A crystalline metal; as met with in commerce it is generally impure.

From Bismuthum is made:

Bismuthum Purificatum. - Purified Bismuth.

Source. - Made by heating Bismuth with Nitrate of Potash.

Characters. - A crystalline metal of a greyish-white colour, with a roseate tinge.

Impurity. - Copper; giving coloured reactions.

From Bismuthum Purificatum are made: a. Bismuthi Subnitras. - Subnitrate of Bis-muth. White Bismuth. BiONO3H1O.

Source. - Made (1) by dissolving Purified Bismuth in Nitric Acid; and (2) pouring the product into Water. (1) Bi2 + 8HNO3 = 2(Bi3NO3) + 2NO + 4H1O. (2) Bi3NO3 + H1O == BiONO3 + 2HNO3.

Characters. - A heavy white powder, in minute crystalline scales; insoluble in water.

Impurities. - Carbonate of lead; giving precipitate with H1SO4 when dissolved in HNO3; arsenic; and chlorides.

Dose.- 5 to 20 gr.

Preparation. i. Trochisci Bismuthi. - 2 gr. Subnitrate of Bismuth in each, Carbonate of Lime, and the usual ingredients of a lozenge. Dose, 1 to 6.

From Bismuthi Subnitras is made: ii. Bismuthi Oxidum. - Oxide of Bismuth. Bi2O3.

Source. - Made by boiling Subnitrate of Bismuth in Solution of Soda.

Characters. - A dull lemon-yellow powder; insoluble in water, soluble in nitric acid mixed with half its volume of water.

Impurities. - As of the sulmitrate. Dose - 5 to 15 gr.

. Liquor Bismuthi et Ammonia Citratis.

Source. - Made by dissolving Purified Bismuth in Diluted Nitric Acid, adding Citric Acid, and re-dissolving the precipitate with Ammonia, as it forms.

Characters. - A colourless solution, with a saline and slightly metallic taste; neutral or slightly alkaline to test-paper; mixes with water without change. 1 fl.dr. contains 3 gr. of oxide of bismuth.

Dose. - 1/2 to 1 fl.dr.

γ. Bismuthi Carbonas. - Carbonate of Bismuth. 2(Bi2CO5)H.2O; an oxycarbonate.

Source. - Made by (1) dissolving Purified Bismuth in Nitric Acid and Water; and (2) precipitating by a solution of Carbonate of Ammonia. (1) Bi2 + 8HNO3 = 2(Bi3NO3) + 2NO + 4H1O. (2) 4(Bi3NO3) + 3(N4H16C3O8) = 2Bi2CO5 + 7CO2 + 12NH4NO3.

Characters. - A white powder, insoluble in water; soluble with effervescence in nitric acid.

Impurities. - The subnitrate, and its impurities.

Dose. - 5 to 20 gr.

Action And Uses. 1. Immediate Local Action And Uses

Externally applied in the form of powder or ointment, bismuth acts only physically on the unbroken skin, protecting it from the irritation of cold and dirt. If the surface be inflamed, as in chapped hands, chapped nipples, irritable ulcers, and eczema, it is a mild sedative and astringent, soothing and drying up the part. Accessible mucous membranes are similarly affected by bismuth, when in a condition of catarrh: thus it is used with success as a "snuff" for nasal catarrh; as an injection in gonorrhoea and leucorrhoea; and in irritability of the cervix uteri as a pessary. Bismuth is not known to be absorbed from the surface.

Internally, the local action and uses of the subnitrate of bismuth constitute all, or nearly all, that is definitely known respecting it as a remedy. In the stomach it is insoluble, and exerts the same sedative and astringent action as on the skin, whether by affecting the nerves and local installation, or by its mechanical properties, that is, by coating and protecting the mucous surface. Little or no good is to be expected from less than 20 gr. doses of the subnitrate to an adult, and these may be trebled with perfect safety. Bismuth is extensively used in this country in the treatment of pain and vomiting due to catarrh or organic disease of the stomach, such as the gastric catarrh that follows a surfeit of food or alcoholic excess, recurrent gastric ulcer, and cancer; also in some cases of so-called nervous or reflex vomiting, as in pregnancy and hysteria, where a true catarrh is often present. Bismuth may be given alone in such conditions, but is better combined, on the one hand, with alkalies, such as bicarbonate of soda, if there be much actual catarrh; or, on the other hand, with opium, if pain be the chief symptom. A combination of the subnitrate of bismuth and a variable number of grains of Pulvis Ipecacuanhae Compositus is almost a specific for the pain and vomiting of ulcer and malignant disease.

The astringent and sedative influence of bismuth on the intestines constitutes it a valuable remedy for diarrhoea in delicate persons, such as children, phthisical subjects, and those who have been exhausted by other causes. In lienteric diarrhoea, probably referable to duodenal catarrh, it is sometimes invaluable. But in the intestines, as in the stomach, the addition of opium, in however small quantity almost, greatly assists its action, and in persistent cases of diarrhoea is absolutely necessary. The same combination with Dover's powder gives excellent results. Bismuth subnitrate is partly converted into the sulphide in the bowel, which imparts a characteristic leaden-grey colour to the faeces.

2. Action In The Blood

Neither the insoluble nor the soluble (but weak) preparations of bismuth enter the blood in any quantity. Still, the metal has been detected, both here and in the tissues.

3. Specific Action

Bismuth finds its way, but very slowly, through all the organs and tissues; but no specific effect can be traced to its presence, even when it is given in doses of several drachms. The so-called effects of bismuth, of the older authorities, were certainly caused by arsenic combined with it as an impurity.

4. Remote Local Action

Bismuth has been found in the urine, and it is said, in the milk. No use is made of its remote influence, if any such exist.