Barite

“ Barium is another metal which does not occur in its native state in Nature. It has only been isolated as a yellow powder, which, exposed to air or water, soon changes to one of the oxides. Both barium and its compounds are peculiar in causing a green color, whenever exposed to the flame. Two of its compounds are fairly abundant, the sulphate, barite, and the carbonate, witherite. ”

“ Artificially-prepared barium sulphate is used as a pigment, Permanent White, also in the paper industry and in vulcanizing rubber. Other salts of barium of importance are barium chloride, barium nitrate, and barium carbonate, used in pyrotechny and in glass manufacture.
Barytes (American Barite) , a rhombic mineral consisting of barium sulphate (specific gravity 4.5) occurring in veins and extensive masses as a subsequent deposit in various rocks. Colourless to brownish, the colourless massive examples being in great demand as a substitute for white lead in paint and for other purposes. ”

“ Baria.] (Chem.) An oxide of barium (or barytum) ; a heavy earth with a specific gravity above 4.
BaÏry¶tes (?) , n. [Gr. ? heavy: cf. Gr. ? heaviness, F. baryte.] (Min.) Barium sulphate, generally called heavy spar or barite. See Barite.
BaÏryt¶ic (?) , a. Of or pertaining to baryta.
BaÏry¶toÐcal¶cite (?) , n. [Baryta + calcite.] (Min.) A mineral of a white or gray color, occurring massive or crystallized. It is a compound of the carbonates of barium and calcium.
Bar¶yÏtone, Bar¶iÏtone (?) , a. [Gr. ?; ? heavy + ? tone.] 1. (Mus.) Grave and deep, as a kind of male voice. ”

“ Barytes, or Heavy Spar
The mineral known as heavy spar occurs in very large quantities and in numerous localities. It forms rhombic crystals, which are very often extremely well developed and form flat plates of considerable size. A remarkable peculiarity of this mineral is its high specific gravity, which is due to the barium content. It is found native in all colours, white being the most common.
Chemically, heavy spar is barium sulphate, BaSO4. It can be used as a pigment per se, but only when prepared artificially, the trade name for the product being permanent white, or blanc fixe. ”

“ After the administration per os, much of the barium must be carried off in the diarrheal stools. A number of deaths in horses have been attributed to the use of this agent. No doubt the presence of sulphates, etc., derived from the food would render the barium insoluble in the gastro-intestinal tract, and this would explain the lack of poisonous action in certain of the cases in which large doses of barium proved harmless.
Husard and Biron administered daily doses of 8 grams of barium chlorid to one horse, and the same amount of barium carbonate to a second horse, for several days. ”

“ Barium carbonate may be fed in the form of dough composed of four parts of meal or flour and one part of the mineral. A more convenient bait is ordinary oatmeal with about one-eighth of its bulk of the mineral, mixed with water into a stiff dough. A third plan is to spread the barium carbonate upon fish, toasted bread (moistened) , or ordinary bread and butter. The prepared bait should be placed in rat runs, about a teaspoonful at a place. If a single application of the poison fails to kill or drive away all rats from the premises, it should be repeated with a change of bait. ”

“ The contents of the stomach are coloured with litmus, and barium carbonate added until the fluid is no longer acid (as shown by the disappearance of the red colour) ; then the contents are evaporated to dryness in a platinum dish, and ignited at a dull red heat; complete burning to an ash is not necessary. After cooling, the burnt mass is repeatedly exhausted with boiling water and filtered; the chloride of barium is precipitated from the filtrate by means of dilute sulphuric acid; the barium sulphate filtered off, washed, dried, and, after ignition, weighed ”

“ Barium forms numerous salts, which are all either colourless or white, except a few, whose acids are coloured, as the chromate, manganate, &c. Some of them are soluble in water; one or two only are soluble in alcohol, and that very sparingly; and (with the exception of the sulphate) they are all extremely poisonous. They may be prepared by saturating solutions of the acids with either baryta-water, or carbonate of barium; and some of them may be prepared by double decomposition. ”

“ Witherite is readily altered to barium sulphate by the action of water containing calcium sulphate in solution, and crystals are therefore frequently encrusted with barytes. It is the chief source of barium salts, and is mined in considerable amounts in Northumberland. It is used for the preparation of rat poison, in the manufacture of glass and porcelain, and formerly for refining sugar. ”

“ The metallic base of these salts is barium. It is a white, malleable, and fusible metal, readily oxidizing in air, and decomposing water at common temperature. The pure baryta, oxide of barium, is used for the production of peroxide of hydrogen, which is much recommended as a medicinal reagent, and employed in the arts for bleaching animal tissue, and converting brown into blond hair. The oxide, or caustic baryta, rivals, in caustic properties, potash, soda, and ammonia. ”

“ The baryta is mixed with a portion of hydrate of calcium or of magnesium, and the mixture being placed in an appropriate earthen tube heated to dull redness, is oxidised by passing a current of dry atmospheric air over it. As soon as the oxidation is complete, the tube is connected with the gas-holder, and a jet of steam allowed to act upon it; this reconverts the peroxide of barium into hydrate of barium, the excess of oxygen being given off and collected in the gas-holder. ”

“ Barium occurs chiefly in the form of barytes or heavy spar, BaSO4, and witherite, BaCO3, and to a less extent in baryto-calcite, baryto-celestine, and various complex silicates. The metal is difficult to isolate, and until recently it may be doubted whether the pure metal had been obtained. Sir H. Davy tried to electrolyse baryta, but was unsuccessful; later attempts were made by him using barium chloride in the presence of mercury. In this way he obtained an amalgam, from which on distilling off the mercury the barium was obtained as a silver white residue. ”

“ The sulphate of baryta is the only compound which occurs in sufficient abundance to be an economical source of the other barium compounds, and the enormous though illegitimate use of this substance in the adulteration of white lead, is so far fortunate as to render it an easy matter to obtain it in any required quantity, already in a state of fine powder which is so desirable in chemical operations. ”

“ The amount of barium found in various species of loco plants will no doubt vary, and perhaps the pharmacological test on rabbits as the writer has used it may have to be modified for such plants, so that at present the wisest plan to test these plants is to determine their barium content and also make the physiological test, as has been proposed, and if the barium content runs low, say below 0.11 per cent of the ash, in plants yielding from 12 to 18 per cent of ash, then to increase the number of feedings on the rabbit. ”

“ Barium carbonate.—One of the cheapest and most effective poisons for rats and mice is barium carbonate. This mineral has the advantage of being without taste or smell. It has a corrosive action on the mucous lining of the stomach and is dangerous to larger animals if taken in sufficient quantity. In the small doses fed to rats and mice it would be harmless to domestic animals. Its action upon rats is slow, and if exit is possible the animals usually leave the premises in search of water. ”

“ In pharmacy, &c., chiefly to prepare barium salts. In chemistry, to separate certain metallic oxides when occurring together in solutions. In the arts, as a base for certain delicate colours, as an ingredient in plate-glass, in the manufacture of beet sugar, &c. It is not used in medicine. It is extremely poisonous.
Barium, Bisulphide. This substance may be obtained as a fine yellow-coloured product by shaking a solution of barium chloride with a mixture of ammonium sulphide and carbon disulphide. It is insoluble in alcohol, soluble in water, and rapidly dissolved by slightly acidulated water. ”

“ When finely pounded and mixed with oatmeal, carbonat of barytes has been found an efficacious poison for rats.
196. SULPHAT of BARYTES is a mineral formed by the combination of sulphuric acid (24) with barytes.
It sometimes occurs in a state of powder, frequently in shapeless masses, and often crystallized: the primitive form of its crystals being a four-sided prism. It is not soluble in any other than sulphuric acid.
With us sulphat of barytes is of no use in the arts. The Chinese, however, employ it as an ingredient in the composition of porcelain ”

“ The only symptom noted was diarrhea. The animal died on the fifth day. In other words, after feeding small doses of barium salts for several days acute symptoms suddenly set in, showing a cumulative action. This cumulative action has been noted on man. [193]
[Pg 61]
Onsum [194] fed a medium-sized rabbit daily with small doses of barium carbonate, beginning with 20 milligrams. When the total amount reached 0.19 grams the rabbit died. The animal before death showed paralysis, respiratory disturbances, and fall in temperature. ”

“ Fractions 2, 3, and 4 were treated in an exactly similar way, the barium salts obtained and the weight and percentage of barium sulphate being shown in the following table:—
Calculating the fractions 1 and 2 as mixtures of barium butyrate and acetate, and fractions 3 and 4 as mixtures of barium acetate and formate, we may summarise the results thus:—
or as free acids:—
Proceeding now to (3) non-volatile bodies, we find these to consist of (1) acids, and (2) soluble carbohydrates. For examination, the remaining 4 litres of experimental drench were evaporated down to 1 litre and filtered ”

“ The pure earth is prepared exactly like baryta, from either the carbonate or the sulphate. It is a grayish-white powder, infusible in the furnace, of a specific gravity approaching that of baryta, having an acrid, burning taste, but not so corrosive as baryta, though sharper than lime. It becomes hot when moistened, and slakes into a pulverulent hydrate, dissolves in 150 parts of water at 60°, and in much less at the boiling point, forming an alkaline solution called strontia water, which deposits crystals in four-sided tables as it cools. ”

“ Drop into the first portion, muriate of barytes; wash the precipitate, collect it, dry it at a red heat upon platina foil, and weigh it; digest it in nitric acid, dry it, and weigh it again. The loss of weight indicates the quantity of carbonate of barytes which the precipitate contained. The residual weight is sulphate of barytes; the carbonic acid in the water is equivalent to 0,22 of the weight of the carbonate of barytes; the sulphuric acid to 0,339 of the weight of the sulphate of barytes. ”

“ The fact that treatment of the loco-weed extract with a few drops of sulphuric acid, which will remove the barium, renders these extracts harmless, and even apparently nutritious, would suggest the theoretical antidotal treatment to be with sulphates, in the form, perhaps, of epsom salts, but perhaps alkaline bicarbonates may be present in the stomach, either due to lessened acidity of the stomach or from drinking alkaline waters, in which case the precipitation of the barium by sulphates would presumably be interfered with, and thus the treatment be rendered ineffectual. ”

“ The post-mortem examinations in cases of acute experimental barium poisoning, according to Schedel, [220] show punctiform or large hemorrhagic effusion in the fundus ventriculi [221] and in the large and small intestines, contraction of the bladder, and hemorrhage into the walls of the bladder and uterus. The heart is usually found relaxed or the left ventricle contracted in systole, while the right is relaxed. Only once were ecchymoses under the endocardium seen. The liver and kidneys showed nothing special. ”

“ The examination of this fluid for barium might, however, be [Pg 68] misleading, as the large amount of proteids would unquestionably interfere with the determination of this amount of barium, unprotected by other salts and silica, so that this side of the investigation was not pursued. Control feedings with an emulsion of one-half gram each of pepsin and pancreatin proved inactive. ”

“ Commercial chloride of barium thus purified is probably the most convenient source of the other compounds of barium when required pure. Thus pure carbonate of baryta may be prepared from it by precipitation with carbonate of ammonia, or with carbonate of soda, which is free from silica, sulphuric acid and phosphoric acid.15
14 It may be that leaden pans are used for the evaporation or cry­stal­li­za­tion of the commercial chloride of barium, which would sufficiently account for the presence of lead in the product. ”

“ In that case the most convenient method of analysis is to add a little nitric acid, which will dissolve any carbonate of baryta that may have been formed,—to filter and then throw down the whole baryta in the form of sulphate, by means of the sulphate of soda,—and to collect the precipitate, and calcine it with charcoal for half an hour in a platinum spoon or earthen crucible, according to the quantity. A sulphuret of baryta will thus be procured, which is to be dissolved out by boiling water, and decomposed after filtration by muriatic acid. A pure solution is thus easily obtained. ”