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 anæsthetized. 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 test is so delicate as to show the 1/25000 of a grain of the alkaloid. A very minute quantity (1/5000 grain) in solution placed on the skin of a frog after drying causes tetanic convulsions.
Brucine.—This alkaloid, found associated with strychnine, possesses the same properties, though in a less powerful degree. Nitric acid gives a blood-red colour, changed to purple with protochloride of tin.