Antimony. This is a bluish-white, lustrous, semi-crystalline, extremely brittle metal, of about 6.7 specific gravity; imparts brittleness to alloys; inflammable at high temperature; melts just under redness, 810° Fahr., fumes, boils, and volatilizes at a white heat, and when suddenly exposed to the air, inflames and is converted into teroxide of antimony, which is deposited in beautiful crystals. Antimony dissolves in hot hydrochloric acid, forming terchloride of antimony ; nitric acid converts it into antimonic acid. This metal is obtained principally from France and Germany. Gold, when exposed to the vapors of antimony, loses its ductility and malleability, and becomes as brittle as antimony itself.

3340. Tests for Antimony

3340. Tests for Antimony. An acid solution of antimony gives, in combination with sulphuretted hydrogen, an orange-red precipitate, sparingly soluble in ammonia, but readily soluble in pure potassa and alkaline sulphurets. Hydrosulphuret of ammonia throws down from the acid solution an orange-red precipitate, readily soluble in excess of the precipitant, if the latter contain sulphur in excess; and the liquor containing the re-dissolved precipitate gives a yellow or orange-yellow precipitate on the addition of

BISMUTH—ALLOYS.

an acid. Ammonia, and potassa, and their carbonates (excepting in solutions of tartar emetic) give a bulky white precipitate; that from ammonia being insoluble in excess of the precipitant; that from potassa readily so; while those from the carbonate are only soluble on the application of heat.

3341. To Estimate the Purity of Antimony

3341.      To Estimate the Purity of Antimony. Treat pulverized antimony with nitric acid; this oxidizes the antimony, and leaves it in an insoluble state, whilst it dissolves the other metals. Collect the oxide on a filter, wash, dry, ignite, and weigh it. This weight, multiplied by .843, gives the weight of pure metal in the sample examined. If this has been previously weighed, the percentage of pure metal is easily arrived at.

3342. To Obtain Metallic Antimony

3342.    To Obtain Metallic Antimony. Mix together 16 parts sulphuret of antimony and 6 parts cream of tartar, both in powder; put the mixture, in small quantities at a time, into a vessel heated to redness; when reaction ceases, fuse the mass, and, after 15 minutes, pour it out and separate the metal from the slag. The product is nearly pure.

Or: Equal parts of protoxide of antimony and bitartrate of potassa (cream of tartar); mix and fuse as above, and pour the metal into small conical moulds.

Or: 8 parts sulphuret of antimony, 6 parts cream of tartar, and 3 parts nitre. Treated as above.

Or: 2 parts sulphuret of antimony and 1 part iron filings; calcine at a strong heat in a covered crucible.

3343. To Obtain Commercial Antimony

3343.    To Obtain Commercial Antimony. Fuse together 100 parts sulphuret of antimony, 40 parts metallic iron, and 10 parts dry crude sulphate of soda. This produces from 60 to 65 parts of antimony, besides the scoriae or ash, which is also valuable.