502
ELEMENTS OF MATERIA MEDICA.
re-action of three equivalents or 216 parts of bismuth, on four equivalentsor 216 parts of nitric acid. One equivalent or 30 parts of binoxideof nitrogen are evolved, and three equivalents or 402 parts of nitrate ofbismuth formed.
Ueq.Binox.Nitrog. 30-
?3 eq. Oxygen_24-
. 216-
. 162-
=.3 eq. Ox.Bism 1 ' .240
RESULTS.
leq.Binox.Nitrog. 303 eq.Nitrate Bism.402
When nitrate of bismuth is mixed with water, two bismuthic salts areproduced ; a soluble supersalt ( ternitrate), and an insoluble subsalt (tris-nitrate ).
REAGENTS.
1 eq. Nitrate Bismuth = 334 ---—_
( 2 eq. Nitric Acid ..3 eq. Nitrate Bismuth = 402-! 1 eq. Nitric Acid ..
( 3 eq. Oxide Bismuth
RESULTS.
108_.54 >240 S
-j e( ^ Trisnitrate Bismuth = 294
Properties. —It is a dull white, inodorous, tasteless powder , whichconsists of very tine silky needles. It is nearly insoluble in water, but isreadily dissolved by nitric acid. By exposure to light it becomes greyish.
Characteristics. — Ilydrosulphuric acid, or the hydrosulphates, ;blacken it, by forming the sulphuret of bismuth. It dissolves in nitric -acid without effervescence. Heated on charcoal by the blowpipe flameit gives out nitrous acid, and yields the yellow oxide of bismuth ; and, bya continuance of the heat, the oxide is reduced, globules of metallicbismuth being obtained, which may be readily distinguished from globulesof lead by their brittleness ; for, when struck sharply by a hammer on an 1anvil, they fly to pieces : from antimony they are distinguished by their 'solubility in nitric acid. ;
Composition.— Its composition, according to Mr. Phillips {Phil. Mag. jDec. 1830, p. 409,) is as follows :— j
Etp Eq.Wt. PerCent. R. Phillips.
Oxide of Bismuth. 3 . . . . 240 .... 81-(>4 .... 81-92
Nitric Acid. 1 ■ ■ ■ ■ 54 ... ■ 18-36 .... 18'28
Trisnitrate of Bismuth ... 1 ... . 294 .... 100-00 . . • . lOO'OO
Purity. —Its freedom from any carbonate (as of lead) is distinguishedby its solution in nitric acid without effervescence. Sulphuric acidadded to the solution throws down a white precipitate, if lead be present. 1Physiological Effects. [a) On animals. —It acts as a local irritant iand caustic poison. Moreover it appears to exercise a specific influenceover the lungs and nervous system (Orfila, Toxicol. Gen.)
{b.) On man. —In small doses it acts locally as an astringent, diminish-ing secretion. On account of the frequent relief given by it in painful Iaffections of the stomach, it is supposed to act on the nerves of this |viscus as a sedative. It has also been denominated tonic and antispas- jmodic, Vogt ( Pharmakodynamik , i. 288, 2“ Aufl.) says, that when usedas a cosmetic, it has produced a spasmodic trembling of the muscles ofthe face, ending in paralysis.
Large medicinal doses disorder the digestive organs, occasioning pain,vomiting, purging, &c.; and sometimes affecting the nervous system, andproducing giddiness, insensibility, cramps of the extremities, &c.
The following is the only reported case of poisoning with it. A mantook two drachms by mistake, and died therefrom on the ninth day. In