TRISNITRATE OF BISMUTH.

647

tlie list of the materia raedica of the Dublin Pharmacopceia, but for what reasonI cannot understand, since it is never used in medicine. The bluish white pre-cipilate obtained by adding a Solution of the neutral acetate of copper to a Solu-tion of albumen, consists of albumen 90-81, and deuto-acetate of copper 9-19. Itis soluble in excess of Solution of either acetate of copper or of albumen. (Las-saigne, Joum. de Chim. Med. t. vi. 11« Ser. p. 305.)

Order XXIII.— BISMUTH AND ITS COMPOUNDS.

1. BISMUTIIUM, L. E. D. (U. S.)—BISMUTH.

History. —This metal is first mentioned by Agricola, in 1529. It has beentermed Marcasita, Tectum Argenti, or, by the Germans, Wismuth. " The oldminers called it Wismuth," says Matthesius, " because it blooms as a beautifulmeadow, {Wiesematte,) on which variegated flowers of all kinds are glittering."(Schwartze, Pharm, Tabellen.)

Natural History. —Bismuth occurs only in the mineral kingdom. It is foundin Cornwall, Saxony, Bohemia, &c. It is met with in the metallic State nearlypure, [Nalive Bismuth,) and in combination with sulphur and with oxygen.

Preparation. —It is chiefly obtained from native bismuth by melting the metalout of its gangue.

Propbrtibs. —It is a reddish white metal, without taste or smell, composed ofbrilliant broad plates, and readily crystallizable in cubes or regulär octohedrons.Its sp. gr. is 9'83 to 9'88. It is moderately hard, brittle, pulverizable, fusibleat 476° F. When strongly heated in the air it takes fire, and burns with a faintblue flame, emitting a yellow srnoke (the oxide.) In close vessels it may bevolatilized. Its equivalent is 72.

Characterislics. —It is distinguisbed by its brittleness (see p. 648,) its readyfusibility, its solubility in nitric acid, and by the characters of the nitric Solution,which throws down a white precipitate on the addition of water, and a black onewhen hydrosulphuric acid or the hydrosulpbates are added to it.

Purity. —Copper may be detected by precipitating the nitric Solution with am-monia; the supernatant liquor is blue if copper be present.

It is dissolved by diluted nitric acid; when subnitrale of bismuth is prccipatcd from thiss-olution by ammonia, the liquor is free from colour. Its specific gravity is 9-8. Pti. Land.

Its powder is entirely soluble in nitric acid with the aid of heat; and the Solution is colour-less or nearly so, änd deposites a white powder when mueh diluted with cold water. Ph. Ed.

Physiological Effects and Uses. —In the metallic State, bismuth is inert,only use is in the preparation of the trisnitrate.

Its

3. BISMUTHI TRISNI'TRAS, L.— TRISNITRATE OF BISMUTH.(Bisnmtham album, E. —Bismutlii Subnitras, i>.)—[U. S.j

History. __This Compound was first prepared by Lemery. It has had various

appellations, such as Pearl White, Magister;/ of Bismuth (also a name for sub-muriate of bismuth,) Spanish White, Sub-nilrate or Tctarto-nitrate of bismuth.

Preparation. __AU the British Colleges give directions for the preparation of

this salt.

The London Golteo-e orders of Gismuth, gj.; Nitric Acid,fgiss.; Distilled Water, Oiij. Mixa fluid ounce of the water with the Nitric acid, and dissolve the Bismuth in thcin ; theo pouroff the Solution. To this add the rest of the water, and set by tbat the powder may subside.Afterwards, the supernatant liquor being poured off, wash the Trisnitrate of Bismuth withdistilled water, and dry it with a gentle heat. [This is essentially the direction of the U. S.Phar.l

The process of the Edinburgh College is essentially similar. lhe precipitate [the Trisni-