Arsenic

[Fr.; Gr. arse nikon, from arsen, male, masculine, i. e. the substance which kills with masculine force.] ( Chem. and Min. ) A very soft, brittle, and eminently poisonous metal, of a steel-gray color. Symbol As. It is scattered in great abundance over the mineral kingdom, and is sometimes found in the free state, but more frequently combined, chiefly with iron, nickel, cobalt, and sulphur. It is also contained in very small quantities in many mineral springs. In order to separate A. from any of the metallic ores in which it occurs, the ore is roasted, or exposed to a current of heated air in a reverberatory furnace. A. was known in different combinations by the ancients, but has only latterly been known to be of metallic origin. It is, however, so unlike metal in many of its properties that, even now, certain French chemists consider it as belonging to the nonmetallic elements; indeed, it may be considered the connecting link between these two divisions of the elements; antimony and bismuth being closely connected with it on the one hand, and phosphorus and nitrogen on the other. A. combines with the atmospheric oxygen, forming arse nic and arsenious oxide. Metallic A. may be formed from arsenious oxide by mixing it with charcoal and sodium carbonate, and heating in a closed crucible, the upper part of which is kept cool; A. condenses in the cool part of this apparatus as a solid, with a brilliant grayish lustre. It tarnishes in the air from oxidation; it has a sp. gr. of 5-7 to 5-9, and when heated to 500° Fahren., it volatilizes as a colorle vapor without undergoing fusion, and this vapor po e es a remarkable garlic-like smell. A., when heated in the air, takes fire, and burns with a bluish flame, forming arsenious oxide, As203; when thrown into chlorine it instantly takes fire, forming A. trichloride, AsCl3. Metallic A. may be reduced to powder in a mortar, and is not considered poisonous; but when introduced into the animal system, it is in part oxidized, thus acquiring poisonous properties. A minute quantity of A. is added to lead, to diminish its cohesion, during the manufacture of shot. It is the only use to which the metal A. is applied in the arts. Its only important combinations are: arsenic and arsenious acids, q.v.; the disulphide, or realgar (q. v.), which is used in pyrotechny; and the trisulphide, or orpiment (q. v.), which is the king's yellow of the artist. A. also forms a tri hydride with hydrogen, analogous to the ammonia-like compounds formed by antimony and phosphorus. life, but, happily, the pro ce for the detection of the poison in Arsen'ic Acid, ARSENIC OXIDE. ( Chem .) This acid, discovered by Scheele, is obtained by acting upon the trioxide ( arsenious acid ) with nitric acid, evaporating to dryne , and heating to a temperature of 270°. It forms a non-crystalline white powder, which, when strongly heated, decomposes into As20, and O2. This powder is readily di olved by water, and the solution yields crys- tals of A. acid, or trihydric arsenate, H3AsO.-Arsenic acid is a more violent poison than even the arsenious. It is used in taxidermy, and in making aniline colors. Arsen'ical, a. Consisting of, or containing arsenic. Arsen'icate, v . a . To combine with arsenic. Arsenide, Arseni'uret, n. (Chem.) A compound of Arseni'uret, n. See ARSENIDE. as, for example, A. of copper , or Scheele's green, and the Schweinfurth green, which is a double arsenite and ar- senate of copper, both of which are largely used as pig- ments. All the soluble A. are deadly poisonous sub- stances, which ought to be prohibited. Wherefore, it seems proved that rooms coated with Scheele's green are detrimental to the health of human beings residing therein, from the readine with which minute particles of the poisonous pigment are detached from the walls by the slightest friction, are diffused through the room, and ultimately pa into the animal system. ARSENIDE. arsenic with an elementary substance. The Arsenvureted Arseni'ureted, a. Combined with arsenic. See hydrogen is formed by decomposing an alloy of arsenic and zinc with sulphuric acid. It is a colorle gas, po e ing a fetid odor of garlic; it acts as a most deadly poison, a single bubble of the pure gas having been known to act fatally; when cooled to -40°, it condenses to a colorle liquid. Arseniureted hydrogen burns with a bluish flame, and deposits arsenic upon a cold body held in the flame; below a red heat, it is decomposed into arsenic and hydrogen. Density 39; form . AsH3. Arseniosid'erite, n . (Min.) A mineral having fibrous concretions of a yellowish-brown color, approaching to golden, resembling cacoxenite; the fibres large and easily separable between the fingers. Lustre silky; powder yellowish-brown, rather deeper than yellow- ochre in color. Comp . Arsenic pentoxide, 37-8; iron sesquioxide, 42.1; calcium oxide, 183; water, 8-9. It occurs a ociated with manganese in France, and with erythrite at Schneeburg in Saxony. Arse'nious Acid, ARSENIOUS TRIOXIDE, WHITE AR- SENIC. (Chem.) A white substance known in commerce by the name of white arsenic , which is one of the most virulent poisons of the mineral kingdom. It frequently occurs in a native state, if not very abundantly; and it is obtained in roasting several ores, particularly those of cobalt. In the chimneys of the furnaces where this operation is conducted, it generally condenses in thick semi-transparent ma es; though sometimes it a umes the form of a powder, or of little needles, in which state it was formerly called flowers of arsenic. The A. A. red- dens the most sensible blue vegetable colors, though it turns the syrup of violets green. On exposure to the air, it becomes opaque, and covered with a slight efflorescence. Thrown on incandescent coals, it evaporates in white fumes, with a strong smell of garlic. In close ve els it is volatilized; and, if the heat be strong, vitrified. The result of this vitrification is a transparent gla , capa- ble of crystallizing in reg. octohedra, the angles of which are truncated. It is easily altered by hydrogen and carbon, which deprive it of its oxygen at a red heat, and reduce the metal, the one forming water, the other car- bonic acid, with the oxygen taken from it. It is feebly soluble in water; it di olves more readily in hydro- chloric acid, and is feebly soluble in solutions of the alkalies. Density (of vapor) 99; sp. gr. 3-6; form As03. As ordinarily sold in quantities under 10 lbs. in weight, the A : A. is required by law, in Europe, to be colored with of its weight of indigo, or of its weight of soot; the object of the admixture being to render any liquid to which the A. A. might be added with a mur- dero us intent, of a black or bluish-black hue, and thus indicate the presence of something unusual. The solu- tion of A. A. in water is recognized by three tests: 1. Hydrosulphuric acid in acid solutions produces a yellow precipitate of sulphur ide of arsenic, As.S2, solu- ble in ammonia. 2. Ammonio-sulphate of copper, an apple-green precipitate of arsenic of copper, CuAs2Os. 3. Ammonio-nitrate of silver, a yellow precipitate of arsenite of silver, Ag, As... The quantity nece ary to destroy life, of course, varies, but it is stated that 2 or 3 grains may prove fatal. Death may occur in a few hours, or after the lapse of days. A. A. has been used frequently as a slow poison, the symptoms being at- tributed to inflammation of the bowels from natural causes, but its detection is now easy. (See ARSENIC.)- A. A. has long been used as a medicine. When taken into the stomach, it is soon absorbed into the blood, and circulates with that fluid, exhibiting great power over certain diseases, especially skin diseases, as psoriasis, lepra, eczema, . It is also cla ed among the tonic minerals, and given for nervous disorders, especially those that are periodic. It has been much recommended for rheumatism; and considered as holding the foremost place among the remedies for cholera. In ague, also, and remittent fever, as well as in other disorders origi- nating from the same source, A. and quinine are our chief remedies. They are considered to act as alteratives of the blood. The usual method of administering A. is in small doses (from three to five drops) of the liquor arsenical is, largely diluted with water, twice or thrice in aday. The influence of a minute quantity of A. A. on the human frame is a very curious question. Though strange it may seem, it is a erted that in Styria it is a common thing for the peasants to take 12 to 13 grains per day of white arsenic, to improve their wind. It appears to do them no harm, as long as they relinquish the use of it gradually when they reach 50 or 60 years of age. They begin by taking a single grain per day, increasing the dose until they arrive at their maximum. If the doses are discontinued suddenly, death, with all the symptoms of arsenical poisoning, is the result. Ar's enite, n. [Fr. arsenite ] A salt resulting of the union of arsenious oxide with a base. The general for mula of the arsenites is MASO2. The alkaline A. are soluble in water; those of the metals of the alkaline earths, and heavy metals, are insoluble in water. Some of them are employed in the arts and in manufacturing; Arsen'olite, n . ( Min .) Anisometric mineral; octohedronal; of vitreous or silky lustre; color white with an occasional yellowish or reddish tinge. Streak white, pale yellowish. Transparent, opaque; astringent, sweetish taste. Comp. Oxygen 24-24, arsenic 75-76-100. It accompanies silver and lead ores, arsenical iron, cobalt, antimony, nickel, ., as a result of the decomposition of arsenical ores; and is found in Nevada and California. Arseno'pyrite, or MISPICKEL, n. ( Min .) An orthorhombic mineral. Lustre metallic; silver-white, approaching to steel-gray, in color; dark grayish-black streak; uneven in fracture, and brittle. Comp . Arsenic 46-0, sulphur 19-6, iron 34-4-100. Part of the iron is sometimes replaced by cobalt. It is principally found in crystalline rocks, and is generally a ociated with silver, lead, and tin ores, and tin pyrite, chalcopyrite, and blende. It is also found in serpentine. It occurs in many parts of the U. States and S. America.