_Post-Mortem Appearances._--Stomach and duodenum reddened, with deposits of sulphur. Lungs congested.

_Treatment._--Chloride of sodium or lime in dilute solution, and ordinary treatment for irritant poisoning.

_Fatal Period (Shortest)._--Fifteen minutes.

XVIII.--BARIUM SALTS

=Chloride of Barium= occurs crystallized in irregular plates, like magnesium sulphate, soluble in water and bitter in taste. =Carbonate of Barium= is found in shops as a fine powder, tasteless and colourless, insoluble in water, but effervescing with dilute acids, and readily decomposed by the free acids of the stomach. =Nitrate of Barium= occurs in octahedral crystals, soluble in water.

_Method of Extraction from the Stomach._--Dialysis as for other soluble poisons.

_Tests._--Precipitated from its solutions by pota.s.sium carbonate or sulphuric acid. Burnt on platinum-foil, it gives a green colour to the flame.

_Symptoms._--Besides those of irritants generally, violent cramps and convulsions, headache, debility, dimness of sight, double vision, noises in the ears, and beating at the heart. The salts of barium are also cardiac poisons.

_Post-Mortem Appearances._--As of irritants generally. Stomach may be perforated.

_Treatment._--Wash out stomach with a solution of sodium or magnesium sulphate, or of alum, and give stimulants by the mouth and hypodermically.

XIX.--IODINE--IODIDE OF POTa.s.sIUM

=Iodine= occurs in scales of a dark bluish-black colour. It strikes blue with solution of starch, and stains the skin and intestines yellowish-brown. Liquid preparations, as the liniment or tincture, may be taken accidentally or suicidally.

_Symptoms._--Acrid taste, tightness of throat, epigastric pain, and then symptoms of irritant poisons generally. Chronic poisoning (iodism) is characterized by coryza, salivation, and lachrymation, frontal headache, loss of appet.i.te, marked mental depression, acne of the face and chest, and a petechial eruption on the limbs.

_Post-Mortem Appearances._--Those of irritant poisoning with corrosion, and staining of a dark brown or yellow colour.

_Treatment._--Stomach-pump and emetics, carbonate of sodium, amylaceous fluids, gruel, arrowroot, starch, etc.

_a.n.a.lysis of Organic Mixture containing Iodine._--Add bisulphide of carbon, and shake. The iodine may be obtained on evaporation as a sublimate. It will be recognized by the blue colour which it gives with starch.

=Iodide of Pota.s.sium.=--Colourless, generally opaque, cubic crystals, soluble in less than their weight of cold water.

_Symptoms._--Not an active poison, but even small doses sometimes produce the effects of a common cold, including those symptoms already mentioned as occurring with iodine.

_a.n.a.lysis._--Iodide of pota.s.sium in solution gives a bright yellow precipitate with lead salts; a bright scarlet with corrosive sublimate; and a blue colour with sulphuric or nitric acid and starch.

XX.--PHOSPHORUS

=Phosphorus= is usually found in small, waxy-looking cylinders, which are kept in water to prevent oxidation. It may also occur as the amorphous non-poisonous variety, a red opaque infusible substance, insoluble in carbon disulphide. Ordinary phosphorus is soluble in oil, alcohol, ether, chloroform, and carbon disulphide; insoluble in water.

It is much used in rat poisons, made into a paste with flour, sugar, fat, and Prussian blue. Yellow phosphorus is not allowed to be used in the manufacture of lucifer matches, and the importation of such is prohibited. In 'safety' matches the amorphous phosphorus is on the box.

_Symptoms._--At first those of an irritant poison, but days may elapse before any characteristic symptoms appear, and these may be mistaken for those of acute yellow atrophy of the liver. The earliest signs are a garlicky taste in the mouth and pain in the throat and stomach. Vomited matter luminous in the dark, bile-stained or b.l.o.o.d.y, with garlic-like odour. Great prostration, diarrhoea, with b.l.o.o.d.y stools. Harsh, dry, yellow skin, purpuric spots with ecchymoses under the skin and mucous membranes, retention or suppression of urine, delirium, convulsions, coma, and death. Usually there are remissions for two to three days, then jaundice comes on, with enlargement of the liver; haemorrhages from the mucous surfaces and under the skin; later, coma and convulsions. In chronic cases there is fatty degeneration of most of the organs and tissues of the body. The inhalation of the fumes of phosphorus, as in making vermin-killers, etc., gives rise to 'phossy-jaw.'

_Post-Mortem Appearances._--Softening of the stomach, haemorrhagic spots on all organs and under the skin, fatty degeneration of liver, kidneys, and heart, blood-stained urine, phosph.o.r.escent contents of alimentary ca.n.a.l.

_Treatment._--Early use of stomach-pump and emetics, followed by the administration of permanganate of pota.s.sium or peroxide of hydrogen to oxidize the phosphorus. Oil should not be given. Sulphate and carbonate of magnesium, mucilaginous drinks. Sulphate of copper is a valuable antidote, both as an emetic and as forming an insoluble compound with phosphorus.

_Fatal Dose._--One grain and a half.

_Fatal Period._--Four hours; more commonly two to four days.

_Detection of Phosphorus in Organic Mixtures._--Mitscherlich's method is the best. Introduce the suspected material into a retort. Acidulate with sulphuric acid to fix any ammonia present. Distil in the dark, through a gla.s.s tube kept cool by a stream of water. As the vapour pa.s.ses over and condenses, a flash of light is perceived, which is the test.

XXI.--a.r.s.eNIC AND ITS PREPARATIONS

=a.r.s.enic= is the most important of all the metallic poisons. It is much used in medicine and the arts. It occurs as metallic a.r.s.enic, which is of a steel-grey colour, brittle, and gives off a garlic-like odour when heated; as a.r.s.enious acid; in the form of two sulphides--the red sulphide, or realgar, and the yellow sulphide, or orpiment; and as a.r.s.enite of copper, or Scheele's green. It also exists as an impurity in the ores of several metals--iron, copper, silver, tin, zinc, nickel, and cobalt. Sulphuric acid is frequently impregnated with a.r.s.enic from the iron pyrites used in preparing the acid. It is a const.i.tuent of many rat pastes, vermin or weed killers, complexion powders, sheep dips, etc.

=a.r.s.enious Acid= (White a.r.s.enic, Trioxide of a.r.s.enic).--Colourless, odourless, and almost tasteless. It occurs in commerce as a white powder or in a solid cake, which is at first translucent, but afterwards becomes opaque. Slightly soluble in cold water; 1 ounce of water dissolves about 1/2 grain of a.r.s.enic. Fowler's solution is the best-known medicinal preparation of a.r.s.enic, and contains 1 grain of a.r.s.enious anhydride in 110 minims.

_Symptoms._--Commence in from half to one hour. Faintness, nausea, incessant vomiting, epigastric pain, headache, diarrhoea, tightness and heat of throat and fauces, thirst, catching in the breath, restlessness, debility, cramp in the legs, and convulsive twitchings. The skin becomes cold and clammy. In some cases the symptoms are those of collapse, with but little pain, vomiting, or diarrhoea. In others the patient falls into a deep sleep, while in the fourth cla.s.s the symptoms resemble closely those of English cholera. The vomited matters are often blue from indigo, or black from soot, or greenish from bile, mixed with the poison. Should the patient survive some days, no trace of a.r.s.enic may be found in the body, as the poison is rapidly eliminated by the kidneys.

In all suspected cases the urine should be examined.

The symptoms of _chronic_ poisoning by a.r.s.enic are loss of appet.i.te, silvery tongue, thirst, nausea, colicky pains, diarrhoea, headache, languor, sleeplessness, cutaneous eruptions, soreness of the edges of the eyelids, emaciation, falling out of the hair, cough, haemoptysis, anaemia, great tenderness on pressure over muscles of legs and arms, due to peripheral neuritis, and convulsions.

Pigmentation is common; the face becomes dusky red, the rest of the body a dark brown shade. This darkening is most marked in situations normally pigmented and in parts exposed to pressure of the clothes, such as the neck, axilla, and inner aspect of the arms, the extensor aspects being less marked than the flexor. The pigmentation resembles the bronzing of Addison's disease, but there are no patches on the mucous membranes, and the normal rosy tint of the lips is not altered. The skin over the feet may show marked hyperkeratosis.

The nervous system is notably affected. The sensory symptoms appear first: numbness and tingling of the hands and feet, pain in the soles of the feet on walking, pain on moving the joints, and erythromelalgia.

Then come the motor symptoms, with drop-wrist and drop-foot. The patient suffers severely from neuritis, and there may be early loss of patellar reflex. The nervous symptoms come on later than the cutaneous manifestations.

_Post-Mortem Appearances._--Signs of acute inflammation of stomach, duodenum, small intestines, colon, and r.e.c.t.u.m. Stomach may contain dark grumous fluid, and its mucous coat presents the appearance of crimson velvet. Ulceration is rare, and cases of perforation still less common, the patient dying before it occurs. If life has been preserved for some days, there is extensive fatty degeneration of the organs. There may be entire absence of _post-mortem_ signs. Putrefaction of the body is r.e.t.a.r.ded by a.r.s.enic.

_Treatment._--The stomach-pump, emetics, then milk, milk and eggs, oil and lime-water. Inflammatory symptoms, collapse, coma, etc., must be treated on ordinary principles. As an antidote, the best when the poison is in solution is the hydrated sesquioxide of iron, formed by precipitating tinctura ferri perchloridi with excess of ammonia, or carbonate of soda. This is filtered off through muslin and given in tablespoonful doses. It forms ferric a.r.s.enate, which is sparingly soluble. Colloidal iron hydroxide may be used instead. Dialyzed iron in large quant.i.ties is efficacious.

_Fatal Dose (Smallest)._--Two grains. Exceptionally, recovery from very large doses if rejected by vomiting.

_Fatal Period (Shortest)._--Twenty minutes. Exceptionally, death as late as the sixteenth day. The effects of a.r.s.enic are modified by tolerance, some persons being able to take considerable quant.i.ties. The peasants of Styria are in the habit of eating it.

_Method of Extraction from the Stomach._--The coats of the stomach should be examined with a lens for any white particles. These, if present, may be collected, mixed with a little charcoal in a test-tube, and heated. If a.r.s.enic is present, a metallic ring will be formed in the cooler parts of the tube. If this ring be also heated, octahedral crystals of a.r.s.enic will be deposited farther up the tube, and are easily recognized by the microscope. The contents of the stomach, or the solid organs minced up, should be boiled with pure hydrochloric acid and water, then filtered. The filtrate can then be subjected to Marsh's or Reinsch's process.

_Tests._--In _solution_, a.r.s.enic may be detected by the liquid tests.

(1) Ammonio-nitrate of silver gives a yellow precipitate (a.r.s.enite of silver). (2) Ammonio-sulphate of copper gives a green precipitate (Scheele's green). (3) Sulphuretted hydrogen water gives a yellow precipitate.