, of poisoning by nux vomica are the same as
for strychnine.

=Strychnine= is a powerful poison, and forms the active ingredient of
many 'vermin-killers.' It occurs as a white powder or as colourless
crystals, with a persistent bitter taste; very slightly soluble in
water; more or less soluble in benzol, ether, and alcohol.

_Symptoms._--Sense of suffocation, twitchings of muscles, followed by
tetanic convulsions and opisthotonos, each lasting half to two minutes.
Mental faculties unaffected, face congested and anxious; eyes staring,
lips livid; much thirst. The period of accession of the symptoms varies
with the mode of administration of the poison. Symptoms, as a rule, come
on soon after food has been taken. Patient may die within a few hours
from asphyxia or from exhaustion.

In _Tetanus_ there is usually history of a wound; the symptoms come on
slowly; lockjaw is an early symptom, and only later complete
convulsions; the intervals between the fits are never entirely free from
rigidity. Death is delayed for some days.

_Post-Mortem Appearances._--Heart empty, blood fluid, rigor mortis
persistent. Hands usually clenched; feet arched and inverted. Congestion
of brain, spinal cord, and lungs.

_Treatment._--Emetics or stomach-pump if the patient is deeply
anaesthetized. Tannic acid and permanganate of potassium. Bromide of
potassium 1/2 ounce with chloral 30 grains, repeated if necessary.

_Fatal Dose (Smallest)._--Quarter of a grain.

_Fatal Period (Shortest)._--Ten minutes; usually two to four hours.

_Method of Extraction from the Stomach._--The alkaloid may be separated
by the process of Stas-Otto.

_Tests._--Strychnine has a characteristic, very bitter taste; it imparts
this taste to even very dilute solutions; it is unaffected by sulphuric
acid, but gives a purple-blue colour, changing to crimson and light red,
when the edge of this solution is touched with dioxide of manganese,
potassium bichromate, ferricyanide of potassium, or permanganate of
potassium. This t