Chapter 30 of 31 · 2416 words · ~12 min read

CHAPTER XIV

EXCITOMOTORY POISONS

NUX VOMICA STRYCHNINE

Some of the most poisonous known plants belong to the genus _Strychnos_ (_N.O. Loganiaceæ_).

The Java poison, Upas Tieuté, is a watery extract of _S. Tieuté_; the basis of the poison used in Guiana, and known as Wourali, Ourari, Urari, or Curare, is the juice of _S. toxifera_. _S. nux vomica_, the Koochla tree, produces the nux vomica seeds of commerce; and the bark of the tree has been accidentally substituted for cusparia, or angustura bark, hence it is known as _false angustura_ bark. The substitution is attended with considerable risk, on account of the strychnine which the false bark contains. It may be known by its being quilled, externally covered with white lichenous spots, and the internal surface becoming _blood-red_ when touched with nitric acid. This reaction, which depends upon the presence of an alkaloid, brucine, _does not_ occur when true angustura bark is thus treated.

NUX VOMICA

_The Seeds of S. Nux Vomica_

The British Pharmacopœia contains an extract and a tincture. The alkaloid strychnine is the active principle of the seeds and other parts of the plant. Another alkaloid, brucine, is also found, and is poisonous.

The symptoms and _post-mortem_ appearances and treatment will be detailed under the head of strychnine. The brown powder of the seeds may, in some cases, be seen adhering to the mucous membrane of the stomach.

STRYCHNINE

Strychnine is very slightly soluble in cold water to the extent of one

## part in 8300; in boiling water one part dissolves in about 2500. It is

more soluble in alcohol, and very soluble in chloroform or ether and chloroform mixed.

It has a bitter taste, so intense, that one part in 70,000 of water can be detected by the taste. Strychnine is not easily decomposed--it resists the action of warm strong sulphuric acid, and is not altered by putrefactive processes when present in viscera. It has been discovered in the body 322 days after death in one case, 368 days in another.

[Illustration: Fig. 40.--Photo-micrograph of crystals of strychnine sulphate from aqueous solution, × 50. (R. J. M. Buchanan.)]

[Illustration: Fig. 41.--Photo-micrograph of crystal of strychnine sulphate from aqueous solution, × 50. (R. J. M. Buchanan.)]

Allen detected strychnine in the residue of some viscera from a person who had died of strychnine poisoning, and which he had kept in a jar for six years. Richter found the alkaloid at the end of eleven years in putrid tissues which had been exposed to the air all that time in open vessels.

_Symptoms._--Should the poison be in solution, the patient complains of a hot and intensely bitter taste during swallowing. The effects of the poison depending to a great extent on the mode of administration, become manifest in from a few minutes to an hour or more after it is taken. The earliest symptoms are a feeling of suffocation and great difficulty of breathing. These come on suddenly, without any premonitory warnings. Twitching of the muscles rapidly pass into tetanic convulsions of nearly all the muscles of the body, which are simultaneously affected. The head after several jerks becomes stiffened; the neck rigid; the body curved forward, quite stiff, and resting on the back of the head and heels. The face is congested, and the countenance expresses intense anxiety; the eyes staring, the mouth open, and the lips livid. The throat is dry, the thirst great; but when an attempt is made to drink, the jaws are spasmodically closed, and a piece of the vessel may be bitten out. During the intervals of the paroxysms the intellect is usually clear, and the patient appears conscious of his danger, frequently exclaiming, “I shall die!” He is also conscious of the accession of the paroxysms, telling those around him of their approach, and asking to be held. In the case of J. P. Cook, poisoned by Palmer, those about him tried to raise him, but he was so stiff that they found it impossible. He then said, “Turn me over,” which they did, and he died in a few minutes. Intense pain is felt, due to the powerful contractions of the muscles. After the lapse of a minute or two, the spasms subside, a sudden lull takes place, during which the patient feels exhausted and his skin is bathed in sweat.

In poisoning by strychnine, the jaws are slightly, if at all, affected, trismus is a late symptom, and occurs only during a convulsive seizure.

In tetanus the result of disease, the locking of the jaws is an early and a marked symptom.

As death approaches the fits become more frequent, and the patient dies from exhaustion or suffocation.

_Post-mortem Appearances._--There is no characteristic appearance found after death. The blood is fluid, the heart empty, with some congestion of the membranes of the brain. Absence of all cause for so violent and sudden a death. _Rigor mortis_ is prolonged for some time.

_Fatal Period._--The rapidity in the accession of the symptoms and fatal termination will, to some extent, depend upon the form in which the poison is taken--_i.e._ in solution or in pill. In most cases the symptoms appear in from three or four minutes to an hour or more after the poison is swallowed, death following in from ten minutes to six hours. As a rule, if the person lives for two hours after the onset of symptoms recovery may be expected.

[Illustration: Fig. 42.--Photo-micrograph of strychnine sulphate, film preparation from chloroform solution, × 50. (R. J. M. Buchanan.)]

[Illustration: Fig. 43.--Photo-micrograph of chromate of strychnine, × 50.

(R. J. M. Buchanan.)]

_Fatal Dose._--A quarter to half a grain; but large doses have been taken, followed by recovery.

[Illustration: Fig. 44.--Photo-micrograph of sulphocyanate of strychnine, × 50.

(R. J. M. Buchanan.)]

_Chemical Analysis._--The poison may fail to be detected, and this link in the scientific evidence may be wanting, as was the case in Palmer‘s trial. In that case the strychnine had been administered in _pills_; and when after death the stomach had been cut open, and the contents lost, there was little hope of discovering the poison. The non-discovery of the poison was made a strong point on the part of the defence, ignoring at the same time the fact that the stomach had been tampered with and the contents spilt. The alkaloid abstracted from the tissues or contents of the stomach by the process generally used for extraction of alkaloids, may have the following tests applied to it:

1. Scarcely soluble in water, but readily soluble in acidulated water.

2. Intensely bitter taste.

3. Not affected by sulphuric acid; but when a little peroxide of lead, or peroxide of manganese, or bichromate of potash, or ferricyanide or permanganate of potassium is added, a magnificent purple-blue colour, changing to crimson, and finally to a light red tint, is the result. The ¹/₂₀₀₀₀ part of a grain of strychnine has been stated to give this reaction.

4. The physiological test consists in introducing a small quantity of the suspected substance under the skin of a frog, and noting whether or not the animal suffers from tetanic spasms.

5. _The Galvanic Test._--Place a solution of strychnine, say one part of strychnine in 15,000 of water, in a slight depression in a piece of platinum foil, and allow the mixture to evaporate. When dry, moisten the spot with sulphuric acid, connect the foil with a positive pole of a single-cell Grove‘s battery, and then touch the acid solution with the negative pole. A violet colour will be at once produced, remaining permanent.

6. _Bloxam‘s Test._--To the solid alkaloid in a porcelain dish a drop or two of strong nitric acid is added and gently heated; on adding a small quantity of potassium chlorate a scarlet colour is produced. Ammonia changes this colour to brown and a brown precipitate falls. If the mixture he evaporated to dryness it leaves a dark green residue forming a green solution in water, changed to orange-brown with caustic potash and green again with nitric acid. This test distinguishes strychnine from any of the alkaloids which commonly occur in cases of poisoning.

7. Potassium bichromate when added to a solution of a salt of strychnine, produces a yellow crystalline precipitate of chromate of strychnine: the reaction can be done on a microscope slide and the crystals examined. On drying the crystals and then touching them with a drop of strong sulphuric acid, the purple colour changing through red to green is produced.

8. Picric acid gives a yellow crystalline precipitate of the picrate.

9. Ammonium or potassium sulphocyanate produces crystalline precipitates.

10. Ferri-cyanide of potassium produces a crystalline precipitate with solutions of salts of strychnine.

Strychnine may not be found in the body, even after death from poisoning by it, for the following reasons:

1. Smallness of the quantity taken.

2. The time which has elapsed after taking the strychnine until the symptoms commence.

3. If the careful preservation of the stomach and its contents has been overlooked.

4. The alkaloid may have been eliminated from the body before death.

_Treatment._--Evacuation of the stomach by emetics and the stomach pump, under anæsthesia, and then the administration of animal charcoal, iodide of potash, tannic acid, and tea; bromide of potassium in large doses (half an ounce), and repeated in smaller doses. Chloral should be given in five-grain doses hypodermically every ten minutes, until the convulsions are subdued. Chloroform should be inhaled for some time. Urethane is said by Anrep to be more useful than chloral, and should be given in drachm doses.

BRUCINE

This alkaloid is present along with strychnine in Nux Vomica seeds and the Ignatius bean. Cases of poisoning by it seldom occur, as the alkaloid is but little known by the public.

_Symptoms._--It resembles strychnine in its action but is much less poisonous. It produces death by convulsions when injected subcutaneously, but according to Brunton does not so often produce convulsions when taken into the stomach.

[Illustration: Fig. 45.--Photo-micrograph of crystals of brucine sulphate, × 50.

(R. J. M. Buchanan.)]

[Illustration: Fig. 46.--Photo-micrograph of crystals of brucine sulphate, × 50.

(R. J. M. Buchanan.)]

_Chemical Analysis._--The alkaloid may be extracted from organic admixture by the usual methods. Its reactions to special tests are as follows:

1. If nitric acid be added to the solid alkaloid, or in aqueous solution, a bright red colour is produced which changes to yellow on heating. The addition of stannous chloride or sulphide of ammonium to the acid solution after cooling changes it to violet; the colour is discharged by excess of the stannous chloride. If the red acid solution be largely diluted with water, a yellow precipitate falls, soluble in dilute hydrochloric acid. If the filtrate from the yellow precipitate be neutralised by ammonia and calcium chloride added, a precipitate of calcium oxalate forms, insoluble in acetic but soluble in hydrochloric acid. This reaction is peculiar to brucine.

2. With sulphuric acid and potassium bichromate a deep orange-red colour is produced.

3. Sulphomolybdic acid gives an orange-red or purplish-red colour, changing to blue.

4. _Blyth‘s Test._--If methyl iodide be added to a solution of brucine in strong alcohol, circular rosettes of crystals form in a few minutes. Strychnine does not give this reaction.

_Treatment._--Same as for strychnine.