Aids To Forensic Medicine And Toxicology Part 21

_Symptoms._--Giddiness, fainting, nausea, and vomiting, with syncope, muscular tremors, stupor, stertorous breathing, and insensible pupil.

Death has occurred after seventeen or eighteen pipes at a sitting.

_Post-Mortem Appearances._--Not uniform or characteristic. General relaxed condition of muscles; engorgement of cerebral and pulmonary vessels. Congestion of gastric mucous membrane.

_Treatment._--Emetics, stimulants, hypodermic injection of 1/25 grain of strychnine. Warmth to the surface by hot bottles, hot blankets.

_Method of Extraction from the Stomach._--Digest the contents of the stomach in cold distilled water and _very dilute_ sulphuric acid; strain, filter, and press residue. Evaporate the filtrate to half its bulk, digest with alcohol, and evaporate alcohol off in a water-bath.

Dissolve residue (sulphate of nicotine) in water, and make solution alkaline with potash; then shake with ether in a test-tube. Remove ether and allow it slowly to evaporate. Test resulting alkaloid.

_Tests._--No change of colour with the mineral acids. White deposit with corrosive sublimate. Sulphuric acid and bichromate of pota.s.sium give a green colour, oxide of chromium. Precipitate with bichloride of platinum and with carbazotic acid.

=Lobelia Inflata= (Indian Tobacco).--Much used in America by the Coffenite pract.i.tioners, and a valuable remedy for asthma.

_Symptoms._--Nausea, vomiting, giddiness, cold sweats, prostration.

Headache, giddiness, tremors, insensibility, and convulsions.

XLI.--HYDROCYANIC ACID

=Prussic Acid= is the most active of poisons. The diluted hydrocyanic acid of the Pharmacopoeia contains 2 per cent. of hydrocyanic acid, Scheele's 4 per cent. It is a colourless liquid, feebly acid, with odour of bitter almonds.

=Cyanide of Pota.s.sium= is largely used in photography and in electro-plating, and is also poisonous. It often contains undecomposed carbonate of pota.s.sium, which may act as a corrosive poison and cause erosion of the mucous membranes of the lips, mouth, and stomach.

=Oil of Bitter Almonds=, used as a flavouring agent, may contain (when improperly prepared) from 5 to 15 per cent. of the anhydrous acid.

_Symptoms._--The symptoms usually come on in a few seconds, and are of the shortest possible duration. There is a sudden gasp for breath, possibly a loud cry, and the patient drops down dead. If the fatal termination is prolonged for a few minutes, the symptoms are intense giddiness, pallor of the skin, dilatation of the pupils, laboured and irregular breathing, small and frequent pulse, followed by insensibility. There may be convulsions or tetanic spasms, with evacuation of urine and faeces. Death results from paralysis of the central nervous system, but artificial respiration is useless, as the drug promptly arrests the heart's action. It also kills the protoplasm of the red blood-corpuscles, rendering them useless as oxygen-carriers.

_Post-Mortem Appearances._--Skin livid, pale, or violet, with bright red patches on the dependent parts. The gastro-intestinal mucous membrane is bright red in colour, owing to the presence of cyanmethaemoglobin. Hands clenched, nails blue, jaws fixed, froth about mouth. Eyes prominent and glistening, odour of acid from body, venous system gorged.

_Treatment._--Empty the stomach by the tube at once, and wash it out with a solution of sodium thiosulphate. Strong ammonia to the nostrils.

Stimulants freely--brandy, chloric ether, ammonia, sal volatile _ad libitum_. If patient cannot swallow, inject hypodermically either brandy or ether. Hypodermic injection of 1/50 grain atropine. Douche to the face, alternately hot and cold. Death commonly occurs so rapidly that there is no time for treatment.

_Fatal Dose (Smallest)._--Half a drachm of the B.P. acid, equal to 0.6 grain of the anhydrous. _Recovery_ from 1/2 ounce of the B.P. acid.

These records are fallacious, for in specimens the percentage of anhydrous acid varies enormously. Practically, 1 grain of the anhydrous acid is fatal.

_Fatal Period._--From two to five minutes after a large dose, but may be less.

_Method of Extraction from the Stomach._--Having previously carefully fitted a watchgla.s.s to a wide-mouthed bottle, nearly fill the bottle with the contents of the stomach, blood, secretions, etc. Place a few drops of a solution of nitrate of silver on the concave surface of the watchgla.s.s, and cover the mouth of the bottle with it. The vapour of hydrocyanic acid, if present, will form a white precipitate which may be tested. Other watchgla.s.ses, treated with sulphide of ammonium or sulphate of iron and liquor pota.s.sae, will give the reactions of the acid with appropriate tests. This method removes all objections as to foreign admixture. If the acid is not at first detected, gentle warming of the bottle in a water-bath will a.s.sist the evolution of the vapour. The vapour may be obtained by distillation, but this process is open to objections to which the other is not. In some cases it becomes changed in the body into formic acid, which should therefore be sought for.

_Tests._--With nitrate of silver a white precipitate, insoluble in cold, but soluble in boiling, nitric acid. The precipitate heated, evolves cyanogen, having an odour of peach-blossoms, and burning, when lighted, with a pink flame. Liquor pota.s.sae and sulphate of iron give a brownish-green precipitate, which turns to Prussian blue with hydrochloric acid. Liquor pota.s.sae and sulphate of copper give a greenish-white precipitate, becoming white with hydrochloric acid.

Sulphide of ammonium gives sulpho-cyanide of ammonium. This develops a blood-red colour with perchloride of iron, bleached by corrosive sublimate.

XLII.--ACONITE

=Aconite= (_Aconitum Napellus_, monkshood).--Root and leaves. Poisonous property depends upon an alkaloid, aconitine. Aconite is one of the const.i.tuents of St. Jacob's Oil.

_Symptoms._--Numbness and tingling in mouth, throat, and stomach, giddiness, loss of sensation, deafness, dimness of sight, paralysis, first of the lower and then of the upper extremities, vomiting, and shallow respiration. Pupils dilated. Pulse small, irregular, finally imperceptible. The mind remains unaffected. Death often sudden.

_Post-Mortem Appearances._--Venous congestion, engorgement of brain and membranes.

_Treatment._--Emetics, stimulants freely. Best antidote is sulphate of atropine, 1/50 grain hypodermically, and also strychnine. Digitalis also useful. Warmth to whole body. Patient to make no exertion.

_Fatal Dose._--Of root or tincture, 1 drachm.

_Fatal Period._--Average, less than four hours.

_Method of Extraction from the Stomach, etc._--Extraction from contents of stomach by Stas-Otto process. It may be found in the urine; gives usual alkaloidal reactions, but no distinctive chemical test known.

_Tests._--Chiefly physiological; tingling and numbness when applied to tongue or inner surface of cheek. Effects on mice, etc. A cadaveric alkaloid or ptomaine has been found in the body, possessing many of the actions of aconitine. The presence of this substance was suggested in the Lamson trial.

The Indian aconite, _Aconitum ferox_, the Bish poison, is much more active than the European variety. It contains a large proportion of pseudaconitine, and is frequently employed in India, not only for the destruction of wild beasts, but for criminal purposes.

=Aconitine= varies much in activity according to its mode of preparation and the source from which it is derived. The most active kind is probably made from _A. ferox_.

XLIII.--DIGITALIS

All parts of the plant _Digitalis purpurea_ (purple foxglove) are poisonous. Contains the glucoside digitalin and other active principles.

_Symptoms._--Nausea, vomiting, purging, and abdominal pains. Vomited matter gra.s.s-green in colour. Headache, giddiness, and loss of sight; pupils dilated, insensitive; pulse weak, remarkably slow and irregular; cold sweat. Salivation occasionally, or syncope and stupor. Death sometimes quite suddenly.

_Post-Mortem Appearances._--Congested condition of brain and membranes; inflammation of gastric mucous membrane.

_Treatment._--Emetics freely; infusions containing tannin, as coffee, tea, oak-bark, galls, etc. Stimulants. Hypodermic injection of 1/120 grain of aconitine.

_Method of Extraction from the Stomach, etc._--Use Stas-Otto process.

_Tests for Digitalin._--A white substance, sparingly soluble in water, not changed by nitric acid; turns yellow, changing to green, with hydrochloric acid. The minutest trace of digitalin moistened with sulphuric and treated with bromine vapour gives a rose colour, turning 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.