Barium

BARIUM (from Greek barys-heavy), a diatomic metal, atomic weight 137.37, chemical symbol Ba, occurs in nature only in the form of salts, mainly as the sulfate (heavy spar) and carbonate (witherite); in insignificant quantities barium salts are found in sea water and some mineral springs. All barium salts, soluble in water or dilute acids, are poisonous, small doses already acting strongly on muscular elements. In the stomach and intestines barium salts are absorbed with difficulty but strongly excite the musculature, causing violent peristalsis (vomiting, colics, diarrhea) of myogenic origin, since peristalsis is observed even after preliminary atropinization. Barium salts apparently have no action on the brain (Kravkov); at the same time the excitability of the spinal and medulla oblongata (Cushing) is increased. Blood pressure rises strongly, heart rate first increases, then slows, individual heart contractions are intensified, vessels constrict due to action on the muscular elements of the vessel walls (Brodie).-White Barium (Barium chloratum), BaCl2, crystalline powder in the form of colorless rhombic tablets, odorless, unpleasant, sharp taste, is prescribed 0.02-0.05 per dose (0.1-0.15 per day) for 2-4 days in diseases of the heart, in place of digitalis.-Sulphur Barium (Barium sulfuratum), BaS, white, yellowish or reddish powder, soluble in water, is a component of some depilatories (see).-Sulphuric Barium (Barium sulfuricum), BaSO4, white, insoluble in water and dilute acids, non-poisonous powder; is applied in a quantity of 50-100-150 g mixed with semolina porridge during radioscopic examination of the stomach and intestines; it must be absolutely pure, without the slightest admixture of other soluble barium salts, to avoid the possibility of poisoning (F VII).-Carbonic Barium (Barium carbonicum), BaCO3, white powder without odor and taste, very slightly soluble in water; is used as poison for rats and mice.-Barium water (Aqua Barytae), solution of 1 part of crystalline hydrate of barium oxide in 29 parts of water, clear, colorless liquid; was formerly applied against scrofula.-Signs of barium poisoning: slowing of pulse, salivation, vomiting, colics, diarrhea. Antidotes: washing out the stomach with Glauber's salt solution (10 g per liter of water), enemas from Glauber's salt solution, atropin subcutaneously; for convulsions - hot bottles, chloroform or chloral hydrate; bed rest.

L. Medvedkova. Discovery of barium in legal cases. The use of carbonic barium and other soluble barium salts for poisoning mice gave occasion to human poisonings. Cases of poisoning were observed during the use of sulphuric barium (completely non-poisonous) in radioscopic examination, containing soluble barium salts in the organism. Upon the destruction of organic substances (see Poisons) barium is obtained, mainly in the form of sulphuric barium, which by fusion with soda and sodium nitrate (to remove residues of organic substances) is converted into carbonic barium; the latter, after washing, dissolves in HCl. In other cases barium is separated upon heating the liquid (upon precipitation of metals of groups V, IV and III of analysis) with dilute sulphuric acid and is converted into a soluble state.-Reaction: a drop of solution on a watch glass with a drop of dilute sulphuric acid gives a white turbidity or precipitate, insoluble from caustic soda, from ammonium acetate and not blackening from hydrogen sulfide (distinction from lead). Potassium chromate gives a yellow precipitate, insoluble from caustic soda.-Testing sulphuric barium on soluble salts. Sulphuric barium in the quantity applied during radioscopic examination (100-200 g mixed with porridge and kisel) is first treated with distilled water, then with dilute hydrochloric acid. Both extracts are evaporated to dryness, residues are dissolved in a few drops of water (with larger residues - in a larger quantity), and the resulting solutions are tested for barium as described above. For quantitative determination of barium a precipitate is made with a definite volume of titrated sulphuric acid solution, and the excess of acid is titrated with caustic soda (indicator-methyl-orange). From the point of view of hygiene, barium is of interest only in relation to compounds soluble in water - Ba(OH)2 and BaCl2, as well as soluble in acids - BaCO3 and BaS, which, entering the stomach in large doses, can cause severe poisonings, which most often occurs in chemical production. For instance, Kipper in 1926 observed a case of severe poisoning of a worker after several days of work in an atmosphere of dust containing barium oxide and carbonate. Not only acute, but also chronic poisoning with barium carbonate is possible in workshops where 'witherite' is ground, i.e. BaCO3 (Lemann). Pneumoconiosis was also described in workers during the grinding of heavy spar, i.e. BaSO4 (Fiori), as well as conjunctivitis and corneal ulcers in workers in contact with barite (Gerard). During the manufacture of barium salts and their processing, severe poisonings of workers by poisonous gases (H2S, nitrogen oxides) sometimes occur.