Syn. Infusion de Quinquina (F.), Chinainfusum (G), Infuso di China (I.).

"Take of lance-leaved cinchona1, bruised, an ounce; boiling distilled water, a pint. Macerate for two hours in a lightly-covered vessel, and strain." - Lond.

" Triturate the bark with a little of the water, and add the remainder during the trituration. Macerate for twenty-four hours, with frequent agitation, and decant the pure liquor."- Dub.

This infusion contains a portion of cinchonia, the febrifuge principle of this bark. Its strength is considerably augmented 'when f 3 j. of diluted sulphuric acid is added to the boiling water before it is poured on the powdered bark. An infusion made with this addition contains a greater quantity of cinchonia than the ordinary infusion, in the proportion of 7 to 6; and the salt being a sulphate, it is more active in its effects. This infusion is slightly turbid, has a pale, pinkish-yellow colour, evolves more of the aromatic odour of the bark than the decoction, and has an equal degree of bitterness and astringency. It ferments, spontaneously, in the course of a few days during summer. It affords precipitates with the alkaline carbonates, lime-water, the salts of iron, and of zinc, nitrate of silver, bichloride of mercury, arsenious acid, acetate and diacetate of lead, carbonate of potassa, and tartar emetic; the aqueous infusions and decoctions of chamomile flowers, calumba, cascarilla, horse-radish, cloves, catechu, orange-peel, foxglove, senna, rhubarb, valerian, simaruba, and elm bark.

1 The other species of cinchona may be used in the same manner and proportions.

Any considerable portion of the tinctures also produces precipitates in this infusion. Some of these take place immediately, others not till after several hours have elapsed: the febrifuge virtue is perhaps not destroyed by them, but the mixtures are certainly rendered inelegant. Sulphuric acid destroys the bitterness of the infusion, but not its astringency; and adds considerably to its efficacy.

Medical properties and uses. - The cinchona in this form agrees better with most stomachs than when in powder; but its powers are necessarily diminished. It is chiefly serviceable in dyspepsia, and convalescences, particularly after the maturation of the pustules in ecthyma vulgare. The dose is from f j. to f ij., three or four times a day.