624s

Preparations and Compositions. Part IIL

Trochisci nitratis potass.?-:. Ed.Troches of Nitrate of Potass.Take of

Nitrate of potass, one part;Double refined sugar, three parts.Rub together to powder, and form them, with mucilage ofgum tvagacanth, into a mass, to be divided into troches.

This is a very agreeable form for the exhibition of nitre;though, when the salt is thus taken without any liquid, (if thequantity be considerable), it is apt to occasion uneasiness a-bout the stomach, which can only be prevented by large di-lution with aqueous liquors.

Chap. XXXIX.—PILLS.

This form is peculiarly adapted to those drugs which ope-rate in a small dose, and whose nauseous and offensive tasteor smell require them to be concealed from the palate.

Pills should have the consistence of a firm paste, a roundform, and a weight not exceeding five grains. Essential oilsmay enter them in small quantity : deliquescent salts are im-proper. Efflorescent salts, such as carbonate of soda, shouldbe previously exposed to the air until they fall to powder : de-liquescent extracts should have some powder combined withthem. The mass should be beaten until it become perfectlyuniform and plastic. Powders may be made into pills withextracts, balsams, soap, mucilages, bread crumb, &c.

Gum-resins, and inspissated juices, are sometimes softenough to be made into pills, without addition: where anymoisture is requisite, spirit of wine is more proper than sy-rups or conserves, as it unites more readily with them, anddoes not sensibly increase their bulk. Light: dry powders re-quire syrups or mucilages: and the more ponderous, as themercurial and other metallic preparations, thick honey, con-serve, or extracts.

Light powders require about half their weight of syrup, orabout three-fourths their weight of honey, to reduce them in-to a due consistence for forming pills. Llalf a drachm of themass will make five or six pills of a moderate size.